Overhaul - 4t60-e Buick Century V

APPLICATION

TRANSAXLE APPLICATIONS

BODY CODE DESIGNATIONS (1993 PASSENGER CARS)

BODY CODE DESIGNATIONS (1994 PASSENGER CARS)

SERIES CODE DESIGNATIONS (1993-94 VANS)

IDENTIFICATION

All transaxles have a metal identification plate attached to the rear face of transaxle case. (Scheme 57)

Scheme 57

DESCRIPTION

The Hydra-Matic 4T60-E transaxle is a fully automatic 4-speed unit consisting primarily of a 3-element hydraulic torque converter and converter clutch. Transaxle uses a variable capacity vane-type pump to supply all hydraulic pressure needed for operation.

The multiplied torque from torque converter is transferred to the transaxle by a sprocket and link chain assembly. Other internal components consist of 4 multiple-disc clutches, a roller clutch, a sprag clutch, 3 bands and a compound planetary gear set. The final drive gear and differential assemblies are an integral part of the transaxle.

The 4T60-E uses 2 electronic shift valves, controlled by the Powertrain Control Module (PCM), to switch hydraulic pressure on or off. Another electronic solenoid controls Torque Converter Clutch (TCC) lock-up. Some models also use a Pulse Width Modulated (PWM) solenoid to control rate of TCC apply.

LUBRICATION & ADJUSTMENTS

See appropriate TRANSMISSION SERVICING article.

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. Solenoid
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. 3rd & 4th Gear Pressure Switches (if equipped)

VALVE BODY

See OIL PUMP & VALVE BODY under TRANSAXLE DISASSEMBLY.

DRIVE AXLE SHAFTS

See appropriate AXLE SHAFTS article.

OIL COOLER FLUSHING

1. If available, fill Line Flusher (J-35944 ) with solution, and install oil cooler and line flusher to top transaxle cooler line on transaxle. Follow manufacturer's instructions to flush oil cooler and cooler lines.
2. If line flusher is not available, flush cooler and cooler lines with a mixture of clean solvent and water. Flush cooler in both directions until all old fluid and debris are removed. If necessary, replace plugged or damaged cooler and/or lines.

TROUBLE SHOOTING

Note. For testing and diagnostic procedures of electronic components, see GENERAL MOTORS HYDRA-MATIC 4T60-E DIAGNOSIS article.

Note. For clutch and band applications, refer to CLUTCH & BAND APPLICATION CHART in TROUBLE SHOOTING.

QUICK CHECK

1. Check level and condition of transaxle fluid. Check PCM memory for stored trouble codes. See «GENERAL MOTORS HYDRA-MATIC 4T60-E DIAGNOSIS»(ref-55737) article in the AUTO TRANS DIAGNOSIS section. If no trouble codes are present, go to next step. If codes are present, diagnose and repair all PCM-related trouble codes. Clear PCM trouble code memory.
2. Perform road test. See «ROAD TEST»(/buick/century/v-1982-1996/remont/automatic-trans/#overhaul-4t60-e__road-test) under TESTING. During road test, record shift points. If shift point timing or shifting is incorrect, see «GENERAL MOTORS HYDRA-MATIC 4T60-E DIAGNOSIS»(ref-55738) article for 1993 vehicles, or «GENERAL MOTORS HYDRA-MATIC 4T60-E DIAGNOSIS»(/buick/century/v-1982-1996/remont/automatic-trans/#diagnosis-4t60-e) article for 1994 vehicles.
3. If shift(s) is too harsh or too soft, see procedures for «HYDRAULIC PRESSURE TESTS»(/buick/century/v-1982-1996/remont/automatic-trans/#overhaul-4t60-e__hydraulic-pressure-tests) under TESTING.
4. For specific complaints, see appropriate condition(s) listed under «SYMPTOM DIAGNOSIS»(/buick/century/v-1982-1996/remont/automatic-trans/#overhaul-4t60-e__symptom-diagnosis) .

SYMPTOM DIAGNOSIS

Note. Transaxle uses a PCM computer, which controls TCC, PWM solenoid (if equipped) and shifting solenoids "A" and "B".

