Jeep 42RLE Automatic Transmission Service & Repair Manual

AUTOMATIC TRANSMISSION - 42RLE TABLE OF CONTENTS page page AUTOMATIC TRANSMISSION - 42RLE DESCRIPTION ......................... 38 OPERATION ........................... 40 DIAGNOSIS AND TESTING DIAGNOSIS AND TESTING - AUTOMATIC TRANSMISSION ...................... 46 DIAGNOSIS AND TESTING - ROAD TEST . . . 46 DIAGNOSIS AND TESTING - HYDRAULIC PRESSURE TESTS .................... 47 DIAGNOSIS AND TESTING - CLUTCH AIR PRESSURE TESTS .................... 50 DIAGNOSIS AND TESTING - FLUID LEAKAGE ........................... 50 STANDARD PROCEDURE - ALUMINUM THREAD REPAIR ...................... 51 REMOVAL ............................. 51 DISASSEMBLY ......................... 53 ASSEMBLY ............................ 69 INSTALLATION ......................... 85 SCHEMATICS AND DIAGRAMS - 42RLE TRANSMISSION ...................... 88 SPECIFICATIONS 42RLE AUTOMATIC TRANSMISSION ...... 101 SPECIAL TOOLS 42RLE AUTOMATIC TRANSMISSION ...... 103 ACCUMULATOR DESCRIPTION ........................ 106 OPERATION .......................... 106 ADAPTER HOUSING SEAL REMOVAL ............................ 106 INSTALLATION ........................ 106 BEARINGS ADJUSTMENTS BEARING ADJUSTMENT PROCEDURES . . . 106 BRAKE TRANSMISSION SHIFT INTERLOCK MECHANISM DESCRIPTION ........................ 107 OPERATION .......................... 108 REMOVAL ............................ 108 INSTALLATION ........................ 108 ADJUSTMENTS ADJUSTMENT - BRAKE TRANSMISSION SHIFT INTERLOCK CABLE ............. 108 DRIVING CLUTCHES DESCRIPTION ........................ 109 OPERATION .......................... 109 FLUID AND FILTER DIAGNOSIS AND TESTING DIAGNOSIS AND TESTING - CAUSES OF BURNT FLUID ....................... 110 EFFECTS OF INCORRECT FLUID LEVEL . . 110 FLUID CONTAMINATION ............... 110 STANDARD PROCEDURE STANDARD PROCEDURE - FLUID LEVEL CHECK ............................. 111 STANDARD PROCEDURE - FLUID/FILTER SERVICE ........................... 111 STANDARD PROCEDURE - TRANSMISSION FILL ............................... 112 GEARSHIFT CABLE REMOVAL ............................ 113 INSTALLATION ........................ 113 HOLDING CLUTCHES DESCRIPTION ........................ 114 OPERATION .......................... 114 INPUT CLUTCH ASSEMBLY DISASSEMBLY ........................ 114 ASSEMBLY ........................... 121 INPUT SPEED SENSOR DESCRIPTION ........................ 131 OPERATION .......................... 131 REMOVAL ............................ 131 INSTALLATION ........................ 132 OIL PUMP DESCRIPTION ........................ 132 OPERATION .......................... 132 DISASSEMBLY ........................ 132 ASSEMBLY ........................... 133 OUTPUT SPEED SENSOR DESCRIPTION ........................ 134 OPERATION .......................... 134 REMOVAL ............................ 134 INSTALLATION ........................ 134 OVERDRIVE SWITCH DESCRIPTION ........................ 135 OPERATION .......................... 135 REMOVAL ............................ 135 INSTALLATION ........................ 135 PLANETARY GEARTRAIN DESCRIPTION ........................ 136 OPERATION .......................... 136 OIL PUMP SEAL REMOVAL ............................ 136 INSTALLATION ........................ 136 TJ AUTOMATIC TRANSMISSION - 42RLE 21 - 37

SHIFT MECHANISM DESCRIPTION ........................ 136 OPERATION .......................... 136 DIAGNOSIS AND TESTING - SHIFT MECHANISM ........................ 136 ADJUSTMENTS - SHIFT MECHANISM ...... 137 SOLENOID DESCRIPTION ........................ 137 OPERATION .......................... 138 SOLENOID/PRESSURE SWITCH ASSY DESCRIPTION ........................ 138 OPERATION .......................... 139 REMOVAL ............................ 139 INSTALLATION ........................ 140 TORQUE CONVERTER DESCRIPTION ........................ 141 OPERATION .......................... 145 REMOVAL ............................ 146 INSTALLATION ........................ 146 TRANSMISSION CONTROL RELAY DESCRIPTION ........................ 146 OPERATION .......................... 147 TRANSMISSION RANGE SENSOR DESCRIPTION ........................ 147 OPERATION .......................... 147 REMOVAL ............................ 148 INSTALLATION ........................ 148 TRANSMISSION TEMPERATURE SENSOR DESCRIPTION ........................ 149 OPERATION .......................... 149 VALVE BODY DESCRIPTION ........................ 149 OPERATION .......................... 150 REMOVAL ............................ 153 DISASSEMBLY ........................ 154 ASSEMBLY ........................... 159 INSTALLATION ........................ 164 AUTOMATIC TRANSMISSION - 42RLE DESCRIPTION The 42RLE (Fig. 1) is a four-speed transmission that is a conventional hydraulic/mechanical assembly controlled with adaptive electronic controls and mon- itors. The hydraulic system of the transmission con- sists of the transmission 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 transmission consist 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 Control of the transmission 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) portion of the Powertrain Control Module (PCM). The TCM is the heart of the electronic control system and relies on information from various direct and indirect inputs (sensors, switches, etc.) to determine 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 DRBt scan tool. 21 - 38 AUTOMATIC TRANSMISSION - 42RLE TJ

