Automatic Transmission Overhaul - 4l80-e GMC Suburban I

APPLICATION

TRANSMISSION APPLICATIONS

IDENTIFICATION

All transmissions have a metal identification plate attached to rear face of transmission case. (Scheme 27)

Scheme 27

DESCRIPTION

Hydra-Matic 4L80-E transmission is a fully automatic 4-speed unit consisting primarily of a hydraulic torque converter and converter clutch. Transmissions have dual stators inside torque converter. Transmission uses a gear-type oil pump to supply all hydraulic pressure needed for operation.

Other internal parts include the following: 5 multiple disc clutches, a roller clutch, a sprag clutch, 2 bands and 3 compound planetary gear sets. (Scheme 28)

Hydra-Matic 4L80-E also uses 2 electronic shift solenoids controlled by Powertrain Control Module (PCM) or Transmission Control Module (TCM). Transmission uses a electronic speed sensor(s) instead of a mechanical governor.

Scheme 28

LUBRICATION

See appropriate AUTOMATIC TRANSMISSION SERVICING article in the TRANSMISSION SERVICING section.

ON-VEHICLE SERVICE

The following components can be serviced without removing transmission from vehicle

1. Converter-To-Flexplate Bolts
2. Filler Pipe
3. Front Servo
4. Rear Servo
5. Rear Extension Housing
6. Shift Control Cable
7. Solenoids
8. Speedometer Driven Gear & Seal
9. Speed Sensor
10. Transmission Pan & Filter
11. Valve Body
12. Wiring Harness
13. 3-4 Accumulator Assemblies

VALVE BODY

See OIL PUMP & VALVE BODY under TRANSMISSION DISASSEMBLY.

OIL COOLER FLUSHING

1. If available, fill line flusher with solution and install Oil Cooler and Line Flusher (J-35944) to top transmission cooler line on transmission. Follow manufacturer's instructions to flush oil cooler and cooler lines.
2. If flusher tool 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.

ADJUSTMENTS

See appropriate AUTOMATIC TRANSMISSION SERVICING article in the TRANSMISSION SERVICING section.

TROUBLE SHOOTING

Note. For electrical trouble shooting, see 4L80-E ELECTRONIC CONTROLS article. For additional trouble shooting, see CLUTCH & BAND APPLICATION CHART (4L80-E) under CLUTCH & BAND APPLICATION

QUICK CHECK

1. Check level and condition of transmission fluid. Check PCM or TCM memory for any stored trouble codes. See 4L80-E ELECTRONIC CONTROLS article. If no trouble codes are present, go to next step. If codes are present, diagnose and repair all computer-related trouble codes. Clear PCM or TCM trouble code memory.
2. Perform road test. See «ROAD TEST»(/gmc/suburban/i-1992-1999/remont/automatic-trans/#automatic-transmission-overhaul-4l80-e__road-test) under TESTING. During road test, record shift points. If shift point timing or shifting is incorrect, go to AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1995 article or AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1996 article.
3. If shift(s) is too harsh or too soft, see «HYDRAULIC PRESSURE TESTS»(/gmc/suburban/i-1992-1999/remont/automatic-trans/#automatic-transmission-overhaul-4l80-e__hydraulic-pressure-tests) under TESTING. For specific complaints, see appropriate condition(s) listed under «SYMPTOM DIAGNOSIS»(/gmc/suburban/i-1992-1999/remont/automatic-trans/#automatic-transmission-overhaul-4l80-e__symptom-diagnosis) .

SYMPTOM DIAGNOSIS

Note. Models with gasoline engines use Powertrain Control Module (PCM) computer. Models with Diesel engines use Transmission Control Module (TCM) computer. These computers control TCC, pressure control solenoid (hydraulic pressure), 1-2 shift solenoid ("A") and 2-3 shift solenoid ("B").

Fluid Flowing Out Of Vent Or Foaming

Transmission overfilled. Fluid contaminated with antifreeze or engine overheating. Filter not seated. Cross-channel leak allowing pressure to leak in to vent area of pump cover.

Transmission Overheats

Low fluid or blocked radiator. TCC stuck in apply or release. Broken TCC valve spring. Cross channel leakage in pump cover. Pressure regulator stuck in high demand. Blocked oil cooler. Problem with converter limit valve assembly. Loss of fluid. Problem with stator(s) or turbine seals.

Reduced Internal Lubrication

Cross channel leakage in pump cover. Pressure regulator valve stuck in high demand. Damaged oil pump mounting gasket. Stuck closed converter limit valve assembly (under heavy load).

High Or Low Line Pressure

Incorrect fluid level. Oil pump assembly seals or gears damaged. Pump drive shaft damaged. Pressure regulator valve spring damaged, pressure regulator valve nicked or scored. Pressure relief valve spring damaged. Pump cover leaking (bolts loose). Pressure control solenoid off or on at all times. Loose connection at PCM or TCM.

