Chrysler 42LE Automatic Transmission Service & Repair Manual

42LE TRANSAXLE TABLE OF CONTENTS page page DESCRIPTION AND OPERATION 42LE TRANSAXLE ........................ 2 FLUID REQUIREMENT ..................... 4 TORQUE CONVERTER ..................... 4 OIL PUMP............................... 5 VALVE BODY............................. 6 ACCUMULATORS ......................... 7 INPUT CLUTCHES ........................ 8 HOLDING CLUTCHES ...................... 9 PLANETARY GEARTRAIN .................. 10 DIFFERENTIAL .......................... 10 TRANSMISSION CONTROL MODULE ........ 10 TRANSMISSION CONTROL RELAY .......... 13 SOLENOID/PRESSURE SWITCH ASSEMBLY . . . 14 TRANSMISSION RANGE SENSOR ........... 15 SHIFT POSITION INDICATOR ............... 16 INPUT SPEED SENSOR ................... 16 OUTPUT SPEED SENSOR.................. 17 BRAKE TRANSMISSION SHIFT INTERLOCK SYSTEM (FLOOR SHIFT) ................. 18 BRAKE TRANSMISSION SHIFT INTERLOCK SYSTEM (COLUMN SHIFT) ............... 18 AUTOSTICK............................. 19 DIAGNOSIS AND TESTING 42LE GENERAL DIAGNOSIS................ 20 ROAD TEST ............................ 20 HYDRAULIC PRESSURE TESTS ............. 21 CLUTCH AIR PRESSURE TESTS ............ 23 FLUID LEAKAGE ......................... 24 FLUID LEAKAGE-TORQUE CONVERTER HOUSING AREA ........................ 25 BRAKE/TRANSMISSION SHIFT INTERLOCK SYSTEM (COLUMN SHIFT) ............... 26 BRAKE/TRANSMISSION SHIFT INTERLOCK SYSTEM (FLOOR SHIFT) ................. 27 SHIFT POSITION INDICATOR ............... 28 AUTOSTICK............................. 28 SERVICE PROCEDURES FLUID LEVEL AND CONDITION CHECK ....... 29 FLUID AND FILTER SERVICE— TRANSMISSION ....................... 29 FLUID DRAIN AND REFILL-DIFFERENTIAL SUMP ............................... 31 ALUMINUM THREAD REPAIR .............. 31 FLUSHING COOLERS AND TUBES ........... 31 OIL PUMP VOLUME CHECK................ 32 TRANSAXLE QUICK LEARN PROCEDURE ..... 33 PINION FACTOR PROCEDURE .............. 33 REMOVAL AND INSTALLATION GEARSHIFT CABLE–COLUMN SHIFT ......... 33 GEARSHIFT CABLE–FLOOR SHIFT ........... 36 FLOOR SHIFTER ......................... 38 INTERLOCK CASSETTE ................... 39 BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID (COLUMN) ................... 40 BRAKE/TRANSMISSION SHIFT INTERLOCK CABLE (FLOOR) ........................ 43 TRANSMISSION RANGE SENSOR ........... 45 INPUT SPEED SENSOR ................... 46 OUTPUT SPEED SENSOR.................. 46 TRANSMISSION CONTROL MODULE ........ 47 TRANSMISSION CONTROL RELAY .......... 48 SOLENOID/PRESSURE SWITCH ASSEMBLY . . . 48 VALVE BODY............................ 48 TRANSAXLE ............................ 50 OIL PUMP SEAL REPLACEMENT ............ 52 TRANSFER SHAFT SEAL REPLACEMENT ..... 53 LONG STUB SHAFT SEAL REPLACEMENT .... 54 SHORT STUB SHAFT SEAL REPLACEMENT . . . 55 DISASSEMBLY AND ASSEMBLY VALVE BODY............................ 57 TRANSAXLE—DISASSEMBLY .............. 65 OIL PUMP.............................. 83 INPUT CLUTCH ASSEMBLY ................ 84 TRANSAXLE—ASSEMBLY ................ 101 DIFFERENTIAL RECONDITION ............. 119 CLEANING AND INSPECTION TRANSFER CHAINS LENGTH MEASUREMENT ...................... 140 ADJUSTMENTS GEARSHIFT CABLE–COLUMN SHIFT ........ 141 GEARSHIFT CABLE–FLOOR SHIFT .......... 141 LH 42LE TRANSAXLE 21 - 1