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 1-2 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 pressure. Manual linkage misadjusted or disconnected. Piston or seal damaged in 1-2 servo assembly. Drive axles disengaged. Leaking or damaged 1-2 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 clutch 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"

1. Low fluid level. Vacuum line pinched or cut. Damaged vacuum modulator. Low line pressure. Oil pump assembly seals or vanes damaged or slide stuck. Modulator valve stuck or binding. Damaged 1-2 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.
2. Check for problem with solenoid "A" or "B". Check for switched wires between TCC and solenoid "B".

Scheme 58

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 pack. 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)

Depending on vehicle, check for trouble Code 26, 29, 36, 56, 755 or 1650. 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)

Depending on vehicle, check for trouble Code 26, 29, 56 or 1650. Solenoid "A" stuck on. Dirt in solenoid, PCM signal to solenoid "A" grounded or signal return wire shorted to ground.

2-3 Shift Only

Depending on vehicle, check for trouble code 26, 29, 56 or 1650. Failed "A" solenoid ("A" solenoid off). Dirt in filter, PCM not grounded, leaking "O" ring, no supply voltage to "A" solenoid 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.

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

Depending on vehicle, check for trouble Code 26, 29, 36, 56, 755 or 1650. 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 clutch 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 assembly or missing No. 10 check ball.

Early Or Late 3-4 Shift

Wrong PROM.

No Reverse

1. Oil pressure low. Reverse servo incorrectly assembled, piston or seal damaged or apply pin incorrect. 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 clutch 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. Blown out "A" or TCC solenoid.
4. 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 park pawl spring, park pawl or park 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 vacuum 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 Breaking In Manual 2nd or Low

Burned 2-1 manual band. Apply pin not engaging 2-1 manual 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. Transaxle uses a PCM computer. This computer controls TCC, PWM solenoid (if equipped) and shifting 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 of control valve assembly 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 only).

Converter Clutch Does Not Release

PCM-controlled TCC solenoid does not exhaust. Control valve assembly 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 assembly 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

Depending on vehicle, check for possible trouble Code 15, 26, 27, 31, 38, 56, 90, 90, 117, 740 or 1640. 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. Also check the same solenoid and switch circuits for open or shorted wires between voltage supply or PCM.

CLUTCH & BAND APPLICATION CHART

CLUTCH & BAND APPLICATION CHART (4T60-E)

TESTING - ELECTRONIC SELF-DIAGNOSTICS

Note. For testing/diagnostic procedures of electronic components, see: GENERAL MOTORS HYDRA-MATIC 4T60-E DIAGNOSIS - 1993 GENERAL MOTORS HYDRA-MATIC 4T60-E DIAGNOSIS - 1994

ROAD TEST

Note. Before road testing vehicle, engine and transmission must be at operating temperature. Torque converter clutch will not engage if engine coolant has not reached operating temperature.

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 59)to (Scheme 62). 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 the "3" (third gear) position. The TCC should release, transaxle should downshift into 3rd gear, and engine braking should slow vehicle.
5. Move gear selector to the "D" (overdrive) position, and accelerate to 40-45 MPH. Release accelerator pedal while moving gear selector to the "2" (2nd gear) position. The TCC should release, transaxle should downshift to 2nd gear immediately, and engine braking should slow vehicle.
6. Move gear selector to the "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 the "D" (overdrive) position, accelerate vehicle to overdrive gear with TCC applied. Release accelerator pedal, and lightly apply brakes. The TCC should release. Note speeds at which vehicle downshifts. (Scheme 59)to (Scheme 62).

Scheme 59

Scheme 60

Scheme 61

Scheme 62

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 59)to (Scheme 62). Also note when TCC engages while in 3rd gear.

Gear Selector Position "2" (2nd Gear)

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

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 pressure gauge to line pressure test port. (Scheme 57) Check line pressure at specified engine RPM. (Scheme 63)or (Scheme 64).

Note. Hydraulic pressure is controlled by pump output and regulated by pressure regulator valve. Line pressure is boosted by reverse boost valve when selector is in "R" and "D1" positions. Line pressure should increase with throttle opening due to decrease in engine vacuum to vacuum 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 63)or (Scheme 64). If recorded pressure is incorrect, see HIGH OR LOW LINE PRESSURE heading under TROUBLE SHOOTING.

