Automatic Transaxle Overhaul & Testing - 4t80-e Cadillac Seville V

APPLICATION

TRANSAXLE APPLICATION

All transaxles have a nameplate attached to the rear face of transaxle case. A transaxle VIN number is also stamped into right rear surface of case. (Scheme 1)

Scheme 1

GEAR RATIOS

TRANSAXLE GEAR RATIOS

DESCRIPTION & OPERATION

Hydra-Matic 4T80-E transaxle is a fully automatic 4-speed unit utilizing a 3-element hydraulic torque converter and converter clutch.

Transaxle uses 3 gear-type pumps to supply hydraulic pressure needed for operation. A scavenge pump removes oil from lower oil pan. This oil is pumped into side oil pan. A primary oil pump takes oil from side oil pan to use for line pressure oil. A secondary oil pump takes additional oil from side oil pan to use for initial clutch apply, forced downshifts, wide open throttle and reverse gear operations.

Multiplied torque from torque converter is transferred to transaxle by a sprocket and drive link assembly. Other internal components consist of 4 multiple disc clutches, a roller clutch, 2 sprag clutches, 2 bands and 2 planetary gear sets. Final drive and differential assemblies are bolted on end of transaxle.

Transaxle electronic control system consists of 2 PCM-controlled shift solenoids, pressure control solenoid (force motor), fluid temperature sensor, pressure switch assembly, 2 speed sensors, (VSS and ISS) and a TCC lock-up control solenoid.

Note. Pressure switch assembly may also be referred to as Transaxle Fluid Pressure (TFP) sensor.

LUBRICATION

Note. See appropriate SERVICING - A/T article.

TROUBLE SHOOTING

Note. Transaxle malfunctions may be caused by poor engine performance, improper adjustments, fluid condition or failure of hydraulic, mechanical or electronic components. Ensure all concerns have been properly checked prior to transaxle overhaul. See appropriate DIAGNOSIS article.

TORQUE CONVERTER

A visual inspection of torque converter may reveal converter is Blue from overheating. Stator roller clutch can be checked by inserting 2 fingers into splined inner race of roller clutch and attempting to turn race in both directions. Inner race should turn freely clockwise, but should not turn or should be difficult to turn counterclockwise.

TRANSAXLE CASE

Remove torque converter, turbine shaft "O" ring, oil pump drive shaft, vehicle speed sensor and oil cooler fitting from extension housing. While holding servo cover in place, remove 4th servo from case. Do not allow servo cover to tilt during removal or case damage may occur.

FINAL DRIVE CARRIER ASSEMBLY & END PLAY CHECK

1. Use Dial Indicator Post (J-25025-7A) and Dial Indicator (J-8001-3) to check end play. Pry up on speed sensor rotor through vehicle speed sensor hole. End play should be.006-.026" (.15-.65 mm). (Scheme 2) Record this measurement for reassembly.
2. Remove case extension, thrust washer, bearing and seal. Remove scavenge tube and seal from transaxle case. Lock parking gear with park actuator. Remove 4 differential bolts and differential carrier.
3. Push on output shaft and remove snap ring. Remove left-side differential gear and remove output shaft from front end of transaxle. Remove final drive carrier, thrust bearing, final drive sun gear and internal gear.

Scheme 2

LOWER TRANSAXLE ASSEMBLY

Remove lower oil pan and oil scavenge screens. Disconnect manual valve link and wiring harness connectors. Remove oil transfer plate. Leave specified bolts in assembly to hold lower control valve and accumulator assembly together. (Scheme 3) Remove control valve and accumulator cover assembly.

Scheme 3

INPUT SHAFT END PLAY CHECK

Install Input Shaft End Play Fixture (J-39686) to front side of transaxle. Ensure "J" tab on fixture rests on input shaft. Arrow on tab should have a 90 degree orientation. Washer must rest flat on case cover seal. Rotate threaded shaft clockwise until shaft is tight. Leave enough space for collar. Insert collar. Mount Dial Indicator Post (J-25025-7A) and Dial Indicator (J-8001-3) to check end play. Push down on handle to raise input shaft. End play should be.004-.033" (.10-.85 mm). (Scheme 4) Record this measurement for reassembly.

Scheme 4

SIDE COVER, OIL PUMP & UPPER VALVE BODY

1. Remove side cover, filter and seals. Disconnect wiring harness from fluid temperature sensor, pressure control solenoid, TCC solenoid and case connector. Remove wiring harness.
2. Remove oil pump assembly cover bolts. (Scheme 37) Remove pump assemblies. Remove upper valve body and separate gasket and spacer plate. Remove 2 check balls between spacer plate and case cover. Remove case cover and gaskets from transaxle case.

