Automatic Transaxle Overhaul & Testing - 4T60-E: Other Oldsmobile Eighty-Eight X

ON-VEHICLE SERVICE

The following components can be serviced without removing transaxle from vehicle.

1. Case Side Cover Pan
2. Converter-To-Flexplate Bolts
3. Cooler Lines
4. Drive Axles
5. Filler Pipe
6. Final Drive
7. Forward Servo
8. Reverse Servo
9. Scavenger Oil Scoop
10. Shift Control Cable
11. Solenoids
12. Speed Sensor
13. Thermal Element
14. Transaxle Pan
15. Transaxle Filter
16. Vacuum Modulator
17. Valve Body
18. Wiring Harness
19. 1-2 Servo
20. 1-2 Or 3-4 Accumulator Assemblies
21. 2nd, 3rd And 4th Gear Pressure Switches (if equipped)

VALVE BODY

See OIL PUMP & VALVE BODY under TRANSAXLE DISASSEMBLY.

DRIVE AXLE SHAFTS

See appropriate AXLE SHAFTS - FRONT article in DRIVE AXLES.

QUICK CHECK

1. Check level and condition of transaxle fluid. Check PCM memory for stored Diagnostic Trouble Codes (DTCs). See DTC checking procedures in «AUTO TRANS DIAGNOSIS - 4T60-E - 1995»(ref-56003) article or procedures in «AUTO TRANS DIAGNOSIS - 4T60-E - 1996»(ref-56004) article. If no DTCs are present, go to next step. If DTCs are present, diagnose and repair all PCM-related trouble codes. Clear PCM trouble code memory.
2. Perform road test. See «ROAD TEST»(ref-25523-S22684074592001011700000) under TESTING. During road test, record shift points. If shift point timing or shifting is incorrect, see diagnostic procedures in «AUTO TRANS DIAGNOSIS - 4T60-E - 1995»(ref-56003) article or go to «AUTO TRANS DIAGNOSIS - 4T60-E - 1996»(ref-56004) article.
3. If shift(s) is too harsh or too soft, see «HYDRAULIC PRESSURE TESTS»(ref-25523-S40853259062001011700000) under TESTING. For specific complaints, see appropriate condition(s) listed under «SYMPTOM DIAGNOSIS»(ref-25523-S06105088102001011700000) .

Oil Out Of Vent Or Foaming

Transaxle overfilled. Oil contaminated with antifreeze or engine overheating. Oil filter "O" ring damaged or missing. Thermo element in case does not close when hot, incorrect pin height or thermo element incorrectly installed. Modulator "O" ring incorrectly installed or damaged. Drive sprocket support drain back holes plugged.

High Or Low Line Pressure

Incorrect oil level. Vacuum line leaking, pinched, disconnected or cut. Aspirator "T" connection installed backward or blocked. Modulator diaphragm damaged. Modulator valve nicked, scored or stuck. Oil pump assembly seals or vanes damaged or slide stuck. Pump drive shaft damaged. Pressure regulator valve spring damaged or pressure regulator valve nicked or scored. Pressure relief valve spring damaged or ball missing. Check balls missing in control valve body. Pump or case cover leaking (bolts loose).

Delayed Engagement

Low fluid level. Oil cooler check ball not seating. Reverse servo or forward servo seals cut or damaged. Cut or damaged input housing piston seal. Damaged forward servo seals or servo assembly.

No Drive In "D"

1. Low oil level or line pressure. Manual linkage misadjusted or disconnected. Piston or seal damaged in forward servo assembly. Drive axles disengaged. Leaking or damaged 2-1 servo oil pipe seals. Damaged oil pump drive shaft or pump assembly. Incorrect No. 3 check ball location. Torque converter stator roller clutch damaged. Input clutch accumulator piston seal damaged. Drive link assembly damaged, drive link chain broken or sprockets and bearings damaged.
2. Input clutch assembly plates burned, clutch plates missing, check ball capsule leaking or missing. Input piston seals cut or damaged, or shaft feed passages blocked. Damaged or incorrectly assembled input sprag or input sun gear assembly. Burned 3rd roller clutch (due to lack of lubrication), oil lube pipe leaking or damaged.
3. Input carrier and reaction carrier assembly pinions, internal ring gear or sun gear damaged. Output shaft damaged or drive axles incorrectly assembled into differential. Burned 1-2 band assembly or band out of position. Parking pawl spring broken. Damaged final drive assembly or final drive sun gear, side gears, pinion gears or internal ring gear.

Slips In "D"

Low fluid level. Vacuum line pinched or cut. Damaged modulator. Low line pressure. Oil pump assembly seals or vanes damaged or slide stuck. Modulator valve stuck or binding. Damaged forward servo assembly or leaking servo piston seal. Oil filter screen plugged. Leaking or damaged servo pipe seals. Torque converter stator roller clutch not holding. Input clutch accumulator piston or input shaft seals damaged. Leaking ball capsule or damaged input clutch assembly seals. Check for problem with solenoid "A" or "B". Check for switched wires between TCC and solenoid "B".

No 1-2 Shift (1st Gear)

Check for binding or stuck 1-2 shift valve. Spacer plate or gaskets mispositioned or damaged. Drive sprocket support oil sealing rings damaged. Clutches in 2nd clutch assembly damaged. Piston or piston seals in 2nd clutch damaged. Incorrectly assembled 2nd clutch. Missing or damaged check ball capsule in 2nd clutch housing. Reverse reaction drum splines damaged or reverse reaction drum plate missing.

Harsh Or Soft 1-2 Shift

High or low line pressures. Damaged 1-2 accumulator piston seals or piston springs missing. Accumulator cover bolts improperly tightened or gaskets mispositioned. Accumulator valve in control valve body stuck. Incorrect No. 2 check ball location. Damaged seals on driven support sprocket.

1-2 Shift Shudder

Damaged 2nd clutch or driven sprocket support.

No 2-3 Shift (1st & 2nd Gears)

Check for DTCs. Diagnose and repair as necessary. Solenoid "B" stuck on. Dirt in solenoid, PCM signal to solenoid "B" grounded or signal return wire shorted to ground.

1-4 Shift (Misses 2nd & 3rd Gears)

Check for DTCs. Diagnose and repair as necessary. Solenoid "A" stuck on. Dirt in solenoid, PCM signal to solenoid "A" grounded or signal return wire shorted to ground.

2-3 Shift Only

Check for DTCs. Diagnose and repair as necessary. Failed solenoid "A" (solenoid off). Dirt in filter, PCM not grounded, leaking "O" ring, no supply voltage to solenoid "A" or wire disconnected.

1-2-4 Shift (No 2-3 Shift)

Stuck 2-3 shift valve or 3-2 manual shift valve. Mispositioned or damaged channel plate gasket. Blocked 3rd clutch port in driven sprocket support. Seals damaged or leaking in input shaft. Burned 3rd clutch assembly. Damaged or incorrectly assembled 3rd roller clutch assembly.

Harsh Or Soft 2-3 Shift

Low or high oil pressures. Mispositioned No. 4 check ball causing soft shift. Leaking 2-3 accumulator piston. Missing No. 9 check ball causing harsh shift.

Early Or Late 2-3 Shift

Wrong PROM. Check for possible service bulletins.

3-4 Shift (Misses 1st & 2nd Gears)

Check for DTCs. Diagnose and repair as necessary. Solenoid "B" stuck off. Dirt in solenoid, "O" ring leaking, PCM signal to solenoid "B" grounded or signal return wire shorted to ground.

No 3-4 Shift

Check for manual shift linkage out of adjustment. Sticking 3-4 shift valve. Splines on 4th clutch shaft damaged. Burned 4th clutch assembly plates, damaged piston seals or incorrect number of clutch plates.

Harsh Or Soft 3-4 Shift

High or low line pressures. Accumulator cover bolts improperly tightened. Damaged accumulator seals or pistons. Check for stuck 3-4 accumulator valve in control valve body or missing No. 10 check ball.

Early Or Late 3-4 Shift

Wrong PROM. Check for possible service bulletins.

No Reverse

1. Low oil pressure. Reverse servo or apply pin incorrectly assembled, piston or seal damaged. Damaged oil pump drive shaft or oil pump assembly. Input clutch accumulator piston seal damaged. Drive link assembly damaged or drive link chain broken. Burned, damaged or mispositioned reverse band. Input clutch assembly plates burned, clutch plates missing or check ball capsule leaking or missing.
2. Input piston seals cut or damaged, or shaft feed passages blocked. Damaged or incorrectly assembled input sprag or input sun gear assembly. Reverse reaction drum splines damaged. Burned 3rd roller clutch (due to lack of lubrication), or oil lube pipe leaking or damaged.
3. Input carrier and reaction carrier assembly pinions, internal ring gear or sun gear damaged. Output shaft damaged or drive axles incorrectly assembled into differential assembly. Damaged solenoid "A" or TCC solenoid. Parking pawl spring broken. Damaged final drive assembly or final drive sun gear, side gears, pinion gears or internal ring gear.