Full Line Pressure

Release vacuum applied to vacuum modulator. Record line pressure readings in all gear selector positions with engine running at specified engine RPM. Compare recorded pressures to specifications. (Scheme 63)or (Scheme 64). If pressure recorded is incorrect, see HIGH OR LOW LINE PRESSURE heading under TROUBLE SHOOTING.

Scheme 63

Scheme 64

REMOVAL & INSTALLATION

See appropriate REMOVAL & INSTALLATION article.

TORQUE CONVERTER INSPECTION

Torque converter must be replaced for any of the following reasons.

1. Damage to Pump Assembly
2. Metal Particles Present in Oil
3. Leaks in Hub Weld Area
4. Crankshaft Pilot Broken or Damaged
5. Hub Scored or Damaged
6. Stator Failure
7. Torque Converter Imbalance
8. Engine Coolant Contamination
9. Excessive End Play

TORQUE CONVERTER END PLAY CHECK

Mount Torque Converter End Play Fixture (J-35138) and Dial Gauge (J-8001) on stand to check end play. End play should be 0-.020" (0-0.50 mm). (Scheme 65)

Scheme 65

REAR TRANSAXLE ASSEMBLY

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

LOWER TRANSAXLE ASSEMBLY

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 and accumulator piston assemblies from bores ( DO NOT interchange springs). (Scheme 66)

Scheme 66

SERVO ASSEMBLIES

1. Apply inward pressure to top of reverse servo cover, and remove cover retaining ring. Remove reverse servo cover and reverse servo assembly from case. (Scheme 67)
2. Apply inward pressure to top of 1-2 servo cover, and remove servo cover retaining ring. Remove 1-2 servo cover and 1-2 servo assembly from case.

Scheme 67

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 pump assembly cover bolts to remove pump cover from valve body. (Scheme 68) Remove servo pipe retainer bolt and retainer plate. Remove remaining mounting bolts from valve body, and remove valve body from channel plate.
3. Remove oil dam from cavity above 4th clutch assembly. Remove 4 check balls between spacer plate and valve body. Remove 8 check balls between channel plate and spacer plate.

Scheme 68

CHANNEL PLATE ASSEMBLY & 4TH CLUTCH

1. Disconnect manual valve link from manual valve, and pull spring back. Place detent lever in Park position for clip removal. Remove channel plate attaching bolts. Remove channel plate and channel plate gaskets.
2. Remove oil pump drive shaft. Remove input clutch accumulator piston assembly and converter clutch accumulator piston assembly. Remove 4th clutch plates and apply plate. Remove 4th clutch hub thrust bearing. Remove 4th clutch hub and shaft. (Scheme 95)

FINAL DRIVE ASSEMBLY

1. Rotate output shaft until "C" ring opening is visible from beneath lower tapered end of transaxle case. Using "C" Ring Remover/Installer (J-34757 ), push "C" ring partially off shaft, then rotate shaft and remove ring with needle-nose pliers. Ring can also be removed with 2 long thin screwdrivers.
2. Check final drive end play. See «FINAL DRIVE ASSEMBLY»(/buick/century/v-1982-1996/remont/automatic-trans/#overhaul-4t60-e) under COMPONENT DISASSEMBLY & REASSEMBLY. (Scheme 73) Remove final drive assembly and selective thrust washer and bearing. Remove internal gear snap ring and internal gear from case.

DRIVE LINK ASSEMBLY

Note. (Scheme 92)for exploded view of all internal components (from drive link support to final drive assembly). (Scheme 93)for thrust washer and bearing locations. (Scheme 94)for lip seal locations.

1. Remove "O" ring from turbine shaft. (Scheme 95) Remove turbine shaft drive sprocket, driven sprocket and drive link chain together as an assembly. Note position of Copper-colored link on drive link chain; it should be installed facing up.
2. Remove drive sprocket and driven sprocket thrust washers from between sprockets and channel plate. Remove chain scavenging scoop and driven sprocket support with 2nd clutch thrust washer.

Note. If deflection of drive link chain exceeds 1 1/16", check drive link chain, sprockets and supports for wear; replace if necessary.

