U3 - 3-D6C Power Shift Operacion

D6C TRACTOR / POWERSHIFT / 10K11940-UP (MACHINE) POWERED BY 330... 330... Page Page 1 of 40 40

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Producto: TRACK-TYPE TRACTOR Modelo: D6C TRACK-TYPE TRACTOR 10K Configuración: D6C TRACTOR / POWERSHIFT / 10K11940-UP (MACHINE) POWERED BY 3306 ENGINE

Operación de Sistemas D6 TRACTOR TRACTOR POWER TRAI N Número de medio -REG00615-0 -REG00615-04 4

Fecha de publicación -01/05/ 1974

Fecha de actualización actualización -10/10/ 2001

Systems Operations

Introduction NOTE: For Specifications with illustrations, make reference to POWER TRAIN SPECIFICATIONS FOR D6 TRACTORS, Form No. REG01694. If the Specifications in Form REG01694 are not the same as in the Systems Opertion and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications in the book with the latest date.

General Information - (Power Shift)

LOCATION OF COMPONENTS 1. Transmission hydraulic controls. 2. Universal joint. 3. Diesel engine. 4. Steering clutches. 5. Final drive. 6. Range transmission. 7. Torque divider. 8. Tracks.

Power from the diesel engine (3) is transmitted from the engine flywheel to the torque divider (7) through

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universal joint (2). The torque divider output shaft drives sun gears and planet gears in the transmission. Five planetary gear trains, each with its own clutch, provide three speeds in either forward or reverse. The desired tractor speed is manually selected by the operator but hydraulic oil, directed by the transmission hydraulic controls (1), engages the clutches in the transmission. A bevel pinion in the transmission group, transmits power from the transmission (6) to the bevel gear. The power is transmitted through the steering clutches cl utches (4) into the final drives (5), to the sprockets which drive the tracks (8). The steering clutch and bevel gear case houses the bevel gear, steering clutches and brakes. The steering clutches are of the multiple-disc type, held in engagement by springs. The clutches are hydraulically controlled. The brakes are of the contracting-band-type and are mechanically actuated.

General Information - (Direct Drive)

LOCATION OF COMPONENTS 1. Transmission. 2. Flywheel clutch. 3. Diesel engine. 4. Steering clutch. 5. Final drive. 6. Universal joint. 7. Tracks.

Power from the diesel engine (3) is transmitted from the engine to the flywheel clutch (2). The flywheel clutch is engaged and disengaged manually. The output shaft of the flywheel clutch drives the upper shaft in the transmission (1) through a universal joint (6). The transmission provides gear selections for five forward and four reverse speeds, selected manually. The bevel pinion, at the rear of the transmission, transmits the power to the bevel gear. The power is transferred through the steering clutches (4) into the final drives (5), to the sprockets which drive the tracks (7). The steering clutch and bevel gear case houses the bevel gear, steering clutches and brakes. The steering clutches are of the multiple-disc type held in engagement by springs. The clutches are hydraulically controlled. The brakes are of the contracting-band-type and are mechanically actuated.


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Transmission Hydraulic Controls (Power Shift) Serial Numbers: 10K1-10K8974 , 24U246-Up, 47J147J2879 , 56J1-Up, 69J1-69J2643, 69U1-69U366 *

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*

Including 10K8977 and 10K8981-10K8996.

**

Including 47J2885.

HYDRAULIC CONTROLS (FIRST SPEED FORWARD) 1. Torque converter. 2. Body of the relief valve for converter outlet. 3. Relief valve for converter outlet. 4. Air cooled oil cooler (Later machines only). 5. Oil cooler bypass valve (Later machines only). 6. Water cooled oil cooler. 7. Lubrication line to front of transmission. 8. Lubrication relief valve. 9. Lubrication line to rear of transmission. 10. Hydraulic control for the steering clutch. 11. Flow control valve. 12. Load piston. 13. Body of the pressure control valve. 14. Scavenge oil pump. 15. Oil reservoir for the torque converter. 16. Check valve. 17. Relief valve for converter inlet. 18. Body of the sequence relief valve. 19. Modulation valve. 20. Pressure differential valve. 21. Pressure relief valve. 22. Oil filter. 23. Safety and selection valve body. 24. Spool for direction selection. 25. Oil reservoir. 26. Magnetic strainer. 27. Oil pump. 28. Spool for speed selection. 29. Safety valve. A. Pressure tap for the outlet from the torque converter. B. Pressure tap for lubrication. C. Pressure tap for the inlet to the torque converter. D. Pressure tap for the sequence relief valve. E. Pressure tap for the speed clutch. F. Pressure tap for the direction clutch. G. Pressure tap for the pump.

The transmission hydraulic controls are made up of a pump, filter, control valves, a selector lever and a linkage mechanism. The hydraulic controls send oil to the clutches in the transmission. Oil not used by the clutches is sent through relief valve (21) to inlet relief valve (17) for the torque converter. The location of transmission oil pump (27) is on the left rear face of the flywheel housing. The pump is driven by the engine flywheel. The pump pulls the oil from reservoir (25). The pump sends oil to filter (22)


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on the left side of the engine. From the filter, the oil goes to pressure relief valve (21) on the torque divider housing and to the hydraulic controls (10) for the steering clutches. Relief valve (21) keeps the pressure of the oil to the hydraulic controls at approximately 350 psi (24.6 kg/cm 2) maximum. The oil from relief valve (21) goes to flow control valve (11). Flow control valve (11) prevents the flow of oil to the hydraulic controls from going over 21.4 ± 2 U.S. gpm (81.0 ± 7.5 lit/min). The extra oil goes to inlet relief valve (17) for the torque converter. Oil from the flow control valve goes to pressure control valve body (13). The pressure control valve is made up of two valves: modulation valve (19) and pressure differential valve (20). The modulation valve prevents sudden clutch engagement. The pressure differential valve keeps a difference in the pressure between the speed clutch and direction clutch. Both valves work in combination to engage a speed clutch before a direction clutch is engaged. This arrangement provides for smooth engagement of the transmission and allows most of the load to be taken up by the direction clutches. Oil, at speed clutch pressure, goes from the pressure control valve body (13) through a passage to safety and selector valve body (23). The oil goes through the safety and selection valve body to speed selection spool (28). The speed selection spool is in a position to send oil to one of the three speed clutches. The speed selection spool is connected by linkage to the selection lever of the transmission. The position of speed selection spool (28) is controlled by the position of the selection lever. Oil, at direction clutch pressure, goes through a passage in pressure control valve body (13) to safety and selector valve body (23). The oil goes through the safety and selector valve body to direction selection spool (24). The direction selection spool is in a position to send oil to one of the two direction clutches. The direction selection spool is connected by linkage to the selection lever of the transmission. The position of direction selection spool (24) is controlled by the position of the selection lever. The location of the transmission selection lever is at the left side of the operator's seat. The mechanical linkage connects the selection lever to the selection spools. Speed shifts are made by the movement of the selection lever to the front or back. Direction shifts are made by the movement of the selection lever to the left or right.