Locked In Reverse

Damaged parking pawl binding on final drive internal gear.

Slips In Reverse

Low oil pressure. Reverse servo seal damaged. Reverse reaction drum splines stripped.

Vehicle Moves In Park

Manual linkage damaged or disconnected. Broken final drive parking pawl spring, parking pawl or parking pawl gear in final drive internal gear assembly. Park actuator spring damaged.

Harsh Neutral-To-Drive Engagement

Engine idle too high. Loss of vacuum due to damaged lines, aspirator "T" or modulator. Aspirator "T" installed backward or plugged. Reverse servo cushion spring weak or broken. Check ball No. 5 missing (also harsh engagement in Reverse). Check ball No. 6 is missing. Control valve body spacer plate mispositioned. Thermal element does not close when warm. Reverse servo apply pin too long.

Vehicle Starts In 2nd Gear

Stuck 1-2 shift valve.

Harsh Reverse

Scored 2nd clutch housing. Burned reverse band fiber. Check for missing or mispositioned check ball No. 5, or damaged or wrong servo cushion spring.

No Engine Braking In Manual 2nd Or Low

Burned 1-2 band. Apply pin not engaging 1-2 band. Apply servo seals leaking, servo cover loose or piston binding in bore.

Harsh 4-3 Downshift

Missing No. 10 check ball in control valve body. 3-4 accumulator valve stuck or 3-4 accumulator seal cut.

Harsh 3-2 Downshift

No. 9 check ball in control valve body missing. 2-3 accumulator valve stuck or 2-3 accumulator seal cut.

Harsh 2-1 Downshift

Wrong spacer plate, stuck 1-2 accumulator valve or cut 1-2 accumulator seal.

Note. PCM controls TCC, PWM solenoid (if equipped) and shift solenoids "A" and "B".

No Converter Clutch Apply

Verify proper PCM operation and vehicle wiring. Coolant temperature sensor damaged. Damaged wiring harness or pinched wires. Solenoid inoperative. Converter clutch shift valve in control valve body stuck. Converter clutch apply valve stuck. Solenoid "O" ring leaking or screen blocked.

Torque converter external leaks at hub weld area, or fluid unbalanced or contaminated. Turbine shaft seals damaged. Oil pump drive shaft seal damaged. Channel plate converter clutch blow-off check ball not seated or damaged. Damaged or missing TCC accumulator piston or seal (without PWM solenoid only).

Converter Clutch Does Not Release

PCM-controlled TCC solenoid does not exhaust. Control valve body converter clutch apply valve stuck in apply position. TCC orifice screen missing.

Converter Clutch Stuck On In 3rd & 4th

TCC solenoid stuck on. Dirt in TCC solenoid. Wire between TCC solenoid and PCM shorted to ground.

Converter Applied With Maximum Pressure (With PWM)

PWM solenoid always off. Dirt in solenoid. Leaky "O" ring. No voltage to PWM solenoid. Open wire or no apply signal from PCM.

Converter Clutch Apply Rough, Slips Or Shudders

Control valve body converter clutch regulator valve stuck. Turbine shaft seals damaged or missing. Converter clutch blow-off check ball not sealed or damaged. Damaged channel plate converter clutch accumulator piston or seal (if equipped). Spring damaged. Wrong blow-off spring. Seals damaged or missing. Defective converter clutch.

No TCC

Check for DTCs. Diagnose and repair as necessary. Check the following solenoids and switches for faulty operation, dirt or binding: TCC solenoid, PWM, brake switch, PRNDL ("P"/"N" switch) and coolant temperature sensor. Check same solenoid and switch circuits for open or shorted wires between voltage supply or PCM.