Inoperative In Drive

1. Low fluid level. Low fluid pressure. Manual linkage misadjusted or disconnected. Damaged torque converter. Leaking or damaged transmission case seals or gaskets. Damaged oil pump drive shaft or pump assembly. Broken bearing, pinion or carrier. Roller clutch damaged or locked.
2. Piston or seal damaged in forward clutch assembly. Forward clutch assembly clutch plates burned or missing, or check ball capsule leaking or missing. Burned reaction plate (due to lack of lubrication), broken snap ring or worn gear teeth.
3. Rear gear set assembly pinions, internal ring gear or sun gear damaged. Main shaft damaged. Parking pawl spring broken. Turbine shaft ball not seating.

Vehicle Moves Forward In "N"

Mispositioned or stuck manual valve. Problem with forward clutch assembly.

Engine Stall

Seized forward clutch, 4th clutch or overrun clutch assembly. TCC stuck on or dragging.

No Torque In Reverse & 3rd

Broken forward clutch hub, housing or snap ring.

Locked In Park

Damaged parking pawl; binding, weak spring or stretched rod.

Vehicle Moves In Park

Manual linkage damaged or disconnected. Broken parking pawl spring, parking pawl or parking pawl gear assembly. Park actuator spring damaged.

Slips In Reverse

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

No Reverse

Low fluid pressure. Reverse servo not correctly assembled, piston or seal damaged, or incorrect apply pin. Damaged rear band. Direct clutch assembly clutch plates burned or missing, or check ball capsule leaking or missing.

Slips In "D"

Low fluid level. Low fluid pressure.

No 1st Gear In "D4"

Low roller assembly not attached or race broken. Broken center support race or splines. Damaged case near center support. Center support snap rings not seated.

No 1st Gear In "D2" Or "D3"

Low roller assembly not attached or race broken. Broken center support race or splines. Damaged case near center support. Center support snap rings not seated. Stuck front band.

No 1st Gear In "D1"

Low roller assembly not attached or race broken. Broken center support race or splines. Damaged case near center support. Center support snap rings not seated. Broken housing, or mispositioned or broken rear band anchor pin. Misaligned detent lever.

No 1-2 Shift In "D4" (1st Gear Only)

Output or input speed sensor reads zero. Sun gear splines damaged or missing.

1st & 2nd Gear Only

Solenoid "B" stuck off or not connected to PCM or TCM. Dirt in filter, leaking "O" ring or no supply voltage to solenoid "B". Stuck 2-3 shift valve.

1st & 4th Gear Only (Manual 2nd & 3rd Only)

Solenoid "A" stuck off. Dirt in filter, PCM or TCM not grounded, leaking "O" ring, no supply voltage to solenoid "A" or wire disconnected. Stuck 1-2 shift valve.

Late 1-2 Shift

Problem with input and/or output speed sensor(s). Faulty Digital Ratio Adapter (DRAC on 2WD only). Incorrect PROM calibration.

No Engine Braking In "D1"

Problem with rear band assembly. Damaged main or output shafts.

No 2nd Gear

Intermediate clutch feed cup plug missing. Problem with intermediate clutch and center support assembly. Damaged intermediate sprag. Broken direct clutch housing or snap ring.

2nd Gear Only

Check for possible Diagnostic Trouble Codes (DTCs).

No Torque In 2nd

Worn or damaged intermediate sprag.

Starts In 2nd Gear

Seized intermediate clutch plates. Problem with direct clutch or center support assemblies. Stuck 1-2 shift valve. PCM- or TCM-related problem.

No 2nd Gear Braking In "D2"

Problem with direct clutch housing or front band assemblies.

No Engine Braking In "D2"

Problem with rear gear set assembly. Damaged main or output shafts.

No Overrun Braking In "D2"

Problem with overrun clutch or reaction sun gear assemblies.

No 1st Gear In "D3"

Low roller assembly not attached or race broken. Broken center support race or splines. Damaged case near center support. Center support snap rings not seated. Applied front band.

No 2nd Gear In "D3"

Intermediate clutch feed cup plug missing. Problem with intermediate clutch and center support assembly. Damaged intermediate sprag. Broken direct clutch housing or snap ring.

No 3rd Gear In "D3"

Direct clutch feed cup plug missing. Problem with direct clutch and center support assembly. Broken direct clutch housing or snap ring. Solenoid "B" stuck off. Dirt in filter, PCM or TCM not grounded, leaking "O" ring, no supply voltage to solenoid "B" or wire disconnected. Stuck 2-3 shift valve. PCM or TCM problem.

Starts In 3rd Gear

Seized forward clutch or oil holes in driving hub plugged. Damaged or seized direct clutch assembly.