Operation When the engine is started, with the selection lever in NEUTRAL, oil goes into flow control valve (11). The oil goes through an orifice in the valve plunger. The orifice decreases the pressure of the oil. The oil that goes through the orifice adds with the force of the spring and tries to move the plunger to the left. The oil from the filter at the left end of the plunger tries to move the plunger to the right. When the pressure of the oil at the left end of the plunger becomes higher than the force of the spring and the pressure of the oil around the spring, the plunger moves to the right. This closes the passages in the plunger from the filter. No oil can now go to the left end of the plunger. The pressure of the oil at the left end of the plunger becomes lower as it goes through the orifice. The force of the spring can now move the plunger to the left and the sequence starts again. This prevents the flow of oil to the pressure control valve from going over 21.4 ± 2 U.S. gpm (81.0 ± 7.5 lit/min). The oil goes from the flow control contro l valve (11) to pressure control valve body (13). Since the engine was just started, the pressure of the oil in the system is low. The spring holds differential valve (20) closed. Modulation valve (19) is held open by the force of its spring. The position of the modulation valve lets the oil go around the spool and out of valve body (13). The oil to the differential valve is stopped by its spool. The oil then goes to selection and safety valve body (23). The oil fills the chamber of safety valve (29). At the same time, the position of speed selection spool (28) lets the oil start to fill the No.3 clutch. When the area behind the piston in the No. 3 clutch is filled with oil, the pressure of the oil increases. The pressure will cause a compression of the spring for safety valve (29). The increase in pressure will also move modulation valve (19) against the force of its spring. The movement of the modulation valve (19) closes the passage to the selection and safety valve body (23). This stops the increase in pressure in the speed clutch for a short period of time. At the same time, the increase in the pressure in the speed clutch moves differential valve (20) against the


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D6C TRACTOR / POWERSHIFT / 10K11940-UP (MACHINE) POWERED BY 330... Page 5 of 40

force of its spring. The differential valve moves until the orifices in the spool are opened to a passage that goes to selection and safety valve body (23). Oil goes through the passage to the selection and safety valve body. The position of speed selection spool (28) keeps t he oil from going to a direction clutch. The differential valve also closes a passage from valve body (13) to the reservoir. The movement of the differential valve lets oil go through the center of the differential valve to check valve (16). The check valve moves and closes a passage from valve body (13) to the reservoir. When both of the passages are closed, pressure oil goes through an orifice in check valve (16) to the chamber behind load piston (12). As the pressure of the oil in the chamber behind load piston (12) increases, the load piston will move toward the modulation valve (19). The pressure of the oil behind the load piston and the force of the spring will move the modulation valve. The modulation valve opens the passage from the flow control valve (11) to the selection and safety valve body (23). This causes the pressure of the oil in the speed clutch to increase. As the pressure in the speed clutch increases, modulation valve (19) moves and stops the oil to the speed clutch again. This causes differential valve (20) to again move against the force of its spring. The oil can again go through the orifice in check valve (16) to the chamber behind load piston (12). The pressure of the oil behind the load piston and the force of the spring again move the modulation valve. The modulation valve again open and lets oil go to the speed clutch. This cycle takes place again and again until the load piston moves completely against its stop. Speed clutch pressure is then at a maximum of approximately 350 psi (24.6 kg/cm2). The pressure stopped by direction selection spool (24) and felt on the load piston (12) is approximately 55 psi (3.9 kg/cm 2) less than the speed clutch pressure. This gradual increase in pressure is called modulation. Modulation valve (19) gives modulation for all the clutches (speed and direction). The force of the spring which is acting on the end of differential valve (20) is approximately 55 psi (3.9 kg/cm2) the same as the pressure acting on the opposite end. Thus the valve will balance at a point where the pressure in the direction clutch is about 55 psi (3.9 kg/cm2) less than the pressure in the speed clutch. When the selection lever is moved from NEUTRAL to FIRST FORWARD, speed selection spool (28) moves to the left. The movement of spool (28) lets oil in the No. 3 clutch go to reservoir (25) and lets the oil from the modulation valve go to the No. 5 clutch. At the same time, speed selection spool (28) opened a passage to direction selection spool (24). The direction selection spool is in a position to let oil go to the No.1 clutch. As the pressure in the No.3 clutch decreases, the force of the spring moves differential valve (20). Differential valve (20) moves and opens a passage to reservoir (25). The pressure in the direction clutch circuit decreases. The oil fills the No.5 speed clutch. As the pressure in the piston behind the No.5 clutch increases, the pressure is felt at the bottom of differential valve (20). The differential valve moves against the force of its spring. Differential valve moves up and closes the passage to reservoir (25). Oil now goes through the differential valve and out valve body (13). The oil goes through a passage in valve body (23) to the No.1 clutch. The oil starts to fill the No.1 clutch. At this time, the modulation valve (19) and load piston (12) go through the modulation sequence. The modulation valve and load piston go through the modulation sequence until the full pressures for operation are reached in the speed and direction clutch circuits. The hydraulic controls are now in the positions shown in the schematic (FIRST SPEED FORWARD). The same sequence is done for each shift. When the transmission selection lever is moved, speed selection spool (28) moves and decreases the pressure of the oil in the clutch circuits. At the same time, speed selection spool (28) opens passages for pressure oil to the clutches for the next speed. As the pressures in the clutch circuits increase, the speed clutch and then the direction clutch are engaged. When the full pressures for operation are reached, the machine will be in the next speed. The operation of the hydraulic controls is the same when both speed and direction are changed.

Safety Valve The safety valve (29) is a mechanism which moves the selection lever to the NEUTRAL position when the pressure of the oil in the hydraulic controls goes below 100 psi (7.0 kg/cm 2). The safety valve will cause the

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selection lever to move from any speed position to the NEUTRAL position if the pressure is below 100 psi (7.0 kg/cm2) for 10 to 30 seconds. This arrangement makes sure that the selection lever is in the NEUTRAL position when the machine is started. When the selection lever is in the NEUTRAL position a direction clutch is not engaged. When the machine is operating, the pressure of the oil in the chamber between the safety valve stem and the safety valve is high enough to put the spring under compression. This holds the valve aw ay from the linkage for the selection lever. If the pressure of the oil is low (engine stopped), the oil is slowly pushed out of the chamber by the force of the spring. The spring will then move to the right and cause the safety valve to move to the right. The safety valve moves to the right until it is in contact with the linkage for the selection lever. At this point, the force of the spring will move the safety valve until selection spools (24) and (28) are in the NEUTRAL position. The selection lever on the transmission control console will also move to the NEUTRAL position. A ball check valve keeps the oil in the chamber when a shift is made to another direction or speed. This prevents the safety valve from shifting the controls to NEUTRAL during the sudden decrease and increase in pressure as the shift is made.

Relief Valve For Torque Converter Outlet The relief valve (3) for the converter outlet keeps the pressure in the torque converter constant by controlling the rate that oil is released from the torque converter. Pressure oil from torque converter (1) goes into housing (2) for the relief valve. It goes through a hole in the valve spool into the chamber between the slug and valve spool. The pressure oil can now move the relief valve against the force of the spring. When the pressure of the oil in the chamber becomes higher than the force of the spring, the valve spool moves. The movement of the valve spool opens a passage to the oil cooler bypass valve (5). The valve spool will move and release pressure oil from the torque converter until the pressure of the oil in the torque converter is approximately 42 psi (2.9 kg/cm 2).

Oil Cooler Bypass Valve - (Later Machines) The oil cooler bypass valve (5) controls the amount of oil that can go through air cooled oil cooler (4). The bypass valve is controlled by the temperature of the oil from relief valve (3) for torque converter outlet. When the temperature of the oil is less than 105° F (41° C), valve (5) is open and lets all the oil go to water cooled oil cooler (6). When the temperature of the oil is 105° F (41° C), valve (5) starts to close and lets most of the oil go through air cooled oil cooler (4). When the temperature of the oil is 185° F (85° C), valve (5) closes all the way and lets all the oil go through air cooled oil cooler (4) to water cooled oil cooler (6). From water cooled oil cooler (6), the oil goes to lubrication relief valve (8).

Transmission Hydraulic Controls (Power Shift) Serial Numbers: 10K8975-Up , 47J2880-Up , 69J2644-Up and 69U367-Up *

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*

Excluding 10K8977 and 10K8981-10K8996.

**

Excluding 47J2885.


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HYDRAULIC CONTROLS (FIRST SPEED REVERSE) 1. Torque converter. 2. Body of relief valve for converter outlet. 3. Relief valve for converter outlet. 4. Air cooled oil cooler. 5. Oil cooler bypass valve. 6. Water cooled oil cooler. 7. Lubrication line to front of transmission. 8. Lubrication relief valve. 9. Lubrication line to rear of transmission. 10. Hydraulic control for steering clutches. 11. Load piston. 12. Body of pressure control valve. 13. Scavenge oil pump. 14. Oil reservoir for torque converter. 15. Check valve. 16. Relief valve for converter inlet. 17. Body of sequence relief valve. 18. Modulation valve. 19. Pressure differential and safety valve. 20. Pressure relief valve. 21. Oil filter. 22. Body of selector valve. 23. Spool for direction selection. 24. Oil reservoir. 25. Magnetic screen. 26. Transmission oil pump. 27. Spool for speed selection. A. Pressure tap for converter outlet. B. Pressure tap for lubrication. C. Pressure tap for converter inlet. D. Pressure tap for sequence relief valve. E. Pressure tap for speed clutches. F. Pressure tap for direction clutches. G. Pressure tap for transmission oil pump.