DRIVE LINK

Note. See COMPONENT DISASSEMBLY & REASSEMBLY for exploded views of all internal components. For thrust washer, thrust bearing and seal locations, refer to appropriate illustration. (Scheme 40)or (Scheme 41).

1. Remove thrust washers from sprockets. Grasp drive link chain above drive sprocket and pull toward transaxle case. Measure drive link chain-to-case clearance. If clearance is less than.50" (12.7 mm), replace drive link chain.
2. Mark position of drive link chain for reassembly reference. Noise may occur if chain is not installed in same direction as removed. Pry up driven sprocket. If necessary, tap on end of turbine shaft using plastic hammer. Remove turbine shaft and drive sprocket, driven sprocket and drive link chain together as an assembly. (Scheme 5)
3. Remove drive sprocket and driven sprocket supports from transaxle case. (Scheme 6) Ensure scavenge tube seal remains in support. If not, check support for damage. Remove input speed sensor and wiring harness.

Scheme 5

Scheme 6

CLUTCH & BAND ASSEMBLIES

1. Remove 2nd clutch plate assembly. (Scheme 14) Remove reverse clutch support thrust washer. Remove reverse clutch housing and 2nd sprag assembly. (Scheme 12) Remove 4th band. Holding 3rd clutch housing by input shaft, remove 3rd clutch and reaction carrier assemblies. (Scheme 9) Remove reaction carrier shell. (Scheme 34)
2. Move manual control shaft from "P" position. Remove parking pawl, spring and pivot pin assembly. Remove 2 forward and coast clutch support bolts from transaxle case. (Scheme 7) Remove oil cooler return fitting from forward and coast clutch support.
3. Using Forward/Coast Clutch Puller (J-39053), remove clutch assemblies. (Scheme 7) Remove low-reverse band and support fretting ring. (Scheme 17)
4. Remove detent spring. Remove detent lever pivot arm. While holding detent lever in place, remove manual shaft nut. Remove detent lever and actuator rod. Remove manual shaft assembly and case seals. (Scheme 8)

Scheme 7

Scheme 8

Cleaning & Inspection

Clean transaxle case thoroughly with solvent and 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.

Disassembly & Inspection

1. Remove snap ring, input sun gear and input sun gear thrust bearing. Remove reaction carrier assembly. Remove reaction sun gear shell assembly.
2. Remove 3rd clutch hub. Remove snap ring and backing plate. Remove clutch plates. Compress spring assembly and remove snap ring and retainer. Remove spring and retainer assembly and piston. Remove seal rings from 3rd clutch housing (if necessary). (Scheme 9)
3. Check 3rd clutch housing for plugged feed holes. Inspect reaction carrier and sun gear for damaged teeth, scoring or warpage. Check thrust bearing for damage.
4. Check reaction carrier pinion gear end play. Using feeler gauge, measure end play between reaction carrier housing and planetary pinion gear. End play should be.004-.035" (.10-.89 mm). (Scheme 10) Check for damage to reaction carrier internal gear. (Scheme 9)

Reassembly

1. Lubricate seal rings. Using seal ring expander, install both seal rings (if removed). Using Seal Ring Sizer (J-34741-3), compress seal rings and leave tool in place until input housing is installed.
2. Apply petroleum jelly to 3rd clutch piston seals. While rotating, insert piston into 3rd clutch housing. Install spring and retainer assembly. Place retainer on top of spring and retainer assembly. Using appropriate compressor, compress spring and retainer assembly and install snap ring.
3. Install apply plate. Install 4 friction plates and 3 steel plates, beginning with friction and alternating with steel plate. (Scheme 9) Install backing plate with stepped side up. Install snap ring, thrust washer and 3rd clutch hub assembly.
4. Install thrust bearing with rolled inner lip facing clutches. Install reaction sun gear and shell assembly. Install thrust bearing inside reaction carrier, and install reaction carrier assembly.
5. Install reaction carrier thrust bearing with Black side facing reaction carrier. Install input sun gear and snap ring. Using petroleum jelly, attach selective thrust washer and thrust bearing to top of clutch housing. Install 3rd clutch and reaction carrier in driven sprocket support. Apply 50-60 psi (3.5-4.2 kg/cm 2 ) to appropriate passage to ensure proper operation of 3rd clutch. (Scheme 11)

Scheme 9

Scheme 10

Scheme 11

Inspection

DO NOT wash 4th band in solvent. Inspect 4th band assembly for heat damage, lining cracks and separation. Check band stop for damage and replace if necessary.