No Engine Braking In "D3"

Damaged main shaft or main shaft bushing.

2nd & 3rd Gear Only

Stuck 1-2 shift valve. Solenoid "A" off. Dirt in filter, PCM or TCM not grounded, leaking "O" ring, no supply voltage to solenoid "A" or wire disconnected.

No 4th Gear

Problem with 4th clutch or overrun clutch related assemblies. 2-3 shift valve stuck. Solenoid "B" off. Dirt in filter, PCM or TCM not grounded, leaking "O" ring, no supply voltage to solenoid "B" or wire disconnected.

Starts In 4th Gear

Solenoid "B" stuck on. Dirt in filter, PCM or TCM signal wire grounded.

Note. Digital Ratio Adapter (DRAC) receives signals from electronic speedometer and sends them to PCM/TCM.

Incorrect Shift Points

Problem related to PCM or TCM signal inputs from TPS, speed sensors or pressure switch assembly. Faulty Digital Ratio Adapter (DRAC on 2WD only). Incorrect tire size, axle ratio or PROM.

Harsh Shifts

High or low line pressures. Pressure control solenoid stuck off. Accumulator piston seals damaged or piston springs missing. Accumulator cover bolts improperly tightened or gaskets mispositioned. Missing check balls. Incorrect PROM calibration.

Harsh Shifts ("D" To "R")

Blocked direct lube exhaust. Forward clutch spring not working. Direct clutch snap ring broken or not seated. Plugged direct clutch check ball.

Harsh Shifts (3-4 Shift)

Binding 4th clutch spring assembly. Plugged air bleed hole. 4th clutch case bolt blocking oil feed hole.

Harsh Shifts (4-3 Shift)

4th clutch snap ring not seated. 4th clutch spring assembly not working. Plugged 4th clutch housing cup plug. 4th clutch case bolt blocking oil feed hole. Blocked direct lube exhaust port.

Harsh Shifts ("D4" To "D3", "D2" Or "D1")

Overrun clutch return spring assembly not working. Plugged overrun clutch housing check ball. Snap ring not seated.

Soft Shifts

Low line pressures. Pressure control solenoid stuck on. Accumulator piston seals damaged or piston springs missing. Accumulator cover bolts improperly tightened or gaskets mispositioned. PCM or TCM failure. Incorrect PROM calibration.

Soft Shift (Into "R")

Plugged direct clutch oil feed. Blocked direct lube exhaust port.

Soft Shift (R To "D")

Direct clutch spring not working, large snap ring not seated or plugged check ball.

Soft Shift (2-1)

Intermediate clutch spring assembly not working. Center support snap ring not seated. Center support air bleed blocked.

Soft Shift (2-3)

Plugged direct clutch oil feed. Blocked direct lube exhaust port.

Soft Shift (3-2)

Direct clutch spring not working, small snap ring not seated or plugged check ball.

Soft Shift ("D3" To "D2")

Missing check ball. Incorrect orifice sizes.

No "D2" To "D1" Shift

Broken or disconnected rear band. Incomplete travel of detent lever.

No "D3" To "D2" Shift

Broken or disconnected front band.

No Converter Clutch Apply

Verify proper PCM or TCM operation and vehicle wiring. Damaged wiring harness or pinched wires. Brake switch not working or misadjusted. Solenoid inoperative. Oil pump valve assembly converter clutch shift valve stuck. Converter clutch apply valve stuck. Leaking solenoid "O" ring or blocked screen. Inspect torque converter for external leaks at hub weld area, or unbalanced or contaminated fluid. Turbine shaft seals damaged. Oil pump drive shaft seal damaged. Converter clutch valve release exhaust orifice cup plug not seated or damaged.

TCC Does Not Release

PCM or TCM-controlled TCC solenoid stuck on or does not exhaust. Control valve assembly converter clutch apply valve stuck in apply position. Faulty PCM or TCM.

TCC Apply Soft Or Slipping

Leaking turbine shaft seals. Worn oil pump body bushing. Leaking oil hole transfer cup plug. Faulty TCC solenoid. Low fluid pressure.

Incorrect TCC Apply Or Release

Incorrect output speed sensor, engine speed or throttle position sensor signal. Faulty PCM or TCM. Faulty pressure switch or temperature sensor. Incorrect coolant or transmission temperature (Diesel engine) signal. Problem with Digital Ratio Adapter (DRAC on 2WD only). Faulty brake switch circuit or ignition module (gasoline vehicles) or faulty tachometer (Diesel vehicles).

CLUTCH & BAND APPLICATION

CLUTCH & BAND APPLICATION CHART (4L80-E)

ELECTRONIC SELF-DIAGNOSTICS & ELECTRONIC TESTING

Note. See AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1995 article or AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1996 article.