The transmission hydraulic controls are made up of a pump, filter, control valves, a selector lever and a linkage mechanism. The hydraulic controls send oil to the clutches in the transmission. Oil not used by the clutches is sent through pressure relief valve (20) to inlet relief valve (16) for the torque converter. The location of transmission oil pump (26) is on the left rear face of the flywheel housing. The pump is driven by the engine flywheel. The pump pulls the oil from reservoir (24) and sends it to filter (21) on the left side of the engine. From the filter, the oil goes to pressure relief valve (20) on the torque divider housing and to the hydraulic controls (10) for the steering clutches. Relief valve (20) keeps the pressure of the oil to the hydraulic controls at approximately 350 psi (24.6 kg/cm 2) maximum. The oil from relief valve (20) goes to pressure control valve body (12). The extra oil goes to the inlet relief valve (16) for the torque converter. The pressure control valve is made up of two valves: modulation valve (18) and pressure differential and safety valve (19). The modulation valve prevents sudden clutch engagement. The pressure differential val ve keeps a difference in the pressure between the speed clutch and direction clutch. Both valves work in combination to engage a speed clutch before a direction clutch is engaged. This arrangement provides for smooth engagement of the transmission and allows most of the load to be taken up by the direction clutches. The safety valve keeps the transmission from engaging when the engine is started with the transmission in a speed position. Oil, at speed clutch pressure, goes from the pressure control valve body (12) through a passage to selector


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valve body (22). The oil goes through the selector valve body to speed selection spool (27). The speed selection spool is in a position to send oil to one of the three speed clutches. The speed selection spool is connected by linkage to the selection lever of the transmission. The position of speed selection spool (27) is controlled by the position of the selection lever. Oil, at direction clutch pressure, goes through a passage in pressure control body (12) to selector valve body (22). The oil goes through the selector valve body to direction selection spool (23). The direction selection spool is in a position to send oil to one of the two direction clutches. The direction selection spool is connected by linkage to the selection lever of the transmission. The position of direction selection spool (23) is controlled by the position of the selection lever. The location of the transmission selection lever is at the left side of the operator's seat. The mechanical linkage connects the selection lever to the selection spools. Speed shifts are made by the movement of the selection lever to the front or back. Direction shifts are made by the movement of the selection lever to the left or right.

Operation When the engine is started, with the selection lever in NEUTRAL, oil goes through a passage in valve body (12) to modulation valve (18). The oil goes around the modulation valve to differential and safety valve (19). The oil goes through a passage in the valve. Part of the oil goes out of valve body (12) to selection valve body (22). The position of speed selection spool (27) lets this oil start to fill the No. 3 clutch. Part of the oil opens the poppet valve in differential and safety valve (19). This oil goes into the chamber between valve (19) and the cover of valve body (12). Since valve (19) is against the cover, a passage is open from the chamber to the right end of speed selection spool (27). When speed selection spool (27) is in the NEUTRAL position, the passage is closed to reservoir (24). The pressure of the oil in the chamber increases. Valve (19) moves away from the cover of valve body (12). When the area behind the piston in the No. 3 clutch is filled with oil, the pressure of the oil increases. The increase in pressure will move modulation valve (18) against the force of its spring. The movement of the modulation valve (18) closes the passage from the transmission oil filter (21). This stops the increase in pressure in the speed clutch for a short period of time. At the same time, the increase in the pressure in the speed clutch moves differential and safety valve (19) against the force of its spring. Differential and safety valve moves until the orifices in the spool are opened to a passage that goes to selection valve body (22). The position of speed selection spool (27) keeps the oil from going to a direction clutch. The differential and safety valve also closes a passage from valve body (12) to the reservoir. The movement of the differential and safety valve lets oil go through the center of the differential and safety valve to check valve (15). The check valve moves and closes a passage from valve body (12) to the reservoir. When both of the passages are closed, pressure oil goes through an orifice in check valve (15) to the chamber behind load piston (11). As the pressure of the oil in the chamber behind load piston (11) increases, the load piston will move toward the modulation valve. The pressure of the oil behind the load piston and the force of the spring will move the modulation valve (18). The modulation valve opens the passage from the filter to differential and safety valve (19). The position of valve (19) lets the oil go from valve body (12) to selection body (22). This causes the pressure of the oil in the speed clutch to increase. As the pressure in the speed clutch increases, modulation valve (18) moves and stops the oil to the speed clutch again. This causes differential and safety valve (19) to again move against the force of its spring. The oil can again go through the orifice in check valve (15) to the chamber behind load piston (11). The pressure of the oil behind the load piston and the force of the spring again move the modulation valve. The modulation valve again opens and lets oil go to the speed clutch. This cycle takes place again and again until the load piston moves completely against its stop. Speed clutch pressure is then at a maximum of approximately 350 psi 24.6 kg/cm2). The pressure stopped by direction selection spool (23) and felt on the load piston (11) is approximately 55 psi (3.9 kg/cm 2) less than the speed clutch pressure. This gradual increase in pressure is called modulation. Modulation valve (18) gives modulation for all the clutches (speed and direction).


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The force of the spring which is acting on the end of differential and safety valve (19) is approximately 55 psi (3.9 kg/cm2) the same as the pressure acting on the opposite end. Thus the valve will balance at a point where the pressure in the direction clutch is about 55 psi (3.9 kg/cm 2) less than the pressure in the speed clutch. When the selection lever is moved from NEUTRAL to FIRST REVERSE, speed selecti on spool (27) moves to the left. The movement of spool (27) lets oil in the No.3 clutch go to reservoir (24) and to the No.5 clutch. At the same time, speed selection spool (27) opened a passage to direction spool (23). The direction selection spool is in a position to let oil go to the No.2 clutch. As the pressure in the No.3 clutch decreases, the force of the spring moves differential and safety valve (19). Differential and safety valve (19) moves and opens a passage to reservoir (24). The pressure in the direction clutch circuit decreases. The oil fills the No.5 clutch. As the pressure in the piston behind the No.5 clutch increases, the pressure is felt at the bottom of differential and safety valve (19). The differential and safety valve moves against the force of its spring and closes the passage to reservoir (24). Oil goes through the differential and safety valve and out valve body (12). The oil goes through a passage in valve body (22) to the No.2 clutch. The oil starts to fill the No.2 clutch. At this time, the modulation valve (18) and load piston (11) go through the modulation sequence. The modulation valve and load piston go through the modulation sequence until the full pressures of operation are reached in the speed and direction clutches. The hydraulic controls are now in the positions shown in the schematic. The same sequence is done for each shift. When the transmission selection lever is moved, speed selection spool (27) moves and decreases the pressure of the oil in the clutch circuits. At the same time, speed selection spool (27) opens passages for pressure oil to the clutches for the next speed. As the pressures in the clutch circuits increase, the speed clutch and then the direction clutch are engaged. When the full pressures of operation are reached, the machine will be in the next speed. The operation of the hydraulic controls is the same when both speed and direction are changed.