INPUT & 2ND CLUTCH ASSEMBLIES

1. Using Final Drive/Clutch Assembly Remover/Installer (J-33381 ), remove 2nd clutch and input shaft clutch housings as an assembly. (Scheme 70) Remove reverse band if it did not come out with 2nd clutch housing.
2. Remove thrust washers. Install input housing and shaft assembly back in transaxle. Install Loading Tool (J-26958 ) to transaxle case. (Scheme 69)
3. Measure input shaft clutch housing end play using End Play Gauge (J-33386 ). Record measurements for proper end play clearances during reassembly. (Scheme 69)
4. Fit proper selective thrust washer and measure clearance. Record measurement, and set aside proper selective washer for reassembly. Remove 2nd clutch and reverse band assembly as described previously in step 1.

Scheme 69

Scheme 70

INPUT SPRAG, SUN GEARS & 3RD ROLLER CLUTCH ASSEMBLIES

Remove input clutch sprag assembly, 3rd roller clutch assembly and input sun gear. Remove reverse band. Remove reverse reaction drum input carrier assembly and thrust bearing. Remove reaction carrier, reaction sun gear/drum assembly and 1-2 band. Remove reaction sun gear thrust bearing and final drive output shaft. Remove forward band. DO NOT clean assemblies in solvent.

Cleaning & Inspection

Clean transaxle case thoroughly with solvent, and then air dry. Inspect transaxle case for damage to band lugs, snap ring grooves and drive sprocket bearings. Check for interconnected or damaged oil passages and servo bores. Inspect case for stripped threads in bolt holes or casting porosity. Repair or replace case if necessary.

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 71) 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 specifications. See «TORQUE SPECIFICATIONS»(/buick/century/v-1982-1996/remont/automatic-trans/#overhaul-4t60-e) table at end of article.

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 71

Disassembly & Inspection

1. Inspect final drive internal gear for damaged teeth, worn bearing surfaces, broken parking pawl spring or damage to parking pawl. Inspect sun gear, thrust bearings, parking gear and governor drive gear for wear or damage.
2. Check final drive carrier pinion gears for excessive end play. Use a feeler gauge and measure end play between carrier and pinion gear thrust washer. End play should be.009-.025" (.24-.63 mm).
3. Using a pin punch, drive differential pinion shaft retainer pin from carrier. Remove pinion shaft, pinion and side gears, and thrust washers. (Scheme 72) Inspect all parts for damage or abnormal wear. Inspect final drive sun gear shaft for damaged splines or journals.

Reassembly

1. Assemble differential side gears and thrust washers into carrier. Using petroleum jelly, stick thrust washers onto pinion gears. Assemble pinion gears and washers into carrier.
2. Slide pinion shaft through both pinion gears for alignment, then remove shaft. Rotate pinion gears into position, then install pinion shaft. Tap retaining pin into position using a plastic hammer.
3. Tap speed sensor drive gear (if removed) into position using soft mallet. Install sun gear with stepped side facing out. Assemble parking gear on sun gear.
4. Inspect carrier-to-case selective thrust washer for damage. Install thrust washer onto carrier hub. Install thrust bearing onto thrust washer and retain with petroleum jelly.
5. Assemble thrust bearing on internal gear. Install internal gear to case and install snap ring. Move detent lever out of "P" position. Install final drive assembly into case.
6. To measure final drive end play, install dial indicator so pointer contacts Adapter (J-26958-10 ). (Scheme 73) Lift speed sensor drive gear with Snap Ring Remover (J-28585 ), and read dial indicator.
7. Correct end play is.005-.025" (.20-.62 mm). If necessary, adjust end play with selective carrier-to-case thrust washer. See «CARRIER-TO-CASE SELECTIVE THRUST WASHER SIZES»(/buick/century/v-1982-1996/remont/automatic-trans/#overhaul-4t60-e).

CARRIER-TO-CASE SELECTIVE THRUST WASHER SIZES

Scheme 72

Scheme 73

Inspection & Reassembly

Inspect final drive sun gear shaft for damaged splines or journals. (Scheme 92) Install thrust bearing. Install final drive sun gear shaft into final drive, ensuring splines engage with parking gear and sun gear.

Note. The 1-2 band assembly is presoaked in a friction solution. DO NOT wash band in solvent.

Inspection

DO NOT wash 1-2 band in solvent. Inspect 1-2 and forward band assembly for heat damage, lining cracks and separation. Check band stop for damage and replace if necessary.

Inspect reaction carrier and reaction drum for damaged teeth, scoring or warpage. Check thrust bearing for damage. Using a feeler gauge, check reaction carrier pinion gear end play. End play should be .009-.030" (.23-.77 mm). Check for damage to reaction carrier internal gear.

1. Install reaction sun gear-to-final drive internal gear thrust bearing, positioning inner race against internal gear. Assemble reaction sun gear and drum assembly onto final drive internal gear.
2. Install reaction carrier-to-sun gear thrust bearing, positioning inner race against reaction carrier. Retain bearing with petroleum jelly. Install reaction carrier, rotating carrier until pinions engage sun gear.

Check input carrier pinion gears for proper end play. Pinion gear end play should be .009-.030" (.23-.77 mm). Inspect internal gear and pinion gears for worn or damaged teeth, and ensure pinions rotate freely. Inspect thrust bearing for damage (thrust bearing cannot be removed from carrier).

Install thrust bearing with inside race against carrier. Retain thrust bearing with petroleum jelly. Install input carrier into case, and rotate into position.

Inspect reverse reaction drum for damaged teeth and distortion. Install reverse reaction drum, making sure spline teeth engage input carrier. DO NOT wash reverse band in solvent. Inspect reverse band assembly for damage and replace if necessary.

Disassembly

1. Disassemble 3rd roller clutch and input sprag from input sun gear. Remove input sun gear spacer and retainer from sun gear. Remove 3rd roller clutch outer race and cam from roller assembly. (Scheme 74)
2. Remove inner race from input sprag assembly. Remove one input sprag snap ring. Disassemble input sprag and wear plate.

Scheme 74

1. Inspect 3rd roller clutch outer race for scoring and wear. Inspect roller cam for cracks and damage. Inspect roller assembly for damaged rollers and springs. Install any loose roller by depressing spring and inserting roller.
2. Inspect input sprag inner and outer races for damage. Check sprag assembly for damaged sprags or cages. Check wear plates for scoring. Inspect input sun gear splines and bushing for damage.

1. Install roller cam into roller cage assembly, rotating cage so rollers are at lowest ramp position. Install roller clutch outer race over cage and cam.
2. Assemble one wear plate against snap ring. Install sprag assembly against wear plate with cross bar notches positioned correctly. (Scheme 75) Install other wear plate. Install snap ring.
3. Assemble spacer onto input sun gear. Assemble input sprag retainer, sprag assembly and roller clutch onto sun gear. Ensure input sprag and 3rd roller clutch hold while holding input sun gear. (Scheme 76)

Scheme 75

Scheme 76

1. Remove input shaft thrust washer and input clutch backing plate snap ring. Remove input clutch backing plate. Remove input clutch steel and composition plates. Remove input clutch apply plate.
2. Remove 3rd clutch backing plate snap ring and backing plate. Remove 3rd clutch steel and composition plates. (Scheme 77) Remove 3rd clutch sprag retainer snap ring. Using Clutch Spring Compressor (J-23327) and Adapter (J-25018-A), compress and remove spring retainer.
3. Remove 3rd clutch piston from housing. Remove 3rd clutch piston inner seal from shaft. Compress piston housing, and remove snap ring. Remove "O" ring. Remove spring and retainer assembly. Remove input clutch piston and inner seal.

Inspect all clutch plates for cracks, wear, lining separation, pits or other signs of damage. Inspect thrust washer for damage. Inspect input clutch housing and shaft for interconnected oil passages, damaged clutch hub, worn bushings, or damaged 3rd clutch shaft seal or oil seal rings.

Input Shaft Seal Replacement

1. Remove solid oil seal rings from input shaft. Inspect seal ring grooves for nicks or burrs. Lubricate each oil seal ring, and position them one at a time on Seal Protector (J-34741-1 ). (Scheme 78)
2. Quickly slide each seal into ring groove when protector is in position. Use Seal Driver (J-34741-2 ) to push ring over seal protector. Size seal with Seal Sizer (J-34741-3 ). Gently twist seal sizer over each seal. Leave sizer in place until installation.

Retainer & Ball Assembly Replacement

Remove retainer and ball assembly from housing using a 3/8" drift. Install new retainer and ball assembly.

Piston Seal Replacement

Remove seals from input clutch piston or 3rd clutch piston. Lubricate new seals with ATF, and install seals.