Note. Models with gasoline engines use Powertrain Control Module (PCM) computer. Models with Diesel engines use Transmission Control Module (TCM) computer. These computers control hydraulic line pressure, shift solenoids "A" and "B", and TCC.

ROAD TEST

Note. Shift speed charts reference throttle position angle instead of minimum or wide open throttle position. This measurement is more accurate. A scan tool should be used to monitor throttle position angle. 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 shift speed charts as a reference for correct shift speeds. (Scheme 29)-5. Also note when Torque Converter Clutch (TCC) engages while in 3rd gear or overdrive. NOTE: Ensure TCC engages in 3rd gear or overdrive during the following steps. Transmission has a Pulse Width Modulated (PWM) solenoid, which may make TCC engagement point hard to detect. If necessary, a scan tool may be used to indicate TCC and shift solenoid operation.
2. At vehicle speeds of 40-50 MPH, quickly depress accelerator to half open position (part throttle detent downshift). TCC should release, solenoid "A" turns off, and transmission 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, solenoids "A" and "B" turn off, and transmission should immediately downshift to 2nd gear.
4. At vehicle speeds of 40-55 MPH, release accelerator pedal while moving gear selector to "3" (3rd gear) position. TCC should release, transmission should downshift to 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, transmission should downshift to 2nd gear immediately, and engine braking should slow vehicle.
6. Move gear selector to "D" (overdrive) position, and accelerate to 30 MPH. Release accelerator pedal while moving gear selector to "1" (1st gear) position. TCC should release, transmission 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. The TCC should release. Note speeds at which vehicle downshifts. (Scheme 29)through (Scheme 31).

Gear Selector Position "3" (3rd Gear)

With vehicle stopped, move gear selector to "3" (3rd gear) position. Steadily increase throttle pressure to accelerate vehicle. Note speeds at which vehicle shifts into 2nd and 3rd gears. (Scheme 29)through (Scheme 31). Ensure 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 35 MPH. Transmission 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 20 MPH. Transmission should not upshift, and TCC should not engage.

Gear Selector Position "R" (Reverse)

With vehicle stopped, move gear selector to "R" (Reverse) position. Verify 1-2 shift solenoid is on and 2-3 shift solenoid is off.

Scheme 29

Scheme 30

Scheme 31

HYDRAULIC PRESSURE TESTS

1. Before performing hydraulic pressure test, check fluid level and condition. Check manual control linkages for correct adjustment, and ensure engine is properly tuned.
2. Connect scan tool to Data Link Connector (DLC). Apply parking brake and start engine. Check for stored trouble codes. If trouble codes are present, diagnose as necessary. See 4L80-E ELECTRONIC CONTROLS - 1995 article in the TRANSMISSION SERVICING SECTION or 4L80-E ELECTRONIC CONTROLS - 1996 article. Turn engine off. Connect oil pressure gauge to line pressure test port. (Scheme 32)
3. Start engine and warm to normal operating temperature. With vehicle in Reverse, line pressure should be 67-324 psi (462-2234 kPa). With vehicle in Park, Neutral or Drive, line pressure should be 35-171 psi (241-1179 kPa).
4. Shift transmission into Park. Access Pressure Control Solenoid (PCS) test on scan tool. Increase DESIRED PCS in 0.1 amp increments and read corresponding line pressure on oil pressure gauge. Allow pressure to stabilize for 5 seconds after each current change. Compare readings to «LINE PRESSURE SPECIFICATIONS»(/gmc/suburban/i-1992-1999/remont/automatic-trans/#automatic-transmission-overhaul-4l80-e). If pressure readings are not as specified, and no trouble codes are present, internal malfunction exists. See «TROUBLE SHOOTING»(/gmc/suburban/i-1992-1999/remont/automatic-trans/#automatic-transmission-overhaul-4l80-e__trouble-shooting).

Note. Scan tool is only able to control pressure control solenoid in Park and Neutral with vehicle stopped. This protects clutches from extremely high or low pressures in Reverse and Drive.

LINE PRESSURE SPECIFICATIONS

Scheme 32

TORQUE CONVERTER

Note. For diagnosing torque converter clutch, see AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1995 article or AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1996 article.

TORQUE CONVERTER INSPECTION

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

1. Damage To Oil 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 STALL SPEED TEST

1. Torque converter whine is usually noticed when vehicle is stopped and transmission is in Reverse or Drive. Whine will increase when engine RPM is increased and will stop when vehicle is moving or when torque converter clutch is applied. Stall speed test is to ensure whine is coming from torque converter.
2. Start engine, and allow it to reach normal operating temperature. Apply parking and service brakes. Put transmission in Drive. Depress accelerator to approximately 1200 RPM for less than 6 seconds. DO NOT depress accelerator for more than 6 seconds or transmission damage may occur. Torque converter noise will increase under this load.