Safety Valve The safety valve (19) prevents movement of the machine if the engine is started in a speed position or if the pressure in the hydraulic controls decreases. When the machine is operating with the selection lever in a speed position, pressure oil in the chamber between valve (19) and the cover of valve body (12) keeps valve (19) away from the cover. The position of the spool lets oil go the speed and direction clutches. The clutches for that speed are engaged and the operation of the transmission hydraulic controls is normal. When the pressure of the oil in the chamber is low (engine stopped), valve (19) is all the way against the cover of valve body (12). Valve (19) will not move until the pressure in the chamber increases. When the engine is started with the selection lever in a speed position, the oil from modulation relief valve (18) goes to valve (19). Since the pressure in the chamber is low, valve (19) is all the way against the cover. Oil goes through a passage in the valve. Part of the oil goes out of valve body (12) to selection valve body (22). This oil starts to fill a speed clutch. Part of the oil from modulation valve (18) opens the poppet valve in valve (19). This oil goes into the chamber between valve (19) and the cover of valve body (12). Since valve (19) is against the cover, a passage is open from the chamber to the right end of speed selection spool (27). When speed selection spool (27) is in a speed position, the right end is open to reservoir (24). The pressure of the oil in the chamber between valve (19) and valve body (12) does not increase. Valve (19) does not move and stops the oil to the direction clutch. Since both a speed and direction clutch must be engaged in the transmission, the machine will not move. The poppet valve in valve (19) prevents the valve from moving all the way against the cover when the transmission makes a shift.


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The selection lever must be moved to NEUTRAL before oil can go to the direction clutch circuit. When the selection lever is in NEUTRAL, speed selection spool (27) closes the passage at the right end of the spool to reservoir (24). The pressure in the chamber betwee n valve (19) and the cover can increase. Valve (19) moves and oil can go to the direction clutch circuit.

Relief Valve For Torque Converter Outlet The relief valve (3) for the converter outlet keeps the pressure in the torque converter constant by controlling the rate that oil is released from the torque converter. Pressure oil from torque converter (1) goes into housing (2) for the relief valve. It goes through a hole in the valve spool into the chamber between the slug and valve spool. The pressure oil can now move the relief valve against the force of the spring. When the pressure of the oil in the chamber becomes higher than the force of the spring, the valve spool moves. The movement of the valve spool opens a passage to oil cooler bypass valve (5). The valve spool will move and release pressure oil from the torque converter until the pressure of the oil in the torque converter is approximately 42 psi (2.9 kg/cm 2).

Oil Cooler Bypass Valve The oil cooler bypass valve (5) controls the amount of oil that can go through air cooled oil cooler (4). The bypass valve is controlled by the temperature of the oil from relief valve (3) for torque converter outlet. When the temperature of the oil is less than 135° F (57° C), valve (5) is open and lets all the oil go to water cooled oil cooler (6). When the temperature of the oil is 135° F (57° C), valve (5) starts to close and lets most of the oil go to water cooled oil cooler (6) and some of the oil go through air cooled oil cooler (4). When the temperature of the oil is 170° F (77° C), valve (5) closes all the way and lets all the oil go through air cooled oil cooler (4) to water cooled oil cooler (6). From water cooled oil cooler (6), the oil goes to lubrication relief valve (8).

Torque Divider (Power Shift) The torque divider connects the engine to the planetary transmission. This connection is both a hydraulic connection and a mechanical connection. The hydraulic connection is through a torque converter. The mechanical connection is through a planetary gear set. The torque converter uses oil from the transmission hydraulic controls to multiply the torque to the transmission. When the machine is working against a low load, the torque multiplication is low. When the machine is working against a high load, the torque multiplication is higher. A higher torque can then be sent to the transmission during high load conditions. The planetary gear set also multiplies the torque from the engine by making an increase in the mechanical advantage through its gears. This torque multiplication also makes an increase as the load on the machine becomes higher. During no load conditions, neither the torque converter nor the planetary gear set can multiply the torque from the engine.


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TORQUE DIVIDER OPERATION 1. Torque divider housing. 2. Rotating housing. 3. Diesel engine flywheel. 4. Ring gear. 5. Impeller. 6. Sun gear. 7. Outlet port. 8. Turbine. 9. Output shaft. 10. Planet carrier. 11. Inlet port. 12. Planet gears. 13. Carrier. 14. Stator.

The torque divider is installed into flywheel (3). Torque divider housing (1) is installed on the engine flywheel housing. Output shaft (9) is connected to the planetary transmission. A bearing at the rear of housing (1) holds the torque divider in alignment with the flywheel. The planetary gear set is made up of a sun gear (6), planet carrier (10), planet gears (12) and ring gear (4). Sun gear (6) is connected to flywheel (3) by splines. Planet carrier (10) is connected to output shaft (9) by splines. Planet gears (12) are held by planet carrier (10) and are engaged with the sun gear (6) and ring gear (4). The torque converter is made up of housing (2), impeller (5), turbine (8) and stator (14). Housing (2) is connected to flywheel (3) by splines. Impeller (5) is connected to housing (2) by bolts. The turbine (8) is connected to ring gear (4) by splines. Stator (14) is connected to carrier (13) by bolts. Carrier (13) is connected to the torque divider housing (1) and can not turn. Oil for the operation of the torque converter is from the transmission hydraulic controls. A relief valve for converter inlet controls the pressure of the oil to the torque converter. A relief valve for converter outlet controls the pressure of the oil in the converter.

Operation The torque converter is driven by the engine through housing (2). The planetary gear set is driven by the engine through sun gear (6). These connections let the torque output of the engine go in two separate directions. Because of the larger radius of ring gear (4), most of this torque is sent by the torque converter through the ring gear to planet gears (12). The remainder of the torque is sent by sun gear (6) to planet gears (12). If planet carrier (10) has no resistance to rotation (no load), sun gear (6), planet gears (12), planet carrier (10) and ring gear (4) will turn at the same speed. The torque from the converter and from the planetary gear set is now through the planet carrier to output shaft (9) and the planetary transmission. Neither the torque converter nor the planetary gear set can multiply the torque from the engine when they are turning at the same speed. When the machine has a load, planet carrier (10) has a resistance to rotation. Since sun gear (6) is turning at the rpm of the engine, this resistance to rotation causes planet gears (12) to turn on their shafts. Their rotation is opposite the rotation of ring gear (4). This causes a reduction in the speed of the ring gear. Since turbine (8) is connected to the ring gear, a reduction in speed will cause the torque converter to multiply the torque of the engine from housing (2). The torque multiplication is sent to planet carrier (10) and the output shaft through the ring gear.


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With the reduction in the speed of the ring gear, the torque of the engine through sun gear (6) and the planetary gear set also multiplies. This torque multiplication is also sent to planet carrier (10) and the output shaft. If the resistance to rotation of planet carrier (10) becomes higher (more load on the machine), the ring gear will make more of a reduction in speed. The slower speed will let the torque multiplication through both the torque converter and the sun gear become higher. If the resistance to rotation of the planet carrier becomes high enough, the ring gear will stop. During some very high load conditions, the rotation of the planet carrier and the output shaft will also stop. This will cause the ring gear to turn slowly in the opposite direction. At this time the torque multiplication of the torque converter and the sun gear is at its maximum.

Operation of the Torque Converter Oil for the operation of the torque converter goes through inlet port (11) in carrier (13) to impeller (5). The rotation of the impeller gives force to the oil. The impeller sends the oil toward the outside of the impeller, around the inside of housing (2) to turbine (8). The force of the oil hitting the blades of the turbine causes the turbine to turn. Since the turbine is connected to ring gear (4), torque is sent to planet gears (12). At this point in time, the torque given to the turbine by the force of the oil from the impeller can not be more than the torque output of the engine to the impeller. As the oil goes from the turbine, it is moving in a direction opposite to the direction of impeller (5) rotation. Stator (14) causes the oil to change direction. Since the stator is connected to carrier (13) and can not turn, most of the oil is sent back to impeller (5). The remainder of the oil goes from the stator through outlet port (7) to the oil cooler and the transmission lubrication system.

FLOW OF OIL THROUGH TORQUE CONVERTER 2. Housing. 5. Impeller. 8. Turbine. 14. Stator.

The force of the oil from the stator can now add to the torque output from the engine to the impeller. This extra force can give an increase to the torque output of the engine to the turbine. The larger the difference between the speeds of the impeller and the turbine, the larger the amount of force of the oil from the stator. Since it is the load on the machine that changes the speed of the turbine, the higher the load, the larger the difference in the speeds of the impeller and the turbine. It is then the different loads on the machine that control the amount of torque multiplication that the force of the oil from the stator can add.