1. Lubricate input clutch piston inner seal with ATF, and install seal using Seal Protector (J-37361 ). Assemble input piston into input housing. Assemble "O" ring seal onto input shaft.
2. Install spring retainer and guide in piston. (Scheme 77) Install 3rd clutch piston housing into input housing. Using spring compressor, compress 3rd clutch housing, and install snap ring.
3. Install 3rd clutch inner seal. Install 3rd clutch piston into housing. Compress 3rd clutch spring retainer, and install snap ring.
4. Install wave plate. Assemble 3rd clutch plates; start with steel plate, and then alternate between composition and steel plates. Install 3rd clutch backing plate with stepped side facing up. Install snap ring.
5. Assemble input clutch plates; start with composition plate, and then alternate between steel and composition plates. Install input clutch backing plate with identification mark facing up.
6. Install snap ring. Apply air pressure to oil passages in input shaft, and check for proper operation of clutch. Air pressure must not exceed 90 psi (6.2 kg/cm 2 ).

Scheme 77

Scheme 78

Remove snap ring and backing plate. (Scheme 79) Remove clutch plates, waved plate and snap ring. Remove apply ring and spring return assembly. Remove apply piston.

1. Inspect steel and composition plates for wear, lining separation, pitting or damage. Inspect apply ring and spring return for damage. Inspect piston and piston seals for damage.
2. Inspect 2nd clutch housing for damaged inner piston seal. Inspect for damaged bushings and spline teeth. Check for scored band surface. Check retainer and ball assembly for damage. Inspect housing for warpage.

Scheme 79

Remove seal from 2nd clutch piston. Lubricate new seal with ATF and install.

Remove retainer and ball assembly from housing using a 3/8" drift. Tap in new retainer using drift.

Assemble piston into housing. Install apply ring and spring return. (Scheme 80) Install snap ring and wave plate. Assemble clutch plates; start with steel plate, and then alternate between composition and steel plates. Install backing plate and snap ring. Apply 90-psi (6.2 kg/cm 2 ) air pressure to passage marked "2" to check clutch operation.

Scheme 80

Compress spring return using a press, and remove snap ring. Remove retainer and 4th clutch piston from sprocket support.

1. Inspect driven sprocket support for worn or damaged oil seal rings. Check bushing and piston seal surface for damage. Check for blocked or interconnected oil passages and cup plug.
2. Check chain scavenging scoop and baffle for cracks. Inspect piston, seals and thrust washer for damage. Check spring retainer for distorted springs. Inspect driven sprocket bearing for damage.

Inspect output snap ring groove, splines, journal and bearings for damage. Replace if necessary.

Inspect drive and driven sprockets for damaged or chipped teeth. Check drive link chain for deflection greater than 1 1/16". Replace drive link chain if too much wear is present. Check sprockets for damaged bearing surfaces or splines. Check thrust washers and drive link for excessive wear or damage. Inspect 4th clutch shaft and turbine shaft for damaged bushings, splines or seals. Replace if necessary.

1. Thoroughly clean and air dry valve body. Remove each valve train, beginning with upper left hand corner. Cover bores when removing roll pins, because some valves are under spring pressure.
2. Remove blind hole roll pins with a modified drill bit. Lay valves, springs and bushings on a clean surface in the order removed. Remove servo pipe lip seals.

Clean valves, springs and bushings in solvent. NEVER use shop rags to clean valve body components. Inspect valves and bushings for scoring, nicks and scratches. Inspect springs for damaged or distorted coils. Inspect valve body casting for porosity, interconnected oil passages and damaged machined surfaces.

Reassemble valve body assembly. (Scheme 81)or (Scheme 82). Install new servo pipe lip seals.

Note. The 3-2 line control valves are matched to spacer plate. Ensure valve body parts are not mixed with parts from another transaxle.

Scheme 81

Scheme 82

Clean and air dry oil pump. Remove oil pump cover bolts. Remove vane ring, vanes and rotor. Remove seal and springs. Remove slide, slide seal support and slide seal. Remove pivot pin and roll pin. Remove 3-2 coast-down valve, spring and bore plug.