Note. Torque converter whine should not be confused with pump whine, which is usually noticeable in Park, Neutral and all other gear ranges. Pump whine will vary with pressure.

TORQUE CONVERTER STATOR CHECK

1. Torque converter stator roller clutch can either remain locked up at all times or freewheel in both directions. If stator is freewheeling at all times, vehicle tends to have poor acceleration from a stop. Vehicle may act normal at speeds above 30-35 MPH.
2. If poor acceleration is noted, ensure exhaust system is not blocked, engine timing is correct and transmission is in 1st gear when starting from a stop. If stator is locked up at all times, performance from a stop appears normal. Engine RPM and acceleration is limited at high speeds. Engine may overheat from this condition.
3. A visual inspection of torque converter may reveal converter is Blue from overheating. If torque converter has been removed from vehicle, stator roller clutch can be checked by inserting a finger into splined inner race of roller clutch and trying to turn race in both directions. Inner race should turn freely clockwise but should not turn or should be difficult to turn counterclockwise.

TORQUE CONVERTER END PLAY CHECK

Mount Torque Converter End Play Fixture (J-39195) and Dial Gauge (J-8001) on torque converter to check end play. Push down on fixture handle to bottom stator. Zero dial gauge. Pull up on fixture handle and check reading. End play should be 0-.024" (0-0.60 mm). (Scheme 33)

Scheme 33

REMOVAL & INSTALLATION

See appropriate AUTOMATIC TRANSMISSION REMOVAL article in the TRANSMISSION SERVICING section.

SPEED SENSORS/REAR HOUSING

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

LOWER TRANSMISSION ASSEMBLY

Remove oil pan and oil filter. Remove accumulator assembly. (Scheme 74) Remove 21 valve body bolts. Remove valve body assembly. (Scheme 76) Remove check balls from case. (Scheme 88) Remove wiring harness. (Scheme 90) Remove parking pawl and manual linkage. (Scheme 34)

Scheme 34

SERVO ASSEMBLIES

Remove servo covers and assemblies. (Scheme 72), (Scheme 73) and (Scheme 87).

Rear Band Apply Pin Selection

1. Install Band Apply Selector Pin (J-21370-10) into servo bore. (Scheme 35) Mount Band Apply Pin Selector Gauge (J-38737) and selector pin on transmission. (Scheme 36) Apply 25 ft. lbs. (34 N.m) of torque to hex nut on gauge.
2. Note which step on selector pin lines up with top edge of apply pin gauge. Use this information to determine pin length. (Scheme 35)and (Scheme 37). Record length for reassembly. Pins are available in various lengths. (Scheme 37)

Scheme 35

Scheme 36

Scheme 37

END PLAY CHECKS

1. Using Dial Indicator (J-8001), check front and rear unit end play. (Scheme 38)and (Scheme 39). Press down on turbine shaft, then pull up on turbine shaft to eliminate any clearance between overdrive carrier and snap ring. Pull up on turbine shaft while holding output carrier up with screwdriver to measure front unit end play. Front unit end play should be.004-.022" (.10-.56 mm).
2. Push in on output shaft to take up any slack. Then move output shaft in and out to measure rear unit end play. Rear unit end play should be.005-.025" (.13-.63 mm). Record measurements for reassembly reference.

Scheme 38

Scheme 39

OIL PUMP & VALVE BODY

Remove oil pump assembly cover bolts. Using Removal Tool (J-37789), remove oil pump assembly. Remove gasket and thrust washer. (Scheme 86) Remove 21 valve body bolts. Remove valve body assembly.

OVERDRIVE ASSEMBLY & 4TH CLUTCH

Remove turbine shaft and overdrive assembly. (Scheme 61) Using 40T Torx wrench, remove 4th clutch support bolt and discard. (Scheme 77) Remove 4th clutch snap ring and assembly. (Scheme 84)

FORWARD & DIRECT CLUTCH

Using Clutch Remover (J-38358-A), remove forward clutch assembly. (Scheme 81) Using Clutch Remover (J-38733), remove direct clutch assembly. (Scheme 80)

INTERMEDIATE CLUTCH

Remove snap ring. Remove intermediate clutch plates and front band. (Scheme 79)

CENTER SUPPORT & REAR GEAR UNIT

1. Remove center support bolt and discard. (Scheme 77) Remove snap ring. Using Gear Assembly Remover/Installer (J-38868), Adapter (J-21364-A) and Slide Hammer Handle (J-6125-B), remove gear assembly. (Scheme 78)
2. Remove rear case snap ring. (Scheme 40) Remove rear band and thrust washer. If necessary, select proper selective thrust washer based on end play measurements. See «END PLAY CHECKS»(/gmc/suburban/i-1992-1999/remont/automatic-trans/#automatic-transmission-overhaul-4l80-e__end-play-checks) under TRANSMISSION DISASSEMBLY. Set thrust washer aside for reassembly.

