Automatic Transmission Overhaul - 4L60-E: Other GMC Envoy I

VALVE BODY

1st Gear Only, No Upshift

Check 1-2 shift valve sticking in valve body. Spacer plate or gaskets damaged or not positioned properly. Case-to-valve body face damaged or not flat. 2-4 servo assembly restricted or blocked case passages. Nicks or burrs on servo pin or case pin bore. Missing or damaged piston or pin seals. 4th servo piston installed backward. 2-4 band worn or damaged, or band anchor pin not engaged. Check shift solenoids.

Slips In 1st Gear

Defective forward clutch assembly. Clutch plates worn. Piston porous or damaged. Piston seals missing or damaged. Input housing-to-forward clutch housing "O" ring seal missing or damaged. Damaged housing. Housing retainer and ball assembly damaged or not seating. Input shaft and housing assembly turbine shaft seals missing or damaged. Accumulator valve stuck in valve body.

Valve body face not flat, damaged lands, or interconnected passages. Spacer plate or gaskets incorrect, damaged or not positioned properly. Check for defective 1-2 accumulator piston assembly. Porosity in piston or cover and pin assembly. Damaged piston ring grooves. Piston seal missing or damaged. Cover gasket missing or damaged. Broken accumulator spring.

Incorrect oil pressure. Torque converter stator roller clutch not holding or 4th servo piston in backward. Damage to low roller clutch lugs or inner ramps. Rollers not free moving, inadequate spring tension or damage to inner splines. Oil passage plugged. Forward clutch accumulator piston seal missing or damaged. Piston out of its bore. Stuck abuse valve.

Slipping Or Rough 1-2 Shift

Check for defective valve body assembly. 1-2 shift valve train or accumulator valve stuck. Gaskets or spacer plate incorrect, damaged or not installed properly. Valve body face not flat.

Defective 2-4 servo assembly. Apply pin length incorrect. Servo seals or "O" ring seals missing or damaged. Restricted or missing oil passages. Case servo bore damaged. Defective 2nd accumulator. Porosity in 1-2 accumulator housing or piston. Piston seal or groove damaged. Nicks or burrs in 1-2 accumulator housing. Missing or restricted oil passages or 2-4 band worn or not positioned properly. Oil pump assembly or case faces not flat.

Slipping, Rough Or No 2-3 Shift

Check for defective valve body assembly. 2-3 shift valve train or accumulator valve stuck. Gaskets or spacer plate incorrect, damaged or not installed properly. Valve body face not flat.

Defective 2-4 servo assembly. Apply pin length incorrect. Servo seals or "O" ring seals missing or damaged. Restricted or missing oil passages. Case servo bore damaged. Defective 2nd accumulator. Porosity in 1-2 accumulator housing or piston. Piston seal or groove damaged. Nicks or burrs in 1-2 accumulator housing. Missing or restricted oil passages or 2-4 band worn or not positioned properly. Oil pump assembly or case faces not flat.

1st & 4th Or 2nd & 3rd Gear Only

Check shift solenoids for dirt, damaged seals or electrical connections.

3rd Gear Only

Check 2-3 shift solenoid and 3-2 control solenoid circuits, damaged seals or electrical connections.

3-2 Flare Or Tie Up

Check 3-2 control solenoid for dirt, damaged seals or electrical connections.

Slipping, Rough Or No 3-4 Shift

Check oil pump assembly faces not flat or pump cover retainer and ball assembly omitted or damaged. Valve body assembly 2-3 shift train, accumulator valve, 1-2 shift valve or 3-2 control valve stuck. Manual valve link bent or damaged. Spacer plate or gaskets incorrect, damaged or not positioned properly. Defective 2-4 servo assembly.

Incorrect band apply pin. Servo seals missing or damaged. Porosity in pistons, cover or case. Plugged or missing orifice cup plug. Case 3rd accumulator retainer and ball assembly leaking. Porosity in 3-4 accumulator piston or bore. 3-4 accumulator piston seal or seal grooves damaged. Restricted oil passage. Defective input housing assembly. Forward or 3-4 clutch plates worn, or excessive plate travel.

Forward or 3-4 piston seals damaged. Porosity in 3-4 clutch housing or piston. 3-4 piston check ball stuck, damaged or not sealing. Restricted apply passages. Forward clutch piston retainer and ball assembly not seating. 2-4 band worn or not positioned properly. Sealing balls loose or missing.

No Reverse Or Slips In Reverse

Defective input housing assembly. 3-4 apply ring stuck in applied position. Forward clutch not releasing. Turbine shaft seals missing or damaged. Manual valve link disconnected.

Defective valve body assembly. 2-3 shift valve stuck. Manual linkage out of adjustment. Spacer plate and gaskets incorrect, damaged or not positioned properly. Defective reverse input clutch assembly. Clutch plate worn. Housing and drum assembly cracked at weld. Clutch plate or return spring assembly retaining ring out of groove. Piston deformed or dished.

Seals damaged or missing. Retainer and ball assembly not sealing. Restricted apply passage. Defective low-reverse clutch. Clutch plates worn or retaining ring not positioned properly. Porosity in piston. Seals damaged. Return spring assembly retaining ring not positioned properly. Case porosity. Case cover plate not tightened properly or gasket missing or damaged.

No Part-Throttle Or Delayed Downshifts

Check for defective 2-4 servo assembly. Servo cover retaining ring missing or not assembled properly. 4th apply piston damaged or not assembled properly. Inner housing damaged or not assembled properly. Defective valve body assembly. 3-2 control valve stuck. 4-3 sequence valve body channel blocked. No. 5 check ball missing.

Harsh Garage Shifts

Check valve body for missing check ball, or orifice cup plug.

No Overrun Braking In Manual 3-2-1

Defective valve body assembly. 4-3 sequence valve or throttle valve stuck. No. 3 check ball not positioned properly. Spacer plate and gaskets incorrect, damaged or not positioned properly. Defective input clutch assembly. Turbine shaft oil passages plugged or not drilled. Turbine shaft seal rings damaged. Turbine shaft sealing balls loose or missing. Porosity in forward or overrun clutch piston. Overrun piston seals damaged or cut. Overrun piston check ball not sealing.

Drives (Creeps) In Neutral

Forward clutch not releasing. Manual valve link disconnected. Converter clutch apply valve stuck in oil pump. Face of transmission case not flat or internal leakage in case.

Starts In 2nd In "D"

Forward sprag clutch assembly installed backward.

No Park

Parking linkage binding, loose, missing or not positioned properly.

Oil Pressure High Or Low

Oil pressure regulator valve stuck or valve spring damaged. Rotor guide omitted or not assembled properly. Rotor cracked or reverse boost valve or sleeve stuck, damaged or not assembled properly. Orifice hole in pressure regulator valve plugged. Sticking slide or excessive rotor clearance. Pressure relief ball not seated or damaged. Pump cover or body has porosity. Incorrect pump cover or pump face not flat. Excessive rotor clearance.

Intake pipe restricted by casting flash. Cracks in filter body or intake pipe. "O" ring seal missing, cut or damaged. Incorrect lubricant used during rebuild procedure.

Manual valve scored or damaged. Spacer plate or gaskets incorrect, damaged or not assembled properly. Check for stuck 2-3 shift valve, damaged pressure control solenoid or damaged pressure switch assembly. Check for missing check balls or incorrect assembly. Case-to-valve body face not flat.

Harsh Shifts

Check PCM input signals from TP sensor, pressure switch assembