722.9 Automatic Transmission722.9 Automatic Transmission
Tech 331, 722.9 (F,hayward),1/27/04
ObjectivesObjectives
? To know the advantages and Features of the
722.9 transmission
? To identify new components
? To understand maintenance concerns
? To know location / function of major components
? To explain shift members
? To explain electronics
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Features 722.9Features 722.9
h Electronically controlled 7-speed
h Seven forward and two reverse gears
h Fully integrated transmission control unit (Flash capable)
h Torque converter operates in open or slip mode in all seven forward gears
h Gear ratios are achieved with four multi disc brakes and three multi disc clutches (no free-wheeling units)
h 2 simple and 1 ravigneaux gear set
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AdvantagesAdvantages? Improved shift comfort/driving pleasure
q Quicker shifts 0.1 – 2.5 seconds
q 37 to 74 mph times shortened by between 23% and 28%
? Reduce fuel consumption (up to 4%)
? Reduce maintenance cost
h Increased service life and reliability
h Flexible adaptation to vehicle and engine
h Driver can choose between “S” and “C” mode4
Transmission DesignationTransmission DesignationTransmission722. 9 01
Version, e.g. matching to the respective engine
Sales designation
Automatic transmission for passenger cars
Sales DesignationW 7 A 700
Max. input torque in NM
Version (internal)
Number of forward gears
Hydraulic torque converter
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Transmission FluidTransmission Fluid
? The 722.9 transmission requires a newly developed transmission
fluid. MB part number A001 989 45 03
q Higher friction constancy
q Higher thermal stability
q Improved temperature behavior
q Lifetime fill
? Can be used in 722.3 / .4 / .5 / .6
? Must be used in 722.9
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Major Components (7 GMajor Components (7 G--Tronic)Tronic)
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Major Components LegendMajor Components Legend
1. Park pawl gear2. Turbine wheel3. Stator4. Impeller5. Transmission housing ventilation6. Oil pump7. B1 multi-disk brake8. K1 multi-disk clutch9. Ravigneaux gear set10. B3 multi-disk brake11. K2 multi-disk clutch12a. Front simple planetary gear set12b. Rear simple planetary gear set
13. BR multi-disk brake14. K3 multi-disk clutch15. B2 multi-disk brake16. Torque converter lockup clutch17. Torque converter housing18. Exciter ring for torque measurement19. Ring magnet for torque measurement20. Ring magnet for torque measurement21. Electro hydraulic control unit22. Range selector lever
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Transmission HousingTransmission Housing
• Magnesium housing (lighter weight) requires aluminum boltsany aluminum bolt must be replaced if removed!
• No power tools
• Adhere to angle torques9
Ravigneaux Gear SetRavigneaux Gear Set
1. Short planetary gear2. Long planetary gear3. Sun gear4. Planetary gear carrier
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
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MultiMulti--disk Clutch/Brakedisk 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. Friction lining on one side of metal carrierA. Metal carrier outer diskB. Metal carrier inner disk
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Fully Integrated Transmission Fully Integrated Transmission ControlControl
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Fully Integrated Transmission Fully Integrated Transmission Control LegendControl Legend
11 Plug connection21b Valve body21c Intermediate panel21d Shift housing31 Float 132 Float 2Y3/8 Electric control module Y3/8n1 Turbine rpm sensor Y3/8n2 Internal rpm sensor Y3/8n3 Output rpm sensor Y3/8n4 Transmission control
unitY3/8s1 Selection range sensor
Y3/8y1 Working pressure control solenoid valve Y3/8y2 K1 clutch control solenoid valve Y3/8y3 K2 clutch control solenoid valve Y3/8y4 K3 clutch control solenoid valve Y3/8y5 B1 brake control solenoid valve Y3/8y6 B2 brake control solenoid valve Y3/8y7 B3 brake control solenoid valve Y3/8y8 Torque converter lockup clutch
control solenoid valve
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Electronic Transmission Control Electronic Transmission Control Unit InputsUnit 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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Internal inputs effecting solenoid valves
• Turbine rpm sensor (active)
• Internal rpm sensor (active)
• Output rpm sensor (hall)
• Transmission oil temperature sensor
Electronic Transmission Control Electronic Transmission Control Unit InputsUnit Inputs
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Electronic Transmission Control Electronic Transmission Control UnitUnit
• 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 16
Electronic Transmission Control Electronic Transmission Control Unit FunctionsUnit 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 andpressure
• Driver actions; accelerator movement, manualtouch frequency, longitudinal and lateralacceleration
• Software can be updated, referred to as flashing, carried out using SDS
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Speed Sensor LocationsSpeed Sensor Locations
Y3/8n1 Turbine rpm sensorY3/8n2 Internal rpm sensorY3/8n3 Output rpm sensor
1. Ring magnet2. Cylinder flange with
integrated ring magnet3. Exciter ring4a. Park pawl gear
• Turbine speed sensor monitorsrotational speed of internalravigneaux gear
• Internal speed sensor measuresrotational speed front planetary gear
• Output speed sensor measurestransmission output speed parkpawl
• Output speed sensor increasesreaction time
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Shift ProgramShift Program
Basic shift program can be influenced using selector buttonon 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-Cto ETC
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Shift ProgramsShift 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