Scheme 40

Cleaning & Inspection

Thoroughly clean transmission case with solvent and dry using compressed air. Inspect transmission case for damage to band lugs, snap ring grooves, drive sprocket bearings, 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.

Inspection

DO NOT wash bands in solvent. Inspect each band assembly for heat damage, lining cracks and separation. Check band stop for damage and replace if necessary. If rear band is replaced, recheck apply pin. See SERVO ASSEMBLIES under TRANSMISSION DISASSEMBLY .

Disassembly

Remove snap rings. Separate center support, output carrier, reaction carrier and parts of rear gear unit. (Scheme 42)

Using Clutch Compressor (J-23327) and Adapter (J-38734), compress intermediate clutch springs, and remove snap ring. Separate center support from intermediate clutch assembly. (Scheme 44)

1. Inspect output carrier, reaction carrier and reaction drum for damaged teeth, scoring or warpage. Check thrust bearing for damage. Using a feeler gauge, check output carrier and reaction carrier pinion gear end play. (Scheme 41)and (Scheme 43).
2. End play should be.009-.024" (.23-.61 mm). Check for damage to reaction carrier internal gear. Ensure center support cup plug bleed hole opening is about.020" (.51 mm). (Scheme 45)

Reassembly

Using Piston Installer (J-21362), install intermediate piston to center support. (Scheme 46) Reassemble center support and rear gear unit. (Scheme 47)-24. Install NEW oil seal rings to center support. Preheat oil seal rings in hot water prior to installation.

Scheme 41

Scheme 42

Scheme 43

Scheme 44

Scheme 45

Scheme 46

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Disassemble intermediate sprag clutch assembly. Discard spiral snap ring. Remove direct clutch plates (Scheme 51) Using Clutch Compressor (J-23327) and Adapter (J-25018-A), compress direct clutch springs, and remove snap ring.

Scheme 51

Inspect all parts for wear, cracks, burned plates and scoring; replace if necessary.

1. Reassemble intermediate sprag clutch. Install intermediate clutch race with grooves facing up. (Scheme 52) Install NEW spiral snap ring. Ensure intermediate sprag rotates clockwise only. (Scheme 53)
2. Using Clutch Piston Installers (J-21362 and J-38732), install piston into direct clutch housing. Reassemble direct clutch. Direct clutch uses 5 steel plates, 5 composition plates and one dished plate. (Scheme 51)and (Scheme 54).
3. Apply 80 psi (550 kPa) of air to reverse port. (Scheme 55) Air should bleed through direct port. Apply air pressure to direct port. Ensure piston seals do not leak. Direct clutch piston should move.121-.186" (3.07-4.72 mm).

Scheme 52

Scheme 53

Scheme 54

Scheme 55

FORWARD CLUTCH

Note. Prior to checking forward clutch piston movement, check identification plate attached to rear of transmission case. Units with ZFP identification are set to a different specification.

Disassemble forward clutch assembly. (Scheme 56) Using Clutch Spring Compressor (J-23327-1), compress and remove spring and retainer assembly. (Scheme 58) Remove clutch piston and seals from piston.

Inspect all clutch plates for cracks, wear, lining separation, pits or other signs of damage. Ensure forward clutch housing check ball is working. Inspect thrust washer for damage. Inspect clutch housing for damaged clutch hub, worn bushings or damaged oil seal rings.

1. Using Clutch Piston Installers (J-21362 and J-38732), install piston into forward clutch housing. Reassemble forward clutch. (Scheme 56) Install correct number of clutch plates. See «FORWARD CLUTCH PLATE APPLICATION»(/gmc/suburban/i-1992-1999/remont/automatic-trans/#automatic-transmission-overhaul-4l80-e) table.
2. Apply 80 psi (550 kPa) of air to turbine shaft air port. (Scheme 57) Ensure piston seals do not leak. Check forward clutch piston movement. Forward clutch piston should move.121-.186" (3.07-4.72 mm) on all except model ZFP. On model ZFP, forward clutch piston should move.087-.150" (2.21-3.81 mm).

FORWARD CLUTCH PLATE APPLICATION

Scheme 56

Scheme 57

Scheme 58

Remove snap ring and backing plate. (Scheme 59) Remove clutch plates. Using Clutch Spring Compressors (J-23327-1 and J-38882), compress and remove spring retainer. Remove clutch piston and seals from piston.

Inspect housing and clutch plates for damaged teeth, scoring or warpage. Ensure 4th clutch housing cup plug bleed hole opening is about .020" (.51 mm).

