992G Torqon Troubleshot

992G Wheel Loader AZX00001-UP (MACHINE) POWERED BY 3508B Engine(SEBP4013 - 47) - Documentation

Welcome: j210bat Product: WHEEL LOADER Model: 992 G WHEEL WHEEL LOADER LOADER AZX Co nfigurati nfiguration: on: 9 92G Wheel Loader AZX00001 -UP (MACHINE) POWERED BY BY 350 8B Engine Engine

Troubleshooting 992G Wheel Loader and 854G Wheel Dozer Power Train Media Number -SENR 1 3 47-08

Publication Date -0 1/07/20 1 2

Date Updated -24 /07 /2 01 2

i02775019

Torque Converter Troubleshooting SMCS - 3101-035

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Illustration 1 Schematic for the transmission hydraulic control (1) Number 2 clutch solenoid (2) Number 3 clutch solenoid (3) Priority valve (4) Number 1 clutch solenoid (5) Number 5 clutch solenoid

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(6) Number 4 clutch solenoid (7) Flow control orifice (8) Lockup clutch solenoid valve (if equipped) (9) Impeller clutch solenoid valve (10) Slug (11) Torque converter inlet ratio valve (12) Slug (13) Modulating relief valve (14) Direction selection spool (15) Torque converter (16) Lockup clutch (if equipped) (17) Impeller clutch (18) Selector spool for first speed and for third speed (19) Pressure differential valve (20) Load piston (21) Flow control orifice (22) Selector spool for second speed (23) Transmission oil filter (24) Transmission oil filter (25) Flow control orifice (26) Oil pump (27) Torque converter outlet relief valve (28) Oil cooler (29) Magnetic Screen (30) Lubrication passage for transmission (31) Reservoir (32) Reservoir (A) Oil pump output pressure tap (B) Pump pressure tap (C) Pressure tap for lockup clutch (if equipped) (D) Inlet pressure tap for the torque converter P3 (E) Speed clutch pressure tap P1 (F) Pressure tap for impeller clutch (G) Direction clutch pressure tap P2 (H) Pump pressure tap

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(I) Torque converter outlet pressure tap (J) Transmission lubrication pressure tap

Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine.

Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak.

NOTICE Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Dealer Service

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Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates.

Operational Checks Note: Operate the machine in each direction and in all speeds. Note the noises that are not normal and find the sources of the noises. If the machine is not operating correctly, refer to the "Troubleshooting Problem List" below.

Troubleshooting Problem List Torque converter pressure is high. Torque converter pressure is low. The torque converter overheats. The torque converter does not respond correctly for the left service brake pedal. The lockup clutch does not engage. The lockup clutch engages intermittently. The impeller clutch does not engage.

Troubleshooting Note: In the following section, when components are referenced with a number, refer to the schematic in 1.

Use the built-in electrical diagnostics that are performed with the Vital Information Management System (VIMS) or Vital Information Display System (VIDS) and with the electronic control module in order to determine the service codes for the power train electronic control module. Note: This machine is equipped with a power train electronic control. The power train electronic control has built-in system diagnostics that detect faults in the electronic system of the power tr ain. ReferenceFor additional information on the operation of the power train electronic control module (ECM) and troubleshooting the power train ECM, refer to the Service Manual module for Systems Operation, Testing and Adjusting, "Power Train Electronic Control System" f or the machine that is being serviced. ReferenceFor additional information on troubleshooting the power train electronic control module (ECM), refer to the Service Manual Module Systems Operation, Testing and Adjusting, SENR6059, "Vital Information Management System (VIMS)" or Systems Operation, Testing and Adjusting, RENR6318, "Vital Information Management System (VIMS)" for VIMS diagnostic procedures. ReferenceFor additional information on troubleshooting the power train electronic control module (ECM), refer to the Service Manual Module Service Manual, SENR1371, "Vital Information Display

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System (VIDS)" for VIDS diagnostic procedures.

Probable Causes of Problems in the Torque Converter Torque converter pressure is high Probable causes

1. There is a restriction inside the torque converter. 2. There is a restriction in an oil passage or in the oil cooler. 3. Torque converter inlet ratio valve (11) is stuck in the closed position.

Torque converter pressure is low Probable causes

1. Torque converter inlet ratio valve (11) is stuck in the open position. 2. Adjustment of torque converter outlet relief valve (27) is not correct. 3. The valve spool in torque converter outlet relief valve (27) does not move. 4. Pump flow or oil pressure is low. This may be caused by any of the following conditions: a. The oil level is low. b. There is a restriction in the oil flow circuit or a dirty oil strainer. c. Oil pump failure. d. Air leaks on the inlet side of the pump. e. Leakage inside the transmission (worn seals around the clutch piston) f. Modulating relief valve (13) is stuck open.