Torque Divider Lubrication Oil for the lubrication of the torque divider bearings and the planetary gear set is from the supply used for the operation of the torque converter. The bearings are constantly running in oil. Bearings and gears in the planetary gear set and the pilot bearing get lubrication through passages in the output shaft. The output shaft bearing gets lubrication from normal oil leakage by a piston ring-type seal.

Transmission (Power Shift) The transmission is composed of two planet carriers containing five planetary systems and five hydraulicallyactuated clutches. The two front clutches (No. 1 and No. 2) are directional clutches, determining forward or


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reverse direction, respectively. The three rear clutches (No. 3, No. 4 and No. 5) are speed clutches providing second, third and first speed, respectively.

Neutral When the transmission control lever is in the NEUTRAL slot, the No. 3 clutch is engaged. However, the construction of the selector control valve is such that pressure oil is not available to the directional valve spool. (A directional clutch and a speed clutch must be engaged to transmit torque to the bevel pinion.) The No.3 clutch ring gear is held stationary by the engaged clutch. The ring gear is connected to the No.2 carrier (rear carrier); therefore, the No.2 carrier is held stationary. The power flow is transmitted through the input shaft which can be used as a power take-off.

NEUTRAL (No.3 Clutch Engaged) 1. No.5 planet gear. 2. No.5 clutch ring gear. 3. No.5 clutch. 4. No.4 inner planet gear. 5. No.4 clutch ring gear. 6. No.4 clutch. 7. No.3 planet gear. 8. No.3 clutch. 9. No.3 clutch ring gear. 10. No.2 clutch. 11. No.2 clutch ring gear. 12. No.1 clutch. 13. No.1 clutch ring gear. 14. No.2 inner planet gear. 15. No.2 carrier.


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16. No.1 sun gear. 17. Transfer gear. 18. No.2 sun gear. 19. Input shaft. 20. Bevel pinion drive gear. 21. No.3 sun gear. 22. Bevel pinion. 23. No.1 carrier. 24. No.5 sun gear. 25. No.4 sun gear. 26. No.4 outer planet gear. 27. Output shaft. 28. No.2 outer planet gear. 29. No.1 planet gear.

First Speed Forward In first speed forward, the No. 1 and No. 5 clutches are engaged holding the No. 1 and No. 5 clutch ring gears stationary. The input shaft drives the No. 1 sun gear. The sun gear meshes with the No. 1 planet gears, forcing them to rotate within the No. 1 clutch ring gear. This forces the No. 1 carrier to rotate in the same direction as the input shaft. The No. 1 and No. 2 carriers and the No. 3 clutch ring gear are connected mechanically; therefore, the No. 2 carrier rotates also. The torque to the output shaft is applied by both the No. 3 planet gears acting on the No. 3 sun gear, and the No. 5 planet gears acting on the No. 5 sun gear. The power is then transmitted to the bevel pinion by the transfer gear.

POWER FLOW-FIRST SPEED FORWARD (No. 1 and No. 5 Clutches Engaged) 1. No.5 planet gear. 2. No.5 clutch ring gear. 3. No.5 clutch.


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7. No.3 planet gear. 9. No.3 clutch ring gear. 12. No.1 clutch. 13. No.1 clutch ring gear. 15. No.2 carrier. 16. No.1 sun gear. 17. Transfer gear. 19. Input shaft. 20. Bevel pinion drive gear. 21. No.3 sun gear. 22. Bevel pinion. 23. No.1 carrier. 24. No.5 sun gear. 27. Output shaft. 29. No.1 planet gear.

Second Speed Forward In second speed forward, the No. 1 and No. 3 clutches are engaged, holding the No. 1 clutch ring gear and the No. 3 clutch ring gear and No. 2 carrier stationary. The torque, therefore, is transmitted from the No. 1 sun gear to the No. 1 planet gears, through the No. 3 planet gears, to the output shaft. The output shaft, in turn, transmits torque to the bevel pinion.

POWER FLOW-SECOND SPEED FORWARD (No.1 and No.3 Clutches Engaged) 7. No.3 planet gear. 8. No.3 clutch. 9. No.3 clutch ring gear.


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12. No.1 clutch. 13. No.1 clutch ring gear. 15. No.2 carrier. 16. No.1 sun gear. 19. Input shaft. 23. No.1 carrier. 27. Output shaft. 29. No.1 planet gear.

Third Speed Forward In third speed forward, the No. 1 and No. 4 clutches are engaged, holding the No. 1 and No. 4 clutch ring gears stationary. The No. 1 sun gear and planets drive the No. 1 carrier. The No. 4 sun gear rotates with the carrier and drives the No. 4 inner planet gears which, in turn, drive the outer planet gears. The outer planet gears cause the No. 2 carrier and No. 3 clutch ring gear to rotate in the opposite direction of the No. 1 carrier. The No. 3 clutch ring gear drives the No. 3 planet gears which transmit the torque to the No. 3 sun gear on the output shaft.

POWER FLOW-THIRD SPEED FORWARD (No. 1 and No. 4 Clutches Engaged) 4. No.4 inner planet gear. 5. No.4 clutch ring gear. 6. No.4 clutch. 7. No.3 planet gear. 9. No.3 clutch ring gear. 12. No.1 clutch. 13. No.1 clutch ring gear. 15. No.2 carrier. 16. No.1 sun gear.


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19. Input shaft. 21. No.3 sun gear. 23. No.1 carrier. 25. No.4 sun gear. 26. No.4 outer planet gear. 27. Output shaft. 29. No.1 planet gear.

Second Speed Reverse

POWER FLOW-SECOND SPEED REVERSE (No. 2 and No. 3 Clutches Engaged) 7. No.3 planet gear. 8. No.3 clutch. 9. No.3 clutch ring gear. 10. No.2 clutch. 11. No.2 clutch ring gear. 14. No.2 inner planet gear. 15. No.2 carrier. 18. No.2 sun gear. 19. Input shaft. 21. No.3 sun gear. 23. No.1 carrier. 27. Output shaft. 28. No.2 outer planet gear.


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In second speed reverse, the No. 2 and No. 3 clutches are engaged, holding their respective ring gears stationary. The No. 2 carrier is held stationary by the No. 3 clutch. The No. 2 sun gear drives the No. 2 inner planet gears which, in turn, drive the outer planet gears. The outer planet gears cause the No. 1 carrier to be driven in the opposite direction of the input shaft. The No. 3 planet gears transmit the torque to the No. 3 sun gear on the output shaft, turning the output shaft in the same direction as the input shaft.

First And Third Speeds Reverse For first speed reverse the No. 2 and No. 5 clutches are engaged. The operation is essentially the same as first speed forward. The difference being that the No. 2 gear train is used instead of the No. 1. The extra set of planet gears in the No. 1 carrier causes the No. 1 carrier rotation and therefore the output shaft rotation to be reversed. For third speed reverse the No. 2 and No. 4 clutches are engaged.

Transmission Lubrication Oil from the oil cooler flows to the transmission lubrication relief valve, mounted on the front of the transmission. From here is directed through two passages to the No. 1 and No. 2 planet carriers. The relief valve is a spring-loaded dump valve. When the pressure of the lubricating oil exceeds the force of the dump return spring, the valve moves against the spring allowing excess oil to flow through the orifices in the dump valve, returning to the sump. The oil flows through the No. 1 and No. 2 carrier lubrication tubes. The oil passing through the No. 1 carrier tube flows through a passage in the front bearing cage and lubricates the bearings. An oil manifold directs oil to the passages in the planet gear shafts to lubricate the planet gear shaft bearings in the No. 1 carrier.

TRANSMISSION LUBRICATION 1. Passage in transfer gear case. 2. Bearing drain passage. 3. Passage in bearing cage. 4. Front bearing. 5. Passage through the clutch housing. 6. Passage in front bearing cage. 7. No.1 carrier lubrication tube. 8. No.2 carrier lubrication tube. 9. Transmission lubrication relief valve.