1. Inspect pump body for porosity, interconnected oil passages, or damaged inner pump area surface or machine facing. Check slide, springs, rotor and vanes for damage. Inspect slide seal, slide support and seals for damage.
2. Measure undamaged area of rotor, vane or slide to check for proper size. See «OIL PUMP COMPONENT THICKNESS CHART»(/buick/century/v-1982-1996/remont/automatic-trans/#overhaul-4t60-e). Ensure replacement parts are matched for exact fit. (Scheme 83)

Note. Oil pump components are matched sets. DO NOT mix old and new parts.

OIL PUMP COMPONENT THICKNESS CHART

1. Install vane ring onto pump pocket. Install pump slide into pump body. Install seal and support into slide.
2. Install inner priming spring into outer priming spring. Press both springs into pump body. Install "O" ring and seal ring onto slide. (Scheme 68) Install rotor into pump body. Install vanes into rotor slots, ensuring vanes are flush with top of rotor.
3. Install pump cover onto body using cover bolts. Install pump pressure screen into pump (screen has one-way tab). Install pump onto valve body assembly. Install pump attaching bolts. (Scheme 89)

Scheme 83

Thermo Element Replacement

If thermo element replacement is necessary, remove retainers, pins and thermo element. Remove plate element. For new element, set thermo pin height with Height Gauge (J-34094-A ). (Scheme 84) Install element plate. Install pin and retainer assemblies, and set height with height gauge. Install new thermo element.

Assemble oil pipe into accumulator cover. Install governor screen (closed end first) into governor feed pipe. Install oil pipes into governor retainer.

Scheme 84

Inspect servo pistons and seals for damage or cracks. DO NOT remove seals unless replacement is required. Inspect springs for damaged coils.

DO NOT interchange servo parts. Assemble spring retainer onto pin. 1-2 servo spring retainer step must face spring. Reverse servo wave spring must be installed between 2 spring retainers. Install cushion spring, servo piston and snap ring onto pin. (Scheme 67)

TRANSAXLE REASSEMBLY

Note. All selective snap ring and thrust washer measurements taken during disassembly must be rechecked at appropriate reassembly stage.