Remove snap ring and disassemble clutch plates. Compress spring assembly, and remove snap ring and retainer seat. Remove spring and retainer assembly and piston. (Scheme 12) If necessary, remove 2nd sprag. Spiral snap ring must be replaced if removed from 2nd sprag. Check clutch housing for plugged feed holes. Inspect clutches for wear and piston for cracks or damaged check ball. Inspect 2nd sprag for damage.

1. Install NEW seals on reverse clutch piston. Apply petroleum jelly to seals, and install clutch piston into housing. Install spring and retainer assembly. Install retainer seat. Using appropriate compressor, install snap ring.
2. Install Belleville plate. Install 2 steel plates and 2 friction plates, beginning with steel plate and alternating with friction plate. Install apply plate with stepped side up. Install snap ring. Install 2nd clutch outer race thrust washer.
3. Install sprag clutch into outer race. Ensure 2nd sprag rotates in correct direction. With sprag assembled on top of reverse clutch and race housing, hold housing and ensure 2nd sprag race turns clockwise. (Scheme 13) Install sprag clutch retainer. Install NEW 2nd sprag spiral snap ring, if removed. Ensure spiral snap ring tabs lock into place and is fully seated.

Scheme 12

Scheme 13

1. Position clutch plates on bench. Compress spring assembly, and remove snap ring. Remove spring assembly and piston from driven sprocket support. (Scheme 14) Remove 3rd clutch exhaust valve from driven sprocket support.
2. Check driven sprocket support for plugged feed holes or damage. Inspect clutches for wear and piston for cracks or damaged check ball. Inspect 3rd clutch exhaust valve for scoring.

Apply petroleum jelly to piston seals. While rotating, insert piston into driven sprocket support. Install spring and retainer assembly. Compress spring assembly, and install snap ring. Install backing plate with flat side up. Install 4 friction plates and 4 steel plates, beginning with a friction plate and alternating with steel plates. Install apply plate and wave plate. Install 3rd clutch exhaust spring and valve into driven sprocket support.

Scheme 14

Remove snap ring, parking lock gear and thrust bearing. Remove forward clutch support assembly with low-roller clutch. (Scheme 17) Separate clutch housing from coast clutch hub and thrust washers. Remove final drive sun gear shaft. (Scheme 15)- (Scheme 17). Using feeler gauge, measure input carrier housing-to-pinion gear end play. End play should be.003-.035" (.08-.89 mm). (Scheme 18)

1. Install input carrier assembly onto reaction internal gear with snap ring. Install thrust washer/bearing onto input carrier. Install input internal gear flange onto gear with snap ring. Install thrust washer onto flange.
2. Install forward clutch sprag assembly. Ensure direction of cage lip is correct (facing internal gear). (Scheme 16) Ensure forward sprag rotates in counterclockwise direction. (Scheme 19) Install thrust washer onto coast clutch hub. Install coast clutch hub onto flange with snap ring. Install thrust washer/bearing onto coast clutch hub.

Scheme 15

Scheme 16

Disassemble clutch support. Remove and discard oil seal rings and oil cooler return seal. (Scheme 17) Inspect all parts for damage or wear. Replace bushing if worn.

Install NEW seals on clutch support. Install low-roller clutch. (Scheme 17) Turn counterclockwise as far as possible. Ensure tabs on clutch rest on face of clutch support. (Scheme 20) Ensure low-roller clutch turns in correct direction, and locks in opposite direction. (Scheme 21)

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

1. Remove snap ring from forward/coast clutch housing. Remove backing plate, forward clutch, Belleville, coast clutch and apply plates from housing. Compress spring assembly and remove snap ring.
2. Remove coast clutch piston, apply ring, forward clutch piston and seals. (Scheme 15) Inspect clutches for wear and piston for cracks or damaged check ball.

Scheme 22

1. Place NEW seals on forward clutch piston, and install in housing. Install forward clutch apply ring. Place NEW seals on coast clutch piston, and install in housing. Install spring assembly. Using appropriate compressor, apply pressure to spring assembly and install snap ring. Install backing plate, forward clutch, Belleville, coast clutch and apply plates in reverse order. (Scheme 15) Install clutch assembly snap ring.
2. Install thrust bearing to back side of forward/coast clutch housing. Connect forward clutch support to forward/coast clutch housing. Assemble coast clutch hub with thrust bearing, input internal gear and flange into forward/coast clutch housing. (Scheme 16) NOTE: When splines of coast clutch hub and forward sprag outer race are properly engaged, input carrier will drop below forward/coast clutch support hub. Ensure a dull metal sound is heard during engagement. Distance from top edge of forward/coast clutch housing to top edge of input internal gear should be about.886" (22.50 mm). (Scheme 22)
3. Install input carrier and reaction internal gear with thrust washer onto input internal gear. Install final drive sun gear shaft. Install thrust bearing and parking lock gear. Install snap ring. (Scheme 16)and (Scheme 17).