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The oil passing through the No. 2 carrier lubrication tube flows through a passage in the clutch housings to a passage in the transfer gear case. The oil passes through the rear bearing cage and lubricates the No. 2 carrier planet gear shaft bearings. Lateral passages in the plate assembly between the No. 1 and No. 2 clutch housings direct some of the oil to spray on the clutch plates and discs for lubrication and cooling. The other components of the transmission and transfer drive are splash lubricated. The oil is then returned to the sump.

LUBRICATION RELIEF VALVE 1. Port to No.1 planet carrier. 2. Dump valve. 3. Dump valve return spring. 4. Dump chamber. 5. Port to No.2 planet carrier.

Transmission (Direct Drive) The direct drive transmission is of the sliding gear type and is enclosed in a separate case. Two gear selector levers are provided to obtain speed and directional selection. One selector lever controls the shifter fork for selecting forward or reverse. The other selector lever controls three shifter forks for selection of different speeds, as shown in the chart.


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TRANSMISSION GEAR ARRANGEMENT 1. Uppershaft. 2. Countershaft. 3. Bevel pinion shaft. A. Forward and reverse sliding gear. B. First speed gear. C. Second speed gear. D. Third speed gear. E. Fourth speed gear. F. Fifth speed gear. G. Reverse drive gear. H. First speed sliding gear. I. Second speed sliding gear. J. Third speed sliding gear.


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K. Fourth speed sliding gear. L. Fifth speed sliding gear. M. Reverse idler gear.

A locking mechanism actuated by the flywheel clutch control lever locks the sliding gears in position when the flywheel clutch is engaged. The reverse drive gear (G) is always in mesh with the reverse idler gear (M).

TRANSMISSION SHAFT LOCATIONS (FRONT VIEW) 1. Upper shaft. 2. Countershaft. 3. Bevel pinion shaft.

POWER FLOW

Transmission Lubrication Lubricating oil is supplied by the flywheel clutch and transmission oil pump. Oil is delivered through an inlet tube to oil manifold (1), which sprays oil downward over the transmission gears. The transmission lubrication regulator valve (2) located on the front of the transmission case at the end of manifold (1), limits the pressure of the lubricating oil and directs excess oil to the transmission sump. Cored passages (3) in the transmission case carry oil from the valve to the forward bearings of upper shaft (4), countershaft (5) and bevel pinion shaft (6). Drilled passage (7) in shaft (6) carries oil to a cross-drilled passage, which directs the oil to the reverse idler gear bearing. The bearings on the rear of shafts (4), (5) and (6) are splash lubricated.


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SCHEMATIC OF TRANSMISSION LUBRICATION SYSTEM

TRANSMISSION LUBRICATION 1. Manifold. 2. Regulator valve. 3. Passages.


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TRANSMISSION LUBRICATION 4. Upper shaft. 5. Countershaft. 6. Bevel pinion shaft. 7. Drilled passage.

Flywheel Clutch (Direct Drive) The oil clutch transmits torque from the diesel engine flywheel (10) to the transmission input shaft. When the clutch is ENGAGED, the clutch actuating mechanism forces the pressure plates (8) and driven disc assemblies (9) together to rotate as a unit. The clutch is maintained in the ENGAGED position by the overcenter cam action of the cam link and roller assemblies (17) against the clutch loading plate (16).


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FLYWHEEL CLUTCH OPERATION AND LUBRICATION 1. Brake drum. 2. Bearing cage. 3. Clutch shaft. 4. Oil passage in clutch shaft. 5. Oil pump drive gear. 6. Thrust washers. 7. Sliding collar assembly. 8. Pressure plates. 9. Driven disc assemblies. 10. Diesel engine flywheel. 11. Loading plate bearings. 12. Pilot bearing. 13. Clutch shaft rear bearing. 14. Oil passage in clutch hub. 15. Clutch hub.


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16. Clutch loading plate. 17. Cam link and roller assembly. 18. Oil return passage in bearing cage. 19. Oil inlet passage in bearing cage. 20. Oil pump. 21. Rear bearing retainer. 22. Oil pump driven gear. 23. Yoke assembly. 24. Oil pump screen. 25. Oil drain holes in flywheel.

When the flywheel clutch control lever is moved to the DISENGAGED position, yoke assembly (23), sliding collar assembly (7) and cam link and roller assemblies (17), move away from clutch loading plate (16). This allows flywheel (10) and pressure plates (8) to rotate relative to the driven disc assemblies (9), clutch hub (15) and clutch shaft (3). After the clutch is DISENGAGED, rotation of the drive shaft and clutch shaft can be stopped by moving the flywheel clutch control lever forward. This action moves a brake shoe, which is mounted on a spring loaded lever, in contact with brake drum (1), which is bolted to the clutch shaft. A single-section gear-type pump (20) provides pressure oil to cool and lubricate the oil clutch and the hydraulic pump drive gears. The pump operates whenever the diesel engine is running. Oil is supplied to the pump from the bottom of the flywheel housing through screen (24) and a passage in the flywheel clutch housing. After passing through the pump, oil flows to the flow control valve. Oil then flows through a passage in the clutch cover, and flywheel housing to the hydraulic pump drive gears. When the oil pressure reaches approximately 5 psi (0.36 kg/cm 2), oil is permitted to flow through the flywheel clutch. An oil drainback passage (18) prevents the buildup of pressure oil a gainst the seal at the rear of the flywheel clutch housing. The pilot bearing (12) is lubricated by oil which seeps past the spline on the clutch shaft and clutch hub. The pressure plates (8) and driven disc assemblies (9) are cooled by oil which is thrown by centrifugal force of the rotating clutch shaft and hub. The oil then passes through passages (25) in the flywheel and returns to the bottom of the flywheel housing where the lubrication cycle is repeated.

Gear Shift And Interlock Mechanism There are two transmission shift levers and one flywheel clutch lever to control the gear shift and interlock mechanism. The two transmission shift levers are contained in one housing which is bolted to the right side of the transmission case. The flywheel clutch lever is mounted on a bracket bolted to the left rear portion of the tractor frame assembly.


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GEAR SHIFT AND INTERLOCK MECHANISM (Viewed From Rear) 1. Forward-reverse lever. 2. Speed selector lever. 3. Bearing. 4. Lever. 5. Bearing. 6. Forward-reverse shifter fork. 7. Lever. 8. Gate. 9. Fifth speed shifter fork. 10. Guide. 11. Third and fourth speed shifter fork. 12. First and second speed shifter fork. 13. Shifter shaft.

By moving the two control levers, various combin ations of gears can be selected to give five forward and four reverse speeds. The forward or reverse direction is selected by the forward-reverse lever (1) while the speed selector lever (2) is used to select the desired speed. When the tractor is used for belt work or other stationary work, or when idling with the flywheel clutch ENGAGED, keep the forward and reverse lever in the FORWARD position, toward the operator. This will keep the counter-shaft rotating and furnish lubricant to the transmission upper shaft bearings. The three forks (9), (11) and (12) are controlled by the speed selector lever (2). The fork (6) is controlled by the forward and reverse lever (1). The interlock mechanism, attached to the gear shift housing, holds the shifter forks and transmission gears in position when the clutch is ENGAGED.


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GEAR SHIFT AND INTERLOCK MECHANISM (Viewed From Right) 1. Forward-reverse lever. 2. Speed selector lever. 4. Lever. 7. Lever. 9. Fifth speed shifter fork. 10. Guide. 11. Third and fourth speed shifter fork. 12. First and second speed shifter fork. 13. Shifter shaft. 14. Flywheel clutch lever. 15. Plunger (four). 16. Plate. 17. Spring (four). 18. Interlock shaft.

The interlock mechanism consists of spring-loaded plungers (15), which fit into notches on the shifter shafts (13), and an interlock shaft (18), which is connected by a lever and rod to the flywheel clutch control lever (14). The cam on the interlock shaft locks the plungers in the notches on the shifter shafts when the flywheel clutch is ENGAGED, thereby preventing the transmission gears from sliding out of position. When the clutch is DISENGAGED, the interlock shaft is rotated, allowing the plungers to be forced out of the notches as the gears are shifted. Only a small load, created by the spring-loaded plungers, need be overcome to make a shift change.

