722.9 Automatic Transmission
Tech 331, 722.9 (F,hayward),1/27/04
Objectives ?
To know the advantages and Features of the 722.9 transmission transmission
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To identify new components
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To understand maintenance concerns
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To know location / function of major components
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To explain shift members
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To explain electronics
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Features 722.9 h
Electronically controlled con trolled 7-speed
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Seven forward and two reverse gears
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Fully integrated transmission control unit (Flash capable)
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Torque converter operates in open or slip mode in all seven forward gears Gear ratios are achieved with four multi disc brakes and three multi disc clutches (no free-wheeling units) 2 simple and 1 ravigneaux gear set
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Advantages ?
Improved shift comfort/driving pleasure q
Quicker Quicker shifts shifts 0 0.1 .1 – 2.5 seconds seconds
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37 to 74 mph times shortened by between 23% and 28%
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Reduce fuel consumption (up to 4%)
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Reduce maintenance cost
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Increased service life and reliability
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Flexible adaptation to vehicle and engine
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Driver can choose between “S” and “C” mode 4
Transmission Designation Transmission 722 22.. 9 01 Version, e.g. matching to the respective engine Sales designation Automatic transmission for passenger cars
Sales Designation W 7 A 700 Max. input torque in NM Version (internal) Number of forward gears Hydraulic torque converter 5
Transmission Fluid ?
The 722.9 transmission requires a newly developed transmission fluid. MB part number A001 989 45 03 q
Higher friction constancy
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Higher thermal stability
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Improved temperature behavior
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Lifetime fill
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Can be used in 722.3 / .4 / .5 / .6
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Must be used in 722.9
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Major Components (7 G - -Tronic) T ronic)
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Major Components Legend 1. Park pawl gear 2. Turbine wheel 3. Stator 4. Impeller 5. Transmission housing ventilation 6. Oil pump 7. B1 multi-disk brake 8. K1 multi-disk clutch 9. Ravigneaux gear set 10. B3 multi-disk brake 11. K2 multi-disk clutch 12a. Front simple planetary gear set 12b. Rear simple planetary gear set
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14. 15. 16. 17. 18. 19. 20. 21. 22.
BR multi-disk brake K3 multi-disk clutch B2 multi-disk brake Torque converter lockup clutch Torque converter housing Exciter ring for torque measurement Ring magnet for torque measurement Ring magnet for torque measurement Electro hydraulic control unit Range selector lever
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Transmission Housing
• Magnesium housing (lighter weight) requires aluminum bolts any aluminum bolt must be replaced if removed! • No power tools • Adhere to angle torques 9
Ravigneaux Gear Set Advantages of ravigneaux gear set • Shifting under load • Production of several gear ratios • Constant engagement of gearing • Easier reversal of rotational direction • High efficiency • Compact construction • Combines 2 simple planetary gear sets into one unit
1. 2. 3. 4.
Short planetary gear Long planetary gear Sun gear Planetary gear carrier
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Multi - -disk d isk Clutch/Brake •
Transferable power of multi-disk clutch increased
• Friction disks of K1, K2 and K3 now have single-sided friction disks • Cost advantage • Less installation space required • Higher load capability • Lower mass