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Shifting ProcessShifting 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 increasein shift quality
• Main function of ETC is to evaluate inputs relevant to transmissionfunction and actuate eight hydraulic valves, which set working pressure
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Solenoid ValvesSolenoid ValvesInternal output signal or actuation ofcontrol 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 allowspressure
• B2 brake valve (Y3/8y6)normally closed in default no pressure
Y3/8y8 – Torque converter lockup clutch valveY3/8y1 – Working pressure valveY3/8y3 – K2 clutch valveY3/8y6 – B2 brake valve
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Solenoid ValvesSolenoid Valves
Internal output signal or actuation ofcontrol solenoid valves
• K1 clutch valve (Y3/8y2)normally open in default allowspressure
• B1 brake valve (Y3/8y5)normally open in default allowspressure
• B3 brake valve (Y3/8y7)normally closed in default nopressure
• K3 clutch valve (Y3/8y4)normally open in default allowspressure
Y3/8y2 – K1 clutch valveY3/8y5 – B1 brake valveY3/8y7 – B3 brake valveY3/8y4 – K3 clutch valve
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722.9722.9Down ShiftingDown Shifting
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Shift ChartShift Chart
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7
6
5
4
3
2
1
Release B3
Apply B1 Release B1
Apply K1 Release K3
Apply B2 Release K2
Apply K3 Release K1
Apply B1 Release B1
Apply B326
7
6
5
4
3
2
1
Release B3
Apply K1
Release K2
Apply B2
Release K1
Apply B3
Release K2
Apply B2
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Emergency FunctionEmergency Function
• To guarantee safe driving and prevent damage ETC switches to emergency modeon 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 lubricationpressure
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Special ToolsSpecial Tools
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Process Overview for Repair WorkProcess 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 EDACDiagnostics Via EDAC
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Service Advisors Checklist must be filled out before repair attempt
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Diagnostics Via EDACDiagnostics Via EDAC
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Information Needed for WarrantyInformation Needed for Warranty
? From Transmission Control Unitq Control Unit Versionq Fault Codesq Freeze Frame Dataq Read Coding Page in Control Unit Adaptions Menu
? From ESM Control Unitq Control Unit Versionq Fault Codes
? Must be original printouts!q Photocopies will not be acceptedq Do not erase fault codes
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Transmission Oil PanTransmission Oil Pan
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Note: new oil pan soon available requires slightly different procedure for fillingTemp. must be 40 to 45°C when checking level
Prototype 7 GPrototype 7 G--Tronic Filling Tronic Filling StationStation
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Key Function Of Filling StationKey Function Of Filling Station
iProvide an accurate method to fill 722.9 after service has beenperformed that will still be time and cost effective
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Unit Operation Unit Operation Preliminary InstructionsPreliminary Instructions
• Raise vehicle and remove drain plug
• Use caution as some fluid will spill, the converter drains back with engineshut 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) 42
Unit Operation Unit Operation Preliminary InstructionsPreliminary 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 Unit Operation Preliminary InstructionsPreliminary Instructions
i Check fluid level in fresh fluid tank there is a sight glass in lower cabinet rear
i Add new 722.9 fluid as necessary 30 liter max capacity
(replace cap on fresh fluid tank)
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Unit OperationUnit OperationPreliminary InstructionsPreliminary Instructions
Connect unit to shop air supply - (no min. max. spec at present)
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Unit OperationUnit OperationPreliminary InstructionsPreliminary Instructions
Turn main valve on front panel to pressure position46
Unit OperationUnit OperationPreliminary InstructionsPreliminary Instructions
Turn main valve on front panel to pressure position47
Unit OperationUnit OperationPreliminary InstructionsPreliminary Instructions
i Program dispenser handle to auto.set to number of liters desiredsqueeze handle and release, it willdispense automatically, you canstop flow by pressing the red button on the handle
i 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 POINTREFER TO WIS
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Unit OperationUnit OperationPreliminary InstructionsPreliminary Instructions
iConnect SDS / DAS to view actual values
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Unit OperationUnit OperationPreliminary InstructionsPreliminary Instructions
i Making certain no hoses are close to exhaust start and idle engine
i Shift through gear selections several times to purge any air fromhydraulic system
i Program remaining portion of new 722.9 fluid (4 liters for dry fill) at dispenser handle
i At approximately 30°C add remaining fluid
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i At 30 - 35°C place Y-valve to drain back (vertical position)
iTurn main valve to depressurize position on front panel
Unit OperationUnit OperationPreliminary InstructionsPreliminary Instructions
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• 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 anyother 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 panelsthat may have been removed during this service operation
Unit OperationUnit OperationPreliminary InstructionsPreliminary Instructions
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Questions
More to come53
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