Scheme 48

Gear Selector Position "D" (Overdrive)

1. With gear selector in "D" (overdrive) position, steadily increase throttle pressure to accelerate vehicle. Note shift speed engagement points in 2nd gear, 3rd gear and overdrive gear. Use chart as a reference for proper shift speeds. (Scheme 49) Also note Torque Converter Clutch (TCC) engagement point while in 3rd gear or Overdrive. NOTE: Ensure TCC engages in 3rd gear or overdrive during the following steps. On vehicles with PWM solenoid, TCC engagement point may be hard to feel. Use scan tool to indicate TCC engagement and release points.
2. At vehicle speeds of 40-50 MPH, quickly depress accelerator to half-open position (part throttle detent downshift). TCC should release, and transaxle should immediately downshift to 3rd gear.
3. At vehicle speeds of 40-50 MPH, quickly depress accelerator to wide open position (full throttle detent downshift). TCC should release, and transaxle should immediately downshift to 2nd gear.
4. At vehicle speeds of 40-55 MPH, release accelerator pedal while moving gear selector to "3" (third gear) position. TCC should release, transaxle should downshift into 3rd gear, and engine braking should slow vehicle.
5. Move gear selector to "D" (overdrive) position, and accelerate to 40-45 MPH. Release accelerator pedal while moving gear selector to "2" (2nd gear) position. TCC should release, transaxle should downshift to 2nd gear immediately, and engine braking should slow vehicle.
6. Move gear selector to "D" (overdrive) position, and accelerate to 25 MPH. Release accelerator pedal while moving gear selector to "1" (1st gear) position. TCC should release, transaxle should downshift to 1st gear and engine braking should slow vehicle.
7. With gear selector in "D" (overdrive) position, accelerate vehicle to overdrive gear with TCC applied. Release accelerator pedal, and lightly apply brakes. TCC should release. Note speeds at which vehicle downshifts. (Scheme 49)

Gear Selector Position "3" (3rd Gear)

With vehicle stopped, move gear selector to "3" (3rd gear) position and steadily increase throttle pressure to accelerate vehicle. Note speeds at which vehicle shifts into 2nd and 3rd gears. (Scheme 49) Also note when TCC engages while in 3rd gear.

Gear Selector Position "2" (2nd Gear)

With vehicle stopped, move gear selector to "2" (2nd gear) position. Accelerate vehicle and note speed at which vehicle shifts from 1st gear to 2nd gear. Accelerate vehicle to 25 MPH. Transaxle should not shift into 3rd gear, and TCC should not engage.

Gear Selector Position "1" (1st Gear)

With vehicle stopped, move gear selector to "1" (1st gear) position. Accelerate vehicle to 15 MPH. Transaxle should not upshift, and TCC should not engage.

Scheme 49

HYDRAULIC PRESSURE TESTS

1. Before performing hydraulic pressure tests, check fluid level and condition. Check manual control linkages for correct adjustment, and ensure engine is properly tuned.
2. Connect tachometer to engine, hand-held vacuum pump to vacuum modulator and oil pressure gauge to line pressure test port. see scheme 1 Check line pressure at specified engine RPM. (Scheme 50)

Note. Hydraulic pressure is controlled by pump output and regulated by pressure regulator valve. Line pressure is boosted by reverse boost valve when gear selector is in "R" and "D1" positions. Line pressure should increase with throttle opening due to decrease in engine vacuum to modulator.

Minimum Line Pressure Check

Start engine, and apply 18 in. Hg to vacuum modulator. Record line pressure readings in all gear selector positions with engine running at specified RPM, and compare recorded pressures to specifications. (Scheme 50) If recorded pressure is incorrect, see HIGH OR LOW LINE PRESSURE under TROUBLE SHOOTING.

Full Line Pressure Check

Release vacuum applied to modulator. Record line pressure readings in all gear selector positions with engine running at specified engine RPM. Compare recorded pressures to specifications. (Scheme 50) If pressure recorded is incorrect, see HIGH OR LOW LINE PRESSURE under TROUBLE SHOOTING.

Scheme 50

End Play Check

Mount Torque Converter End Play Fixture (J-35138) and Dial Gauge (J-8001) on torque converter to check end play. End play should be 0-.020" (0-0.50 mm). (Scheme 51)

Scheme 51

REAR SECTION

Thoroughly clean transaxle exterior. Drain fluid, and remove torque converter. Place transaxle in holding fixture. Remove speed sensor and rear extension housing.