1. Inspect final drive internal gear for damaged teeth, worn bearing surfaces, or damage to differential and pinion gears. Inspect sun gear, thrust bearings and speed sensor ring gear for wear or damage.
2. Check final drive carrier pinion gears for excessive end play. Measure end play between carrier and pinion gear thrust washer. End play should be.008-.012" (.20-.30 mm). (Scheme 18) Replace final drive carrier if clearance is not within specification.
3. Using pin punch, drive differential pinion shaft retaining pin from carrier. Remove pinion shaft, pinion gears and thrust washers. (Scheme 23) Remove side gears and thrust washers.
4. Remove sun gear-to-carrier thrust bearing. Using screwdriver, pry final drive sun gear from final drive carrier. Inspect all parts for damage or abnormal wear. Inspect final drive sun gear shaft for damaged splines or journals.

1. Assemble differential side gears and thrust washers into carrier. Replace snap ring on right side gear output shaft. Using petroleum jelly, position thrust washers onto pinion gears. Assemble pinion gears and washers into carrier.
2. Rotate pinion gears into position, and install pinion shaft. Tap retaining pin into position using plastic hammer. Assemble remaining thrust washers, spacers and snap rings. Install final drive sun gear seal into sun gear with seal lip facing forward clutch. Install sun gear.

Scheme 23

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

Disassembly, Inspection & Reassembly

1. Remove accumulator housing from channel plate. Remove 4 check balls. Remove accumulator spring from channel plate. Remove transaxle pressure switch assembly from lower control valve assembly. (Scheme 25)
2. Remove "E" clips from accumulator shafts on top side of accumulator housing. (Scheme 24) Remove 1-2 and 3-4 accumulator assemblies (piston, "O" ring, spring and shaft).
3. Remove cover from accumulator housing. Remove forward and reverse accumulator assemblies. Check all parts for wear or damage and replace as necessary. Lubricate all NEW seals with ATF. To reassemble, reverse disassembly procedure.

Scheme 24

Disassembly

Thoroughly clean and air dry valve bodies. Remove check balls. Remove each valve train. Position valves, springs and bushings on clean surface in order removed. Remove solenoids, sensor, screens, low-reverse servo and accumulator assemblies. (Scheme 26)and (Scheme 27).

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 assemblies. (Scheme 26)and (Scheme 27). Using Guide Pins (J-39630-1) and (J-39068-2), assemble lower valve body to channel plate. (Scheme 28)- (Scheme 30). Ensure NEW pressure control solenoid filter and oil pressure screen is used. After assembly, ensure all valves move freely in respective bores.

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Scheme 29

Scheme 30

1. Clean and air dry oil pump. Remove secondary pump body from primary/scavenge pump assembly. These components are held together tightly by 2 roll pins. Remove oil pump shaft and secondary pump gears.
2. Remove scavenge pump body and gears from scavenge pump cover. Remove primary pump body and gears from scavenge pump cover. (Scheme 32) Remove retainer pin, ball seat and ball. Remove retainer pin, pressure regulator valve and sleeve and boost valve assembly. (Scheme 31)

Inspect pump body for porosity, interconnected oil passages, or damaged inner pump area surface or machine facing. Check oil pump gears for damage. Check oil pump shaft and thrust washer for wear or damage.

Install valve train assemblies into pump body. Install and align oil pump gears with punch marks up. Ensure oil pump shaft end with 4 notches is installed into secondary pump. Assemble scavenge oil pump cover and secondary oil pump body to scavenge oil pump body.

Scheme 31

Scheme 32

LOW-REVERSE SERVO & 4TH SERVO

For low-reverse servo disassembly procedure. See VALVE BODIES . For 4th servo disassembly procedure, see TRANSAXLE CASE under TRANSAXLE DISASSEMBLY.

TRANSAXLE REASSEMBLY

Note. All selective snap ring and thrust washer measurements taken during disassembly must be rechecked at appropriate reassembly stage. For thrust washer thrust bearing and seal location and identification, refer to appropriate illustration. (Scheme 40)or (Scheme 41).