BRAKE/TRANSMISSION SHIFT INTERLOCK (FLOOR) ............................. 142 AUTOSTICK............................ 143 BEARING ADJUSTMENT PROCEDURES ..... 143 MASTER SHIM CHART ................... 143 DRIVE SPROCKET HEIGHT ADJUSTMENT PROCEDURE ......................... 145 SCHEMATICS AND DIAGRAMS 42LE TRANSAXLE HYDRAULIC SCHEMATICS. 146 SPECIFICATIONS 42LE AUTOMATIC TRANSAXLE ............ 159 42LE TRANSAXLE TORQUE SPECIFICATIONS. 159 SPECIAL TOOLS 42LE AUTOMATIC TRANSAXLE ............ 160 DESCRIPTION AND OPERATION 42LE TRANSAXLE DESCRIPTION Fig. 1 42LE Transaxle 21 - 2 42LE TRANSAXLE LH

The 42LE (Fig. 1) is a four-speed transaxle that is a conventional hydraulic/mechanical assembly with an integral differential, and is controlled with adaptive electronic controls and monitors. The hydraulic system of the transaxle consists of the transaxle fluid, fluid passages, hydraulic valves, and various line pressure control components. An input clutch assembly which houses the underdrive, overdrive, and reverse clutches is used. It also utilizes separate holding clutches: 2nd/4th gear and Low/Reverse. The primary mechanical components of the transaxle con- sist of the following: • Three multiple disc input clutches • Two multiple disc holding clutches • Four hydraulic accumulators • Two planetary gear sets • Hydraulic oil pump • Valve body • Solenoid/Pressure switch assembly • Integral differential assembly Control of the transaxle is accomplished by fully adaptive electronics. Optimum shift scheduling is accomplished through continuous real-time sensor feedback information provided to the Transmission Control Module (TCM). The TCM is the heart of the electronic control system and relies on information from various direct and indirect inputs (sensors, switches, etc.) to deter- mine driver demand and vehicle operating conditions. With this information, the TCM can calculate and perform timely and quality shifts through various output or control devices (solenoid pack, transmission control relay, etc.). The TCM also performs certain self-diagnostic functions and provides comprehensive information (sensor data, DTC’s, etc.) which is helpful in proper diagnosis and repair. This information can be viewed with the DRB scan tool. TRANSAXLE IDENTIFICATION The 42LE transaxle identification code is a series of digits printed on a bar-code label that is fixed to the transaxle case as shown in (Fig. 2). For example, the identification code K 821 1125 1316 can be broken down as follows: • K = Kokomo Transmission Plant • 821 = Last three digits of the transaxle part number • 1125 = Build date • 1316 = Build sequence number If the tag is not legible or missing, the “PK” number, which is stamped into the transaxle case, can be referred to for identification. This number differs slightly in that it contains the entire transaxle part number, rather than the last three digits. OPERATION Transmission output is directed to an integral differential by a transfer gear system in the following input-to-output ratios: First .............................. 2.84 : 1 Second ............................. 1.57 : 1 Third .............................. 1.00 : 1 Overdrive .......................... 0.69 : 1 Reverse ............................ 2.21 : 1 1 – DIFFERENTIAL 2 – TRANSFER SHAFT 3 – TRANSFER GEAR 4 – FRONT PLANETARY CARRIER 5 – REAR PLANETARY CARRIER 6 – OUTPUT SHAFT 7 – OUTPUT GEAR 8 – OUTPUT SPEED SENSOR 9 – LOW/REVERSE CLUTCH 10 – 2/4 CLUTCH 11 – REVERSE CLUTCH 12 – OVERDRIVE CLUTCH 13 – UNDERDRIVE CLUTCH 14 – INPUT SPEED SENSOR 15 – CONVERTER CLUTCH 16 – OIL PUMP 17 – INPUT SHAFT 18 – TORQUE CONVERTER Fig. 2 Transaxle Identification Label 1 – INPUT SPEED SENSOR 2 – OUTPUT SPEED SENSOR 3 – IDENTIFICATION TAG LH 42LE TRANSAXLE 21 - 3 DESCRIPTION AND OPERATION (Continued)