Steering Clutches, Brakes And Final Drive Steering Clutches And Final Drive The bevel pinion shaft in the transmission, drives the bevel gear. Both ends of the bevel gear shaft (1) are splined into the hub of a steering clutch driving drum. Springs force the pressure plate assembly (4), driving discs (7) and disc assemblies (8) against the driving drum (3). The steering clutches are disengaged by oil pressure acting behind the steering clutch piston (5) which causes the piston to move outward against the steering clutch spring retainer (6). This moves the steering clutch pressure plate (4) out of contact with the discs to disengage the clutch.


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STEERING CLUTCH 1. Bevel gear shaft. 2. Steering clutch release bearing assembly. 3. Steering clutch driving drum. 4. Pressure plate assembly. 5. Steering clutch piston. 6. Steering clutch spring retainer. 7. Driving disc. 8. Disc assembly.

The steering clutch driven drum encloses the pressure plate assembly, driving discs, disc assemblies and driving drum. Teeth on the outer diameter of each disc assembly mesh with teeth in the driven drum. The steering clutch driven drum connects to the final drive flange on the final drive pinion. The final drive hub is splined into the sprocket. The bevel gear, bevel gear shaft, steering clutch and final drive pinion rotate as a unit. Disengaging a steering clutch disconnects the drive between the bevel gear shaft and the final drive pinion.


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FINAL DRIVE 9. Steering clutch driven drum. 10. Final drive pinion flange. 11. Final drive pinion. 12. Idler pinion gear. 13. Final drive gear. 14. Final drive sprocket. 15. Outer bearing adjusting nut. 16. Sprocket shaft. 17. Duo-Cone seals. 18. Sprocket retaining nut. 19. Bearing support assembly.

Steering Clutch Hydraulic Control Filtered pressure oil is delivered by the transmission oil pump to the steering clutch hydraulic control valve housing located on the bevel gear compartment cover.


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STEERING CLUTCH HYDRAULIC CONTROL 1. Shaft. 2. Shaft. 3. Lever. 4. Lever. 5. Plunger.

The steering clutch control levers are connected, through mechanical linkages, to levers on the shafts (1) and (2). When the control levers are pulled to release the steering clutches, shafts (1) and (2) are rotated causing levers (3) and (4) to contact plungers (5) and move them to the rear. The plungers operate control valve spools which direct oil to control pistons (6) in the steering clutch hubs. The oil behind the pistons moves them toward the steering clutches, compressing steering clutch springs (7) and moving pressure plate (8) out of contact with the clutch discs, releasing the clutches.

CONTROL PISTON OPERATION 6. Piston. 7. Spring. 8. Pressure plate.


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Flow of Oil The steering clutch hydraulic control valve acts as a pressure reducing valve to control the amount of oil pressure behind the control pistons in the steering clutch hubs. The oil flow through the valve is as follows: See Fig. 1. Pressure oil enters the control valve spool housing (6) through a port (not shown) in the top of the housing and fills chamber (11). When both steering clutches are engaged, the oil in the chamber is blocked by valve spools (5) and (19) from passing into outlet ports (2) and (17) to the steering clutch hubs. Slots (12) in the valve spools allow a portion of the oil in the chamber to be bled off for lubrication of the operating mechanism in shaft housing (7). The oil level in the housing is maintained by a standpipe (9). The overflow oil flows through the standpipe and lubricates the bevel gear and pinion and the bevel gear shaft bearings. The outlet ports (2) and (17) connect to oil lines which lead to the steering clutch hubs. With the clutches engaged, the oil in the steering clutch hubs and lines is at 0 PSI. The outlet ports are open to the oil sump in the bevel gear compartment through standpipe (8) and slots (1) and (15) in the valve spools.

FIG. 1. FLOW OF OIL-SCHEMATIC Both Clutches Engaged 1. Slots (two). 2. Outlet port. 3. Passage. 4. Cavity. 5. Valve spool. 6. Valve spool housing. 7. Shaft housing. 8. Standpipe. 9. Standpipe. 10. Spring. 11. Chamber. 12. Slots. 13. Plug. 14. Slug. 15. Slots (two). 16. Passage. 17. Outlet port. 18. Cavity. 19. Valve spool. 20. Washer. 21. Spring. 22. Plunger.

See Fig. 2. Either or both steering clutches may be partially released by pulling the steering clutch control levers part way back. When the right steering clutch control lever is pulled part way back, plunger (22) is moved to the rear exerting a force on spring (21) moving valve spool (19) to the rear compressing spring (10). The movement of the valve spool opens outlet port (17) to chamber (11) allowing pressure oil to flow to the right steering clutch control piston, compressing the clutch springs. As the pressure increases behind the clutch control piston, the pressure increase is sensed in cavity (18) through passage (16) in the valve spool. When the combined force of oil pressure in cavity (18) [in front of slug (14)] and the force of spring (10) becomes slightly greater and overcomes the force of spring (21), valve spool (19) moves forward cutting off the flow of pressure oil through port (17). Thus, valve spool (19) is in a balanced position, maintaining a pressure behind the right clutch control piston. The amount of oil pressure is established by the position of plunger (22) which in turn determines the amount of force spring (21) exerts on valve spool (19). The pressure at which the clutches begin slipping depends upon the load being applied to the machine.

FIG. 2. FLOW OF OIL - SCHEMATIC Left Clutch ENGAGED, Right Clutch Slipping 2. Outlet port. 3. Passage. 4. Cavity. 5. Valve spool. 10. Spring. 11. Chamber. 14. Slug. 16. Passage. 17. Outlet port. 18. Cavity. 19. Valve spool. 21. Spring. 22. Plunger.

NOTE: Passages (3) and (16) in valve spools (5) and (19) are open to outlet ports (2) and (17) regardless of


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the position of valve spools. Thus, the amount of oil pressure behind the clutch control pistons, is always sensed in cavities (4) and (18). See Fig. 3. When the right steering clutch control lever is pulled all the way back to disengage the right steering clutch, plunger (22) is moved to the rear exerting a force on spring (21). This in turn forces valve spool (19) to the rear until it contacts plug (13). The plunger continues to move to the rear, compressing the spring, until the shoulder in the spring bore contacts washer (20). The plunger is then bottomed against the shoulder in the valve spool housing. Outlet port (17) is then open to chamber (11) and the maximum oil pressure in the system is acting on the right steering clutch control piston, compressing the clutch springs and releasing the right steering clutch. In this position, there is no pressure modulating action of valve spool (19) as plunger (22) is in direct contact with the valve spool.

FIG. 3. FLOW OF OIL - SCHEMATIC Left Clutch ENGAGED, Right Clutch Fully Released 11. Chamber. 13. Plug. 17. Outlet port. 19. Valve spool. 20. Washer. 21. Spring. 22. Plunger.

When the right steering clutch lever is moved to engage the right steering clutch, the oil pressure in cavity (18) [created by the compression of the clutch springs in the right steering clutch] and force of springs (10) and (21), returns the plunger (22) and valve spool (19) to their neutral position. See Fig. 1. This allows the oil behind the steering clutch control piston to return to the sump through standpipe (8). The oil flow to disengage the left steering clutch is the same as described for the right steering clutch.

Brakes And Brake Control Linkage

BRAKE AND BRAKE CONTROL LINKAGE 1. Lock pawl. 2. Parking brake linkage. 3. Ratchet. 4. Parking brake lever. 5. Pedal. 6. Shaft. 7. Control lever. 8. Spring. 9. Control


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linkage. 10. Lever. 11. Link. 12. Lever shaft. 13. Strut support lever assembly. 14. Strut. 15. Toggle link. 16. Lever shaft. 17. Lever assembly. 18. Band.