Fig. 1 42RLE Automatic Transmission TJ AUTOMATIC TRANSMISSION - 42RLE 21 - 39 AUTOMATIC TRANSMISSION - 42RLE (Continued)

TRANSMISSION IDENTIFICATION The 42RLE transmission can be identified by a barcode label that is affixed to the upper left area of the bellhousing. The label contains a series of digits that can be translated into useful information such as transmission part number (10), date of manufacture (4, 5), manufacturing origin (2), assembly line identifier (6), build sequence number (7), etc. (Fig. 2). If the tag is not legible or is missing, the “PK” number, which is stamped into the left rear flange of the transmission case, can be referred to for identification. The entire part number, build code, and sequence number are stamped into the flange. OPERATION The 42RLE transmission ratios are: First 2.84 : 1 Second 1.57 : 1 Third 1.00 : 1 Overdrive 0.69 : 1 Reverse 2.21 : 1 1 - DRIVEPLATE 6 - REVERSE CLUTCH 11 - STUB SHAFT 2 - TORQUE CONVERTER 7 - FRONT PLANET CARRIER 12 - LOW/REVERSE CLUTCH 3 - INPUT SHAFT 8 - REAR PLANET CARRIER 13 - 2/4 CLUTCH 4 - UNDERDRIVE CLUTCH 9 - OUTPUT SHAFT 14 - OIL PUMP 5 - OVERDRIVE CLUTCH 10 - SNAP RING Fig. 2 Identification Label Breakdown 1 - T=TRACEABILITY 2 - SUPPLIER CODE (PK=KOKOMO) 3 - COMPONENT CODE (TK=KOKOMO TRANSMISSION) 4 - BUILD DAY (350=DEC. 15) 5 - BUILD YEAR (1=2001) 6 - ASSEMBLY LINE CODE 7 - BUILD SEQUENCE NUMBER 8 - LAST THREE OF P/N 9 - CHANGE LEVEL 10 - TRANSMISSION PART NUMBER 11 - P=PART NUMBER 21 - 40 AUTOMATIC TRANSMISSION - 42RLE TJ AUTOMATIC TRANSMISSION - 42RLE (Continued)

FIRST GEAR POWERFLOW In first gear range, torque input is through the underdrive clutch (1) (Fig. 3) to the underdrive hub assembly. The underdrive hub is splined to the rear sun gear. When the underdrive clutch is applied, it rotates the underdrive hub and rear sun gear. The L/R clutch (2) is applied to hold the front carrier/rear annulus assembly. The rear sun gear drives the rear planetary pinion gears. The rear planetary pinion gears are forced to walk around the inside of the stationary rear annulus gear. The pinions are pinned to the rear carrier and cause the rear carrier assembly to rotate as they walk around the annulus gear. This provides the torque output for first gear. The other planetary gearset components are freewheeling. The first gear ratio is 2.84:1. Fig. 3 First Gear Powerflow 1 - UNDERDRIVE CLUTCH APPLIED (Turns Rear Sun) 2 - LOW-REVERSE CLUTCH APPLIED (Holds Rear Annulus/Front Carrier) TJ AUTOMATIC TRANSMISSION - 42RLE 21 - 41 AUTOMATIC TRANSMISSION - 42RLE (Continued)

SECOND GEAR POWERFLOW Second gear is achieved by having both planetary gear sets (Fig. 4) contribute to torque multiplication. As in first gear, torque input is through the underdrive clutch (1) to the rear sun gear. The 2/4 clutch (2) is applied to hold the front sun gear stationary. The rotating rear sun gear turns the rear planetary pinions. The rear pinions rotate the rear annulus/ front carrier assembly. The pinions of the front carrier walk around the stationary front sun gear. This transmits torque to the front annulus/rear carrier assembly, which provides output torque and a gear ratio of 1.57:1. Fig. 4 Second Gear Powerflow 1 - UNDERDRIVE CLUTCH APPLIED (Turns Rear Sun) 2 - 2-4 CLUTCH APPLIED (Holds Front Sun) 21 - 42 AUTOMATIC TRANSMISSION - 42RLE TJ AUTOMATIC TRANSMISSION - 42RLE (Continued)