FLUID REQUIREMENT NOTE: Refer to the maintenance schedules in Group 0, Lubrication and Maintenance for the rec- ommended maintenance (fluid/filter change) inter- vals for this transaxle. NOTE: Refer to Service Procedures in this group for fluid level checking procedures. NOTE: The 42LE transaxle has separate transmission and differential oil sumps, each requiring dif- ferent fluids. DESCRIPTION TRANSMISSION Mopart ATF+4 (Automatic Transmission Fluid- Type 9602) is required in this transaxle. Substitute fluids can induce torque converter clutch shudder. Mopart ATF+4 (Automatic Transmission Fluid- Type 9602) when new is red in color. TheATF is dyed red so it can be identified from other fluids used in the vehicle such as engine oil or antifreeze. The red color is not permanent and is not an indicator of fluid condition. As the vehicle is driven, the ATF will begin to look darker in color and may eventually become brown. This is normal. A dark brown/black fluid accompanied with a burnt odor and/or deterioration in shift quality may indicate fluid deterioration or transmission component failure. DIFFERENTIAL The differential sump should be filled with Mopart 75W-90 hypoid gear lubricant. Synthetic gear lubri- cants should be avoided. FLUID ADDITIVES DaimlerChrysler strongly recommends against the addition of any fluids to the transmission, other than those automatic transmission fluids listed above. Exceptions to this policy are the use of special dyes to aid in detecting fluid leaks. Various “special” additives and supplements exist that claim to improve shift feel and/or quality. These additives and others also claim to improve converter clutch operation and inhibit overheating, oxidation, varnish, and sludge. These claims have not been sup- ported to the satisfaction of DaimlerChrysler and these additives must not be used. The use of transmission “sealers” should also be avoided, since they may adversely affect the integrity of transmission seals. TORQUE CONVERTER DESCRIPTION The torque converter is located in the bellhousing area of the transaxle, between the engine and transaxle. The torque converter is a fluid coupling that transmits torque from the engine drive plate to the input shaft of the transaxle. The torque converter consists of four main components (Fig. 3) : • Impeller • Turbine • Stator • Converter Clutch assembly OPERATION The converter impeller (driving member), which is integral to the converter housing and bolted to the engine drive plate, rotates at engine speed. The converter turbine (driven member), which reacts from fluid pressure generated by the impeller, rotates and turns the transmission input shaft. Torque is transmitted by fluid passing through curved vanes in both the impeller and turbine. Since Fig. 3 Torque Converter Assembly 1 – TURBINE 2 – IMPELLER 3 – HUB 4 – STATOR 5 – CONVERTER CLUTCH DISC 6 – DRIVE PLATE 21 - 4 42LE TRANSAXLE LH DESCRIPTION AND OPERATION (Continued)

the coupling is produced by transmission fluid, the turbine can slip or turn slower than the impeller. The stator contains a one-way overrunning clutch, which free-wheels when the impeller and turbine are rotating at the same speed. However, the stator stops when speed reduction or torque increase take place. When the stator stops, it changes the direction of the fluid leaving the turbine vanes. This directs fluid back into the impeller with greater force, resulting in torque multiplication. The torque converter clutch is hydraulically oper- ated and controlled by the TCM. It consists of a pis- ton and a frictional disc that form a direct mechanical link between the impeller and turbine when slippage is inefficient or unnecessary. The torque converter hub drives the transmission oil pump. ELECTRONICALLY MODULATED CONVERTER CLUTCH In order to reduce heat build-up in the transmission and buffer the powertrain against torsional vibrations, the TCM can duty cycle the LR/CC solenoid to achieve a smooth application of the torque converter clutch. This function, also referred as “Electronically Modulated Converter Clutch (EMCC), can occur at various times depending on the following variables: • Shift lever position • Current gear range • Transmission fluid temperature • Engine coolant temperature • Input speed • Throttle angle • Engine speed The TCM controls the torque converter by way of internal logic software. The programming of the software provides the TCM with fine control over the LR/CC solenoid. There are four output logic states that can be applied as follows: • No EMCC • Partial EMCC • Full EMCC • Gradual-to-no EMCC NO EMCC Under No EMCC conditions, the L/R Solenoid is OFF. There are several conditions that can result in NO EMCC operations. No EMCC can be initiated due to a fault in the transaxle or because the TCM does not see the need for EMCC under current driving conditions. PARTIAL EMCC Partial EMCC operation modulates the L/R Sole- noid (duty cycle) to obtain partial torque converter clutch application. Partial EMCC operation is main- tained until Full EMCC is called for an actuated. During Partial EMCC some slip does occur. Partial EMCC will usually occur at low speeds, low load and light throttle situations. FULL EMCC During Full EMCC operation, the TCM increases the L/R Solenoid duty cycle to full ON after Partial EMCC control brings the engine speed within the desired slip range of transaxle input speed relative to engine rpm. GRADUAL-TO-NO EMCC This operation is to soften the change from Full or Partial EMCC to No EMCC. This is done at mid- throttle by decreasing the L/R Solenoid duty cycle. OIL PUMP DESCRIPTION The oil pump is located in the pump housing inside the bell housing of the transaxle case. The oil pump consists of an inner and outer gear, a housing, and a cover that also serves as the reaction shaft support. Fig. 4 Oil Pump Assembly 1 – PUMP HOUSING 2 – OUTER PUMP GEAR 3 – INNER PUMP GEAR 4 – REACTION SHAFT SUPPORT 5 – SEAL RINGS (4) 6 – REACTION SHAFT 7 – CRESCENT LH 42LE TRANSAXLE 21 - 5 DESCRIPTION AND OPERATION (Continued)

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Chrysler 42LE Automatic Transmission Service & Repair Manual

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