1. A. B.
Friction lining on one side of metal carrier Metal carrier outer disk Metal carrier inner disk
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Fully Integrated Transmission Control
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Fully Integrated Transmission Control Legend 11 21b 21c 21d 31 32 Y3/8 Y3/8n1 Y3/8n2 Y3/8n3 Y3/8n4
Plug connection Valve body Intermediate panel Shift housing Float 1 Float 2 Electric control module Turbine rpm sensor Internal rpm sensor Output rpm sensor Transmission control unit Y3/8s1 Selection range sensor
Y3/8y1 Y3/8y2 Y3/8y3 Y3/8y4 Y3/8y5 Y3/8y6 Y3/8y7 Y3/8y8
Working pressure control solenoid valve K1 clutch control solenoid valve K2 clutch control solenoid valve K3 clutch control solenoid valve B1 brake control solenoid valve B2 brake control solenoid valve B3 brake control solenoid valve Torque converter lockup clutch control solenoid valve
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Electronic Transmission Control Unit Inputs Monitors and shifts transmission based on: • Vehicle speed • Vehicle load • Accelerator position • Selector lever position • Electronic selector lever module (N15/5) • Transmission condition (aging)
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Electronic Transmission Control Unit Inputs Internal inputs effecting solenoid valves • Turbine rpm sensor (active) • Internal rpm sensor (active) • Output rpm sensor (hall) • Transmission oil temperature sensor
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Electronic Transmission Control Unit • Mounted directly on the hydraulic control unit • Married to vehicle – ETC unit calibrated to hydraulic control unit on flow bench • Information received over CAN with ME – Engine rpm, coolant temperature, accelerator position, engine load – ESP signals – Cruise control signals • Information received from ETC – Position of selector range valve – Transmission oil temperature – Transmission internal revolutions – Transmission output rpm
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Electronic Transmission Control Unit Functions From data received Transmission control unit calculates • Driver and vehicle specific shift points • Hydraulic pressures • Torque converter lockup clutch • Corrects for atmospheric pressure, shifting and pressure • Driver actions; accelerator movement, manual touch frequency, longitudinal and lateral acceleration • Software can be updated, referred to as flashing, carried out using SDS 17
Speed Sensor Locations • Turbine speed sensor monitors rotational speed of internal ravigneaux gear • Internal speed sensor measures rotational speed front planetary gear • Output speed sensor measures transmission output speed park pawl • Output speed sensor increases reaction time
1. Ring magnet 2. Cylinder flange with integrated ring magnet 3. Exciter ring 4a. Park pawl gear
Y3/8n1 Y3/8n2 Y3/8n3
Turbine rpm sensor Internal rpm sensor Output rpm sensor 18
Shift Program Basic shift program can be influenced using selector button on the electronic selector lever control module • Driver can choose transmission modes, “C” (comfort) or “S” (sport) • Each mode has different shift strategies • Transmission mode “S” (firmer faster shift) as opposed to mode “C” engine rpm level raised • Switch position transmitted by electronic selector module over CAN-C to ETC
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Shift Programs The adjustment of the shift programs takes place by moving the characteristic dependent on: • Vehicle payload • Change in engine load • Pedal movement • Slow
Unintended downshifts in high vehicle speed range are prevented
• Fast release
The up-shift to the next gear is prevented and is only allowed again at low lateral vehicle acceleration
• Kick-down
Bringing forward and raising of the downshift characteristic in the upper vehicle speed range 20
Shifting Process • ETC controls solenoid valves electronically • Valves sit in hydraulic shift plate • Shift plate implements hydraulic function • ETC precisely adjusts pressure during shift phase, which leads to increase in shift quality • Main function of ETC is to evaluate inputs relevant to transmission function and actuate eight hydraulic valves, which set working pressure
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Solenoid Valves Internal output signal or actuation of control solenoid valves • Torque converter lockup clutch valve (Y3/8y8) normally closed in default no pressure • Working pressure valve (Y3/8y1) normally open in default allows pressure • K2 clutch valve (Y3/8y3) normally open in default allows pressure • B2 brake valve (Y3/8y6) normally closed in default no pressure
Y3/8y8 – Torque converter lockup clutch valve Y3/8y1 – Working pressure valve Y3/8y3 – K2 clutch valve Y3/8y6 – B2 brake valve
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Solenoid Valves Internal output signal or actuation of control solenoid valves • K1 clutch valve (Y3/8y2) normally open in default allows pressure • B1 brake valve (Y3/8y5) normally open in default allows pressure • B3 brake valve (Y3/8y7) normally closed in default no pressure • K3 clutch valve (Y3/8y4) normally open in default allows pressure
Y3/8y2 Y3/8y5 Y3/8y7 Y3/8y4
– K1 clutch valve – B1 brake valve – B3 brake valve – K3 clutch valve
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722.9 Down Shifting
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Shift Chart
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Release B3
Apply B1
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Release B1
Apply K1
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Release K3
Apply B2
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Apply K3
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Release K1
Apply B1
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Release B1
Apply B3
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Release K2
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Release B3
7 6
Apply K1 Release K2
Release K2
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Apply B2 Release K1
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Apply B3
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Apply B2
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Emergency Function • To guarantee safe driving and prevent damage ETC switches to emergency mode on critical faults • Electric fault, all control solenoid valves switched off, transmission enters emergency mode defaults to 6th gear • After engaging “P”, “D” provides 2nd gear and reverse • Hydraulic faults engaged gear is kept • Solenoid valve faults effected gear is blocked no longer actuated • Flat bed transportation recommended (vehicle not drive-able) If towing must be performed max. towing speed 31 mph max. distance 31 miles, no lubrication pressure
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Special Tools
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Process Overview for Repair Work Dealer verifies customer report related to Transmission Diagnose condition via Diagnosis Guide posted on STAR Tekinfo website Dealer contacts EDAC if it is determined that there is an actual issue requiring assistance EDAC reviews diagnosis including completeness of MBUSA provided diagnostic information EDAC Authorized replacement of necessary components Dealer returns authorized component with EDAC authorization number referenced in the DTC field of the warranty claim or handling fee will be debited
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Diagnostics Via EDAC
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Service Advisors Checklist must be filled out before repair attempt
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Diagnostics Via EDAC
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Information Needed for Warranty ?