Scheme 85

Scheme 86

Scheme 87

Scheme 88

1. Install and ensure sun gear shaft, forward band, 1-2 band, reaction sun gear and reverse band drum are in place. Ensure 1-2 band anchor pins engage band, and 1-2 band assembly stop is in place.
2. Install reverse band, making sure anchor engages band. Recheck end play of final drive. See «FINAL DRIVE ASSEMBLY OVERHAUL»(/buick/century/v-1982-1996/remont/automatic-trans/#overhaul-4t60-e) under COMPONENT DISASSEMBLY & REASSEMBLY. Install thrust washer onto input shaft and hold it in position with petroleum jelly. Install sprag, roller clutch and input sun gear assembly into input clutch assembly. Clutch hubs must engage clutch plates.
3. Install input clutch roller clutch and sprag assemblies into case using Final Drive/Clutch Installer (J-33381 ). DO NOT install 2nd clutch housing, thrust bearing or thrust washer at this time.
4. Check input shaft end play. (Scheme 69) Install and tighten Aligner/Loader (J-26958-10 ). Install End Play Gauge (J-33386 ) and thrust washer. Using feeler gauge, check clearance between thrust washer and end play gauge. Clearance must be.000-.006" (.000-.152 mm). If clearance is not as specified, use different thrust washer. See «INPUT SHAFT THRUST WASHERS»(/buick/century/v-1982-1996/remont/automatic-trans/#overhaul-4t60-e). INPUT SHAFT THRUST WASHERS Washer Color Thickness: In. (mm) Orange/Green.114-.118 (2.90-3.00) Orange/Black.120-.124 (3.05-3.15) Orange.126-.130 (3.20-3.30) White.132-.136 (3.35-3.45) Blue.138-.142 (3.50-3.60) Pink.144-.148 (3.65-3.75) Brown.150-.154 (3.80-3.90) Green.155-.159 (3.95-4.05) Black.161-.165 (4.10-4.20) Purple.167-.171 (4.25-4.35) Purple/White.173-.177 (4.40-4.50) Purple/Blue.179-.183 (4.55-4.65) Purple/Pink.185-.189 (4.70-4.80) Purple/Brown.191-.195 (4.85-4.95) Purple/Green.197-.201 (5.00-5.10)
5. Install reverse reaction plate and thrust washer. Install thrust bearing with large race facing down. Install 2nd clutch assembly onto input clutch assembly. Clutch plates must engage input clutch hub, and clutch housing must engage reverse reaction drum splines.
6. Install reverse band into case, locating band on anchor pins. Install thrust washer to driven sprocket support, and hold washer in position with petroleum jelly. Install driven sprocket support into case, ensuring support lube hole aligns with hole in bottom of case.
7. If removed, install driven sprocket support assembly. Install output shaft into case. Install "C" ring onto output shaft through bottom of case. Push "C" ring onto output shaft.
8. Coat Seal Installer (J-29569-1 and J-29829-1) with petroleum jelly, and place seal installer over turbine shaft. Slide oil ring seals into position. Using Seal Sizer (J-29569-2 and J-29829-1), size seals by gently twisting sizer over seal.
9. Install thrust washer onto drive sprocket, and hold washer in position with petroleum jelly. Install sprockets and drive link onto case. Ensure colored link faces upward.
10. Install thrust washer onto driven sprocket and retain with petroleum jelly. Insert 4th clutch shaft through driven sprocket, and install clutch apply plate with identification mark facing down. Install 4th clutch plates. (Scheme 85)
11. If necessary, pry out axle seal, and tap new seal into place. Install pistons and pins into channel plate. Install springs into case. Install channel plate gaskets and modulator port gasket. Install thrust washer onto channel plate.
12. Install channel plate onto case. Channel plate lugs must align with tangs on 4th clutch plates and apply plate. (Scheme 85) Install sleeve into channel plate. Install oil reservoir baffle, detent spring and roller. Install channel plate gaskets.
13. Install and tighten channel plate bolts. (Scheme 90) Install check balls in channel plate, using petroleum jelly to retain check balls. (Scheme 86) Install converter clutch screen. Install detent spring and roller assembly.
14. Install new spacer plate/channel plate gasket onto channel plate using alignment pins. Install spacer plate onto gasket. Install new spacer plate/valve body gasket onto spacer plate. (Scheme 87)
15. Install oil pump drive shaft and converter clutch solenoid screen. Install check balls into valve body assembly; use petroleum jelly to retain check balls in place. (Scheme 88)
16. Install valve body assembly onto channel plate using alignment pins. (Scheme 91) Install servo pipes into valve body using retainer and bolt.
17. Install gaskets onto case and channel plate. Install side cover. Install accumulator pins into case. Install accumulator springs into case. Larger spring is for 3-4 accumulator.
18. Install lube oil pipe retainer spring into pocket. Install lube oil pipe retainer onto lube oil pipe and "O" ring onto retainer. Install lube oil pipe into case. Ensure pipe is installed into driven sprocket support lube hole.
19. Install spacer plate and new gaskets onto case. Install oil scavenger scoop. Install wiring. Install accumulator cover, pipes and retainer onto case as an assembly.
20. Ensure lube oil pipe is installed into final drive internal gear. Install new filter lip seal, filter and gasket into case. Install pan.
21. Install 1-2 and reverse servo return springs into proper servo bore. Assemble each servo and then install into case. Install new oil seal ring onto each servo cover. Install 1-2 and reverse servo covers into case. Install snap rings.
22. Install speed sensor. Install modulator valve into case. Install new "O" ring seal onto modulator. Install modulator into case. Install retainer and bolt. Use Converter Holding Strap (J-21366) to hold torque converter in place for installation.

Scheme 89

Scheme 90

Scheme 91

Scheme 92

Scheme 93

Scheme 94

Scheme 95

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

WIRING DIAGRAMS

Note. For WIRING DIAGRAMS, see appropriate article: GENERAL MOTORS HYDRA-MATIC 4T60-E DIAGNOSIS - 1993 GENERAL MOTORS HYDRA-MATIC 4T60-E DIAGNOSIS - 1994

WIRE HARNESS ASSEMBLY

See also:
• GENERAL MOTORS HYDRA-MATIC 4T60-E DIAGNOSIS
• OIL PUMP & VALVE BODY
• CLUTCH & BAND APPLICATION CHART
• ROAD TEST
• HYDRAULIC PRESSURE TESTS
• SYMPTOM DIAGNOSIS
• HIGH OR LOW LINE PRESSURE