Scheme 33

Scheme 34

Scheme 35

Scheme 36

Scheme 37

1. Install manual shaft, detent lever assembly and parking pawl, if removed. (Scheme 8) Install drive sprocket support, input speed sensor and wiring harness. (Scheme 6) Install torque converter seal.
2. Install low-reverse band and ensure anchor engages band. Install support fretting ring with open end toward lower oil pan. Install oil cooler return fitting "O" ring to coast and forward clutch assembly. Using Forward/Coast Clutch Puller (J-39053), install coast and forward clutch assembly into case. (Scheme 7) Ensure anchor holes in support align with holes in case.
3. Install final drive internal gear with groove up. Install snap ring with flat side down and open end in actuator rod area. Rotate support counterclockwise against spline. (Scheme 33)
4. Install reaction carrier shell into forward clutch housing with small teeth facing down. Install 3rd clutch housing and reaction carrier assembly. Install input shaft selective thrust washer and thrust bearing on 3rd clutch housing. (Scheme 4) Install 4th band and reverse clutch assembly. (Scheme 34) Ensure band pin seat engages servo pin. Install reverse clutch housing and thrust washer.
5. Install seal on drive sprocket support. Using Sizer (J-39064-2), size seal. Install backing plate, 2nd clutch plates, apply plate and wave plate. (Scheme 14)
6. Place scavenge tube seal on driven sprocket support and install driven sprocket support. Install drive chain (in same direction as removed) to drive sprocket support. Tap sprockets until seated. Place thrust washers on sprockets.
7. Install island gasket and case cover gasket. (Scheme 36) Install case cover allowing wiring harness connector to pass through opening in case cover. Install bolts in correct position and hand tighten only.
8. Check input shaft end play. (Scheme 4) Install Input Shaft End Play Fixture (J-39686) to front side of transaxle. Ensure "J" tab on fixture rests on input shaft. Mount Dial Indicator Post (J-25025-7A) and Dial Indicator (J-8001-3) to check end play. Push down on handle. End play should be.004-.033" (.10-.85 mm). Input shaft thrust washers range in thickness from.089" (2.26 mm) to.195" (4.95 mm) in increments of.012" (.30 mm).
9. Tighten case cover bolts and studs in a crisscross pattern to specification. See «TORQUE SPECIFICATIONS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-overhaul-testing-4t80-e__torque-specifications). Install 2 check balls. (Scheme 36) Install upper valve body. (Scheme 37) Tighten bolts beginning with center bolts and working toward outside bolts to specification. See «TORQUE SPECIFICATIONS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-overhaul-testing-4t80-e__torque-specifications). Install side filter.
10. Install TCC solenoid and transaxle pressure control solenoid. Install oil pump assembly. Tighten bolts beginning with center bolts and working toward outside bolts to specification. See «TORQUE SPECIFICATIONS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-overhaul-testing-4t80-e__torque-specifications). Install oil pan and tighten bolts in a star pattern. Install 4th servo. (Scheme 35) Ensure tab on servo piston aligns with slot in case (some models).
11. Ensure low-reverse band is installed in correct position. Install lower valve body and channel plate. (Scheme 38) Install bolts and tighten by hand. Remove shim stock.
12. Install oil transfer plate and hand tighten bolts. (Scheme 38) Connect wiring harness and manual valve. Tighten channel plate and oil transfer plate bolts in a crisscross pattern to specification. See «TORQUE SPECIFICATIONS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-overhaul-testing-4t80-e__torque-specifications). Install scavenge screens. (Scheme 35) Install lower oil pan and gasket and tighten bolts to specification in correct sequence. (Scheme 39)
13. Assemble and install final drive, output shaft and differential carrier. Engage parking pawl to hold final drive unit. Tighten differential carrier bolts.
14. Install scavenge tube and seal. (Scheme 35) Install selective thrust washer and roller thrust bearing onto output shaft. Install extension housing and hand tighten bolts.
15. Using Dial Indicator Post (J-25025-7A) and Dial Indicator (J-8001-3), check end play. Pry up on speed sensor rotor through speed sensor hole. End play should be.006-.026" (.15-.65 mm). (Scheme 2)
16. If necessary, adjust end play with selective final drive-to-case thrust washer. See «FINAL DRIVE-TO-CASE SELECTIVE THRUST WASHER IDENTIFICATION»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-overhaul-testing-4t80-e) table. Tighten extension housing bolts. Install oil cooler return fitting to forward and coast clutch support. Install axle seals, oil pump drive shaft, torque converter and vehicle speed sensor.

FINAL DRIVE-TO-CASE SELECTIVE THRUST WASHER IDENTIFICATION

Scheme 38

Scheme 39

Scheme 40

Scheme 41

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

TRANSAXLE SPECIFICATIONS

TRANSAXLE SPECIFICATIONS

See also:
• COMPONENT DISASSEMBLY & REASSEMBLY
• TRANSAXLE CASE
• TORQUE SPECIFICATIONS