THIRD GEAR POWERFLOW In third gear, two input clutches are applied to pro- vide torque input: the underdrive clutch (1) (Fig. 5) and overdrive clutch (2). The underdrive clutch rotates the rear sun gear, while the overdrive clutch rotates the front carrier/rear annulus assembly. The result is two components (rear sun gear and rear annulus gear) rotating at the same speed and in the same direction. This effectively locks the entire planetary gearset together and is rotated as one unit. The gear ratio in third is 1:1. Fig. 5 Third Gear Powerflow 1 - UNDERDRIVE CLUTCH APPLIED (Turns Rear Sun) 2 - OVERDRIVE CLUTCH APPLIED (Turns Front Carrier/Rear Annulus) TJ AUTOMATIC TRANSMISSION - 42RLE 21 - 43 AUTOMATIC TRANSMISSION - 42RLE (Continued)

FOURTH GEAR POWERFLOW In fourth gear input torque is through the overdrive clutch (1) (Fig. 6) which drives the front carrier. The 2/4 clutch (2) is applied to hold the front sun gear. As the overdrive clutch rotates the front carrier, it causes the pinions of the front carrier to walk around the stationary front sun gear. This causes the front carrier pinions to turn the front annulus/rear carrier assembly which provides output torque. In fourth gear, transmission output speed is more than engine input speed. This situation is called overdrive and the gear ratio is 0.69:1. Fig. 6 Fourth Gear Powerflow 1 - OVERDRIVE CLUTCH APPLIED (Turns Rear Sun) 2 - 2-4 CLUTCH APPLIED (Holds Front Sun) 21 - 44 AUTOMATIC TRANSMISSION - 42RLE TJ AUTOMATIC TRANSMISSION - 42RLE (Continued)

REVERSE GEAR POWERFLOW In reverse, input (Fig. 7) power is through the reverse clutch (1). When applied, the reverse clutch drives the front sun gear through the overdrive hub and shaft. The L/R clutch (2) is applied to hold the front carrier/rear annulus assembly stationary. The front carrier is being held by the L/R clutch so the pinions are forced to rotate the front annulus/rear carrier assembly in the reverse direction. Output torque is provided, in reverse, with a gear ratio of 2.21:1. Fig. 7 Reverse Gear Powerflow 1 - LOW-REVERSE CLUTCH APPLIED (Holds Rear Annulus Front Carrier) 2 - REVERSE CLUTCH APPLIED (Turns Front Sun) TJ AUTOMATIC TRANSMISSION - 42RLE 21 - 45 AUTOMATIC TRANSMISSION - 42RLE (Continued)

DIAGNOSIS AND TESTING DIAGNOSIS AND TESTING - AUTOMATIC TRANSMISSION CAUTION: Before attempting any repair on the 42RLE Four Speed Automatic Transmission, always check for proper shift cable adjustment. Also check for diagnostic trouble codes with the DRBT scan tool and the 42RLE Transmission Diagnostic Proce- dure Manual. 42RLE automatic transmission malfunctions may be caused by these general conditions: • Poor engine performance • Improper adjustments • Hydraulic malfunctions • Mechanical malfunctions • Electronic malfunctions When diagnosing a problem always begin with recording the complaint. The complaint should be defined as specific as possible. Include the following checks: • Temperature at occurrence (cold, hot, both) • Dynamic conditions (acceleration, deceleration, upshift, cornering) • Elements in use when condition occurs (what gear is transmission in during condition) • Road and weather conditions • Any other useful diagnostic information. After noting all conditions, check the easily acces- sible variables: • Fluid level and condition • Shift cable adjustment • Diagnostic trouble code inspection Then perform a road test to determine if the problem has been corrected or that more diagnosis is nec- essary. If the problem exists after the preliminary tests and corrections are completed, hydraulic pressure checks should be performed. DIAGNOSIS AND TESTING - ROAD TEST Prior to performing a road test, verify that the fluid level, fluid condition, and linkage adjustment have been approved. During the road test, the transmission should be operated in each position to check for slipping and any variation in shifting. If the vehicle operates properly at highway speeds, but has poor acceleration, the converter stator over- running clutch may be slipping. If acceleration is nor- mal, but high throttle opening is needed to maintain highway speeds, the converter stator clutch may have seized. Both of these stator defects require replacement of the torque converter and thorough transmission cleaning. Slipping clutches can be isolated by comparing the “Elements in Use” chart with clutch operation encountered on a road test. This chart identifies which clutches are applied at each position of the selector lever. A slipping clutch may also set a DTC and can be determined by operating the transmission in all selector positions. 21 - 46 AUTOMATIC TRANSMISSION - 42RLE TJ AUTOMATIC TRANSMISSION - 42RLE (Continued)

Jeep 42RLE Automatic Transmission Service & Repair Manual

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