LOWER SECTION

Remove bottom oil pan, oil filter, accumulator cover with 2-1 servo feed and return pipes. Remove modulator and modulator valve. Check modulator with known good modulator and Tester (36619). If necessary, replace modulator. Remove all retainers, gaskets, pipes, 2-1 manual servo assembly and accumulator piston assemblies from bores ( DO NOT interchange springs). (Scheme 52)

Scheme 52

OIL PUMP & VALVE BODY

1. Remove side cover attaching bolts, nuts and washers. Remove side cover and gaskets. Disconnect wiring harness from pressure switches, solenoid and case connector. Remove wiring harness.
2. Remove linkage and bracket from valve body assembly. Remove oil pump assembly bolts to remove oil pump from valve body. (Scheme 53) Remove servo pipe retainer bolt and retainer plate. Remove remaining mounting bolts from valve body, and remove valve body from channel plate.
3. Remove spacer plate and gaskets. Remove oil pump drive shaft. Remove 6 check balls between channel plate and spacer plate. Remove 4 check balls between spacer plate and valve body.

Scheme 53

Drive Sprocket Support

1. If removal of drive sprocket bearing from case is necessary, use Bearing Puller (J-26941) and Slide Hammer (J6125-1B). (Scheme 54) Remove support bearing, and install NEW bearing with Bearing Installer (J-28677) and Driver Handle(J-8092).
2. If drive sprocket support replacement is necessary, remove attaching screws and remove support. Install NEW support, and tighten attaching screws to specification. See «TORQUE SPECIFICATIONS»(ref-25523-S13420361302001011700000).

Note. DO NOT remove these parts unless replacement is necessary.

Manual Shaft, Detent Lever & Actuator Rod

If manual shaft, detent lever or actuator rod removal is necessary, remove pin and lock nut from manual shaft. Remove actuator rod from detent lever. Remove retaining pin from case. Remove actuator rod assembly from case. Remove "O" ring from actuator rod guide.

Scheme 54

Input Clutch Plate Update

1. Beginning August 22, 1994, (Julian Date 234), all 1995 4T60-E transaxles were produced with composition and steel input clutch plates using a revised thickness. Original design steel plates are no longer available from manufacturer. Revision greatly improves durability of input clutch plates.
2. Revised composition plate is thinner by about .026" (.0010 mm) to accommodate thicker steel plate. Composition plate is about .065" (.0025 mm) thick. Original design composition plate is about .091" (.0036 mm) thick.
3. Revised steel plate is thicker by about .020" (.0007 mm) to improve heat displacement and durability. Plate is about .070" (.0028 mm) thick. Original design plate is about .050" (.0020 mm) thick. Revised steel plate is same as used on 3T40 transaxle.
4. Revised Input Clutch Pack (24203185) will service all 1991-95 4T60-E transaxles. Clutch pack also will service 4T60 transaxles from late 1990 (Julian Date 016 and later) through 1993. These transaxles have had the input clutch accumulator eliminated and a wave plate added to input clutch housing.
5. Clutch pack CANNOT be used on 4T60 transaxles prior to Julian Date 016. Original design and revised clutch plates CANNOT be mixed. For input clutch plate part numbers, see «INPUT CLUTCH PLATE PART NUMBERS»(ref-25523-S06440194942001011700000) .

INPUT CLUTCH PLATE PART NUMBERS

Scheme 55

Scheme 56

Drive Link Chain Design Update

1. 1995-96 vehicles equipped with 4T60-E transaxle are equipped with 2 NEW design rocker joint drive link chains. First design ("Elastically Tuned") fits all models except Aurora and Riviera. This drive link chain has strength improvements to improve high-mileage durability.
2. Drive link chain can be identified by the "Mouse Ears" shape of outer guide links and has one Copper colored master link. see scheme 33 Drive link chain may replace original design rocker joint drive link chain on all 1993-95 vehicles. On all 1991-93 vehicles equipped with 4T60-E transaxle with round pin design drive link chain, drive link chain, drive sprocket and driven sprocket MUST be updated to NEW design. See «DRIVE LINK CHAIN & SPROCKET PART NUMBERS»(ref-25523-S03812755802001011700000).
3. Aurora and Riviera are equipped with second design rocker joint drive link chain specifically designed to reduce noise. see scheme 33 Chain is chordal compensating. Drive link chain can be identified by the 2 Copper colored master links. Internal links have a slightly different profile. For drive link chain part numbers, see «DRIVE LINK CHAIN & SPROCKET PART NUMBERS»(ref-25523-S03812755802001011700000).

DRIVE LINK CHAIN & SPROCKET PART NUMBERS