The torque converter overheats Probable causes

1. The machine is being used for the wrong application. There is too much torque converter slip, which is caused by too much load. 2. Incorrect transmission gear is being used for the load that is on the machine. Shift to a lower gear. 3. The oil level in the transfer gear case is incorrectly high or low. 4. The coolant level in the engine radiator is low. 5. The oil cooler or oil lines are restricted.

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6. Oil flow through the torque converter is too low. This may be caused by any of the following conditions: a. The torque converter inlet ratio valve (11) is bypassing too much oil flow. b. Pump flow or oil pressure is low. Refer to the Problem: Torque converter pressure is low.

The torque converter does not respond correctly to the left service brake pedal Probable causes

1. The torque converter is in the mode for reduced rimpull (if equipped). This changes the response of the left service brake pedal. 2. The sensor for the left service brake pedal is calibrated incorrectly. 3. The left service brake pedal position sensor is faulty. 4. The impeller clutch solenoid or the impeller clutch solenoid valve is faulty. 5. There is a problem in the electrical circuit.

The lockup clutch does not engage Probable causes

1. The on/off switch for the lockup clutch is not in the ON position. 2. The on/off switch for the lockup clutch is faulty. 3. The lockup clutch solenoid or the lockup clutch solenoid valve is faulty. 4. There is a problem in the electrical circuit.

The lockup clutch engages intermittently. Probable causes

1. Erratic signals from the engine speed sensor or the torque converter speed sensor can cause the lockup clutch in the torque converter to cycle on and off when the lockup clutch is enabled.

The impeller clutch does not engage Probable causes

1. The impeller clutch solenoid or the impeller clutch solenoid valve is faulty. 2. There is a problem in the electrical circuit.

Troubleshooting the Calibration of the Impeller Clutch

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The calibration of the impeller clutch can generate error messages if a problem is encountered during calibration. The following information is used to aid in troubleshooting the problem that was based on the error message. Table 1 Troubleshooting Information for the Calibration of the Impeller Clutch Error Message

Torque converter output speed is low.

Probable Causes

Engine speed is too low.

Use the throttle lock to set the engine speed above the following minimum values: 2050 rpm ( 988G, 834G, 836G) 1650 rpm (992G,994D,854G)

Speed sensor problem

Check for fault codes on the torque converter output speed sensor. Check the sensor connector. Adjust or replace the sensor, if necessary.

Check valve function. Check the connector. Impeller clutch pressure Check ECM output. is too low. Check the converter for excessive leakage in the circuit for the impeller clutch. Damaged impeller clutch

Check transmission screens. Inspect the impeller clutch.

Excessive drag in transmission

Check transmission screens. Inspect the impeller clutch.

Speed sensor problem Torque converter output speed is high. Engine speed is too high.

Speed sensor problem

The speed change of the torque converter is in the low range.

Check for fault codes on the torque converter output speed sensor. Check the sensor connector. Adjust or replace the sensor, if necessary. Adjust the engine high idle speed. Check for fault codes on the torque converter output speed sensor Check the sensor connector. Adjust or replace the sensor, if necessary.

Check valve function. Check the solenoid connector. Impeller clutch pressure Check ECM output. is too low. Check the converter for excessive leakage in the circuit for the impeller clutch.

Drag in the lockup clutch.

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Possible Corrective Actions

Check for residual pressure in the circuit for the lockup clutch. Check the screens in the transmission for material from the clutch.


Inspect the lockup clutch for damaged discs or damaged plates. If the lockup clutch has new discs, operate the machine and engage the lockup clutch several times. Repeat the calibration.

Excessive drag in the transmission

Holding pressure is too high.

Check valve function. Check the solenoid connector. Check the ECM output. Check the converter for excessive leakage in the Impeller clutch pressure circuit of the impeller clutch. is out of tolerance. Check for high torque converter inlet pressures and outlet pressures. Check the PTO system which is downstream of the converter for restrictions.

Holding pressure is too low.

Check valve function. Impeller clutch pressure Check the solenoid connector. is out of tolerance. Check ECM output.

Holding pressure inconsistent

Check valve function. Check the solenoid connector. Impeller clutch pressure Check ECM output. is not responding Check the converter for excessive leakage in the properly. circuit of the impeller clutch. Check the transmission screens for debris.

Copyright 199 3 - 201 4 Cat erpillar Inc. All Rights Reserved. Private Netw ork F or SIS Licensees.

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Check the screens in the transmission for material from the clutch. Inspect the transmission for warped direction clutches or damaged direction clutches.

Fri May 09 2014 10:26:59 GMT+0700 (SE Asia Standard Time) j210 bat

992G Torqon Troubleshot

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