From Transmission Control Unit q
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From ESM Control Unit q
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Control Unit Version Fault Codes Freeze Frame Data Read Coding Page in Control Unit Adaptions Menu
Control Unit Version Fault Codes
Must be original printouts! q
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Photocopies will not be accepted Do not erase fault codes
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Transmission Oil Pan
Note: new oil pan soon available requires slightly different procedure for filling Temp. must be 40 to 45°C when checking level 39
Prototype 7 G - -Tronic T ronic Filling Station
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Key Function Of Filling Station Provide an accurate method to fill 722.9 after service has been performed that will still be time and cost effective
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Unit Operation Preliminary Instructions • Raise vehicle and remove drain plug • Use caution as some fluid will spill, the converter drains back with engine shut off •
Using special tool no. 722-589-03-15-00 remove plastic pipe • if replacing transmission discard old fluid • if servicing transmission save and measure fluid content for refill
• Remove six aluminum torque to yield screws part no. A 004-990-35-12 and discard, New screws must be used! • Remove pan inspect and clean • Replace plastic overflow pipe onto pan • Install pan using six new aluminum torque to yield screws • Torque to 4nm. + 180° (See WIS)
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Unit Operation Preliminary Instructions •
Screw adapter interface fitting part no. ??? into pan drain / fill port
• Attach Y - valve and manifold to interface adapter (valve handle in horizontal position)
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Unit Operation Preliminary Instructions i
Check fluid level in fresh fluid tank there is a sight glass in lower cabinet rear
Add new 722.9 fluid as necessary 30 liter max capacity (replace cap on fresh fluid tank) i
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Unit Operation Preliminary Instructions
Connect unit to shop air supply - (no min. max. spec at present) 45
Unit Operation Preliminary Instructions
Turn main valve on front panel to pressure position 46
Unit Operation Preliminary Instructions
Turn main valve on front panel to pressure position 47
Unit Operation Preliminary Instructions i
Program dispenser handle to auto. set to number of liters desired squeeze handle and release, it will dispense automatically, you can stop flow by pressing the red button on the handle
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You can also dispense manually by simply squeezing the handle, Batch will count up on LCD useful for service refill - top off the fill
NEW UNIT DRY FILL = 6 LITERS AT THIS POINT REFER TO WIS 48
Unit Operation Preliminary Instructions Connect SDS / DAS to view actual values
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Unit Operation Preliminary Instructions i
Making certain no hoses are close to exhaust start and idle engine
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Shift through gear selections several times to purge any air from hydraulic system
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Program remaining portion of new 722.9 fluid (4 liters for dry fill) at dispenser handle At approximately 30°C add remaining fluid
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Unit Operation Preliminary Instructions i
At 30 - 35°C place Y-valve to drain back (vertical position)
Turn main valve to depressurize position on front panel
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Unit Operation Preliminary Instructions • As drain back stops at 35°C remove Y-valve and interface adapter fitting from pan
• Fluid level is now correct performing this operation at any other temperature will result in an incorrect fluid level • Install drain / fill plug • Wipe any residual fluid from pan • Check for leaks • Replace any brackets and or under body encapsulation panels that may have been removed during this service operation
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