Two contracting-band-type brakes, which operate independently of one another, are used to supplement the action of the steering clutch or to stop the tractor. Either or both brakes can be held in the locked position by the brake lock pawls (1). These pawls are actuated by a single hand lever. The operation of both brakes is the same. When pedal (5) is depressed, control linkage (9) moves control lever (7) forward. Shaft (6) and lever (10) rotate and pull up on link (11). This flattens toggle links (15) and causes strut support lever assembly (13) and lever assembly (17) to rotate about lever shafts (12) and (16). Struts (14) are forced against lugs on band (18), causing band to contract on drum. When pedal is released, spring (8) returns pedal, linkage and brake band to brake released position. The parking brake is engaged by depressing either or both pedals and pushing parking brake lever (4) down. This moves parking brake linkage (2) forward, engaging pawl (1) with ratchet (3). The brakes are held in applied position by the pawls that hold linkage in engaged position.

Undercarriage

TRACK ROLLER FRAME GROUP 1. Sprocket. 2. Recoil spring (beneath cover). 3. Track adjuster (beneath cover). 4. Track carrier roller. 5. Front idler. 6. Track. 7. Track rollers. 8. Track roller frame.

The undercarriage connects to the chassis and final drive to support machine weight and provide mobility. Two separate track assemblies are maintained in parallel alignment by the diagonal braces, but are free to oscillate independently. Track carrier rollers support the track between sprocket and idler. Front idlers guide the track. Track rollers ride the rails formed by the track links and distribute the weight of the machine along the track. Front idlers, track rollers and track carrier rollers use Duo-Cone floating seals to retain lubricant and keep out dirt. The machine is equipped with hydraulic track adjusters.

Track Roller Frame


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The track roller frames attach to the final drive shafts and to the steering clutch and bevel gear case. The roller frames are held parallel by the diagonal braces, but move independently. Mounted on the roller frames are the front idlers, track and track carrier rollers, recoil springs, track adjusters, and final drive supports. Alignment of roller frame and final drive is controlled by shim adjustment of the final drive supports.

Track Carrier Rollers The track carrier rollers support the track between the sprocket and the front idler. The carrier roller shaft is secured in the roller support bracket by a split clamp. The support bracket is bolted to the roller frame.

TRACK CARRIER ROLLER (9S2730) 1. Shaft. 2. Duo-Cone seal. 3. Roller bearings. 4. Plug. 5. End collar. 6. Carrier roller. 7. End cover.

Alignment of the carrier rollers with the sprocket and idler can be accomplished by in-and-out adjustment of the roller shaft in the support bracket. Carrier rollers turn on two tapered roller bearings.

Track Carrier Roller Lubrication The plug (6) is replaced by the 5M2080 Nozzle and lubricant is forced into the center passage (4). The lubricant fills the cavity between shaft and roller up to plug level. During filling, air is forced out through nozzle relief threads. When lubricant, free of air, flows out at the nozzle relief, remove the nozzle and install the plug (6). Tighten the plug to 125 ± 15. lb. ft. (17.3 ± 2.1 mkg).


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TRACK CARRIER ROLLER (9S2730) 1. Shaft. 2. Duo-Cone seal. 3. Bearings. 4. Passage. 5. End cover. 6. Plug.

If track carrier rollers are lubricated off the machine, the shaft must be in a horizontal position to assure proper lubricant level.

TRACK CARRIER ROLLER (5M7318) 6. Plug. 7. Adjustment nut.

Track Rollers Track rollers distribute the weight of the machine along the rails formed by the track links. A double flange roller follows the front idler. Next is a single flange roller followed by a double, a single, a double, and a single flange roller in front of the sprocket. The roller shafts ride on center thrust bearings. The center flange of the roller shaft takes the side thrust of the roller. Side movement or end clearance of the shaft is not adjustable.


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TRACK ROLLER 1. Lock. 2. Inner end collar. 3. Bearings. 4. Outer end collar. 5. Shaft. 6. Duo-Cone seals. 7. Track roller.

Track Roller Lubrication Lubricant is forced into the center passage through a 5M2080 Nozzle threaded into the shaft in place of the plug (3). The lubricant fills the reservoirs and forces air and lubricant out through nozzle relief threads.

TRACK ROLLER 1. Shaft. 2. Duo-Cone seals. 3. Plug. 4. Reservoirs. 5. Passage.

When lubricant is free of air bubbles, remove the nozzle and install the plug. Tighten the plug to 125 ± 15 lb. ft. (17.3 ± 2.1 mkg). If the track rollers are lubricated off the machine, the shaft must be in a horizontal position. Rollers with a flat surface on one side of the shaft must have the flat surface facing upward. Rollers with completely round shafts have a slot in one end which must be positioned downward.


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Front Idler The front idlers guide the track into position in front of the track rollers. Each idler rotates on a hardened shaft (9) and center thrust bearings (3). The center flange of the shaft takes the side thrust of the idler (8). Side movement or end clearance of the shaft is not adjustable. The ends of the idler shafts are secured in bearing assemblies (4) supported by plate assemblies (6). Springs in the bearing assemblies force the plates down against the tops of the track roller frames (10). The idler can be placed in a HIGH or LOW position. The high position is recommended for drawbar work and the low position for using front-mounted equipment. Alignment of front idler with the track rollers is accomplished with shims (5) between the bearing assemblies and outer plates (7).

FRONT IDLER 1. Fill plug. 2. Duo-Cone seal. 3. Bearing.s. 4. Bearing. 5. Shims. 6. Plate. 7. Outer plate. 8. Idler. 9. Shaft. 10. Track roller frame.

Front Idler Lubrication The front idler must be lubricated with the idler shaft in its LOW position. In machines where shaft positioning is possible, this may require unbolting the idler end bearing from the yoke and rotating the bearings 180° before lubrication. This should place the narrow portion of the bearing down and the idler shaft in the LOW position. The plug (1) is replaced by a 5M2080 Nozzle and lubricant is forced into the center passage. The lubricant fills the cavities around the shaft, and lubricant and air is forced out through relief threads in the nozzle. When lubricant is free of air, remove the nozzle and install the plug. Tighten the plug to 125 ± 15 lb. ft. (17.3 ± 2.1 mkg).


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FRONT IDLER 1. Plug. 2. End bearing. 3. Center passage. 4. Shaft. 5. Duo-Cone seals.

If the front idler is lubricated off the machine, be sure the shaft is in a horizontal position and the narrow portion of the end bearings is down.

Recoil Spring And Track Adjusting Mechanisms The recoil spring is normally compressed and held between a bracket and stops on the track roller frame and does not exert pressure against the track. If objects become caught between the track and rollers, idler or sprocket, the front idler will move to the rear and compress the recoil spring. This prevents the track from being overstressed. Compression of the recoil spring is limited by the sleeve on the recoil spring bolt. A recoil spring nut may be used to retain spring compression if spring assembly is to be removed. The nut has no other purpose. For proper machine operation, the recoil spring nut must be positioned and locked so that the end of the recoil spring nut extends .062 in. (1.57 mm) beyond the end of the recoil spring rod. The recoil spring nut is then locked by tightening the bolt in the end of the recoil spring rod.

Hydraulic-Type Track Adjuster Forward track adjustment is obtained by forcing lubricant into the cavity of the track adjuster cylinder. This moves the recoil rod and front idler forward, tightening the track. Hydraulic pressure can be relieved by opening the relief valve.


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HYDRAULIC TRACK ADJUSTER 1. Recoil spring stud nut. 2. Recoil spring. 3. Recoil spring stud. 4. Sleeve. 5. Track adjusting cylinder. 6. Front pilot. 7. Cavity. 8. Front idler recoil rod. 9. Track adjusting piston. 10. Stops (two).

Track The track link assembly has links, pins, seal washers and bushings. Each track link fits over the track link in front of it, making a chain. Each link has a counterbore in the part that fits over the other link. The seal washers between the counterbore and the bushings give a tight sealed fit to keep foreign materials out. Track pins and bushings are all similar.

Earlier Track All track bushings are the same length, except the master bushings which are shorter. Master pins can be identified by an indentation in the end.

TRACK LINK AND PINS 1. Spacer. 2. Master pin. 3. Coned disc seal washers. 4. Master bushing. 5. Track bushing. 6. Link. 7. Track pin. 8. Coned disc s eal washers.

Later Track The two piece master links (7) and master shoe (5) are held together with bolts (6).


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