1. Using Piston Seal Protectors (J-38731-1, J-38731-2 and J-38731-3), install piston into 4th clutch housing. Reassemble 4th clutch assembly. (Scheme 59)
2. Install snap ring. Install 4 steel and 4 composition plates. Ensure steel plate notches are indexed opposite 4th clutch bolt hole. Ensure clearance between backing plate and snap ring is.040-.100" (1.01-2.54 mm). (Scheme 60)

Scheme 59

Scheme 60

Remove overrun clutch housing from overdrive assembly. (Scheme 61) Disassemble overrun clutch. (Scheme 62)and (Scheme 69). Using Clutch Spring Compressor (J-23327) and Adapter (J-38734), compress spring retainer, and remove clutch piston. (Scheme 62) Disassemble overdrive assembly. (Scheme 69) If necessary, disassemble overdrive carrier assembly. (Scheme 67)

Inspect housing and clutch plates for damaged teeth, scoring or warpage. Inspect spring and spring retainer for damage. Inspect overdrive carrier assembly and turbine shaft for wear or damage. Replace if necessary. Ensure overdrive carrier pinion end play is.009-.024" (.23-.61 mm). (Scheme 64)

Turbine Shaft Seal Replacement

1. Remove oil seal rings from turbine shaft. Inspect seal ring grooves for nicks or burrs. Lubricate each oil seal ring. Place Seal Protector/Installer Kit (J-38736) on turbine shaft.
2. Quickly slide each seal into ring groove when protector is in position. Use seal driver from Kit (J-38736) to push ring over seal protector. Size seal with seal sizer from Kit (J-38736); gently twist seal sizer over each seal. Leave sizer in place.

Scheme 61

Scheme 62

1. Using Piston Seal Protector (J-38729), install piston into overrun clutch housing. (Scheme 63) Reassemble overrun clutch assembly. (Scheme 62)
2. Install snap ring. Install 3 steel and 3 composition plates. Ensure clearance between backing plate and snap ring is.033-.094" (.838-2.39 mm). (Scheme 65)
3. If necessary, reassemble overdrive carrier. (Scheme 66), (Scheme 67) and (Scheme 69). Install thrust washer to overdrive carrier. (Scheme 66) To complete reassembly, install turbine shaft and overdrive carrier to overrun clutch. (Scheme 61)and (Scheme 69).

Scheme 63

Scheme 64

Scheme 65

Scheme 66

Scheme 67

Clean and air dry oil pump. Disassemble oil pump. (Scheme 68)for exploded view of pump assembly. Use caution when removing reverse boost valve snap ring. Regulator spring is under extreme pressure.

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

1. Reassemble oil pump. (Scheme 68) Install oil pump gears into pump body with identification dots facing up. Measure gear clearance between oil pump gears and pump body. Clearance should be.0007-.0028" (.017-.071 mm).
2. Ensure pump body mating surface is flat. Install pump cover onto body. Install cover bolts and hand tighten bolts. Install Alignment Pin (J-25025-1) into pump. Install and tighten oil pump Alignment Band (J-21368). (Scheme 71) Tighten oil pump attaching bolts.
3. To install TCC enable valve, compress spring into oil pump body, and insert a small rod into hole "A". (Scheme 70) Install spring retainer, and remove small rod.

Scheme 68

Scheme 69

Scheme 70

Scheme 71

Inspection & Reassembly

Inspect servo pistons and seals for damage or cracks. DO NOT remove seals unless replacement is required. Inspect springs for damaged coils. Replace all damaged parts, and reassemble servos. (Scheme 72), (Scheme 73) and (Scheme 87).

Scheme 72

Scheme 73

Inspect accumulator pistons and seals for damage or cracks. DO NOT remove seals unless replacement is required. Inspect springs for damaged coils. Replace all damaged parts, and reassemble accumulators. (Scheme 74)

Scheme 74

Thoroughly clean valve body and dry with compressed air. Cover bores when removing roll pins because some valves are under pressure. Remove valves, springs and bushings, and place on a clean surface in order removed. Remove control solenoids. Remove blind hole roll pins with a drill bit. 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.

To reassemble valve body assembly, reverse disassembly procedure. (Scheme 76)

TRANSMISSION REASSEMBLY

Note. All selective thrust washer measurements taken during disassembly must be rechecked at appropriate reassembly stage. (Scheme 91)for exploded view of internal transmission components. (Scheme 92)for lip seal location and installation direction.

1. Install rear band and thrust washer. Ensure band anchor pins engage band, and band assembly stop is in place. Install proper selective thrust washer. (Scheme 75) Install rear case snap ring. Install snap ring groove into case, with snap ring opening at 9 o'clock position. (Scheme 40)
2. Using Gear Assembly Remover/Installer (J-38868), Adapter (J-21364-A) and Slide Hammer Handle (J-6125-B), install gear assembly. (Scheme 78)
3. Install upper center support snap ring with flat side down and opening at 9 o'clock position. Using Dial Indicator (J-8001), check rear unit end play. (Scheme 39) Rear unit end play should be.005-.025" (.13-.63 mm).
4. If rear unit end play is not correct, select proper size thrust washer. See «REAR END PLAY THRUST WASHER»(/gmc/suburban/i-1992-1999/remont/automatic-trans/#automatic-transmission-overhaul-4l80-e) table. If necessary, remove center support and rear unit to change selective thrust washer.
5. Using Center Support Aligner (J-23093), push center support splines counterclockwise against case splines (away from rear servo). Align center support with bolt hole. Using NEW bolt, install center support bolt. (Scheme 77) Tighten bolt to 32 ft. lbs. (43 N.m).

REAR END PLAY THRUST WASHER

Scheme 75

Scheme 76

Scheme 77

Scheme 78

Install intermediate clutch plates (4 steel and 4 composition). (Scheme 79) Install backing plate with flat side down. Install snap ring at 9 o'clock position. Ensure clearance between clutch plates and backing plate is.040-.107" (1.02-2.72 mm). Using Clutch Plate Aligner (J-24396), align intermediate clutch assembly.

Scheme 79

Apply air pressure into center support hole to hold intermediate clutch plates in place. Using Clutch Installer (J-38733), install direct clutch assembly and front band. (Scheme 79)and (Scheme 80). Using Clutch Installer (J-38358-A), install forward clutch assembly and thrust bearing. (Scheme 81)and (Scheme 91).

Note. Check installed height of speed sensor ring (on forward clutch housing). Top of speed sensor ring to oil pump gasket surface height should be 3.85-3.89" (98.0-99.0 mm).

Scheme 80

Scheme 81

1. Install 4th clutch support (without clutch plates) into transmission case. Using 40T Torx wrench, install NEW 4th clutch support bolt. (Scheme 82) Tighten bolt to 17 ft. lbs. (23 N.m).
2. Remove turbine seal sizer from turbine shaft. Install turbine shaft and overdrive assembly. (Scheme 61) Ensure assembly is fully seated. Install 4th clutch plates (4 steel and 4 composition). Install steel plates with narrow tang "V" notch at 1 o'clock position in housing. (Scheme 83) Install backing plate and snap ring. (Scheme 84)

Scheme 82

Scheme 83

Scheme 84

OIL PUMP

1. Install Locating Pin (J-25025-1) at 12 o'clock position. Install oil pump cover gasket. (Scheme 85) Install selective thrust washer. Using Handle (J-37789), install oil pump assembly. (Scheme 86) Ensure turbine shaft spins free. Tighten oil pump mounting bolts.
2. Using Dial Indicator (J-8001), check front unit end play. (Scheme 38) Front unit end play should be.004-.022" (.10-.56 mm). If front unit end play is not correct, select proper size thrust washer. See «FRONT END PLAY THRUST WASHER IDENTIFICATION»(/gmc/suburban/i-1992-1999/remont/automatic-trans/#automatic-transmission-overhaul-4l80-e) table. If necessary, remove oil pump assembly to change selective thrust washer.

Scheme 85

Scheme 86

FRONT END PLAY THRUST WASHER IDENTIFICATION

Install selected rear band apply pin. If necessary, check rear band apply pin using Band Apply Selector Pin (J-21370-10) and Band Apply Pin Gauge (J-38737). See SERVO ASSEMBLIES under TRANSMISSION DISASSEMBLY. Install front and rear servo assemblies. (Scheme 72), (Scheme 73) and (Scheme 87).

Scheme 87

Install parking pawl and manual linkage. (Scheme 34) Install check balls in case. Check ball No. 2 is only used in models RKL, RLP and ZJP. (Scheme 88) Assemble and install accumulator assembly. (Scheme 74) Tighten accumulator assembly bolts in sequence. (Scheme 89) Install valve body assembly. Install lube pipe and wiring harness. (Scheme 90) Install oil pan and oil filter.

SPEED SENSORS & REAR HOUSING

Install and secure torque converter. Install rear extension housing. Install speed sensors.

Scheme 88

Scheme 89

Scheme 90

Scheme 91

Scheme 92

TRANSMISSION SPECIFICATIONS

TRANSMISSION SPECIFICATIONS

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

WIRING DIAGRAMS

Note. See AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1995 article or AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1996 article.

See also:
• OIL PUMP & VALVE BODY
• CLUTCH & BAND APPLICATION CHART (4L80-E)
• ROAD TEST
• HYDRAULIC PRESSURE TESTS
• SYMPTOM DIAGNOSIS
• TROUBLE SHOOTING
• END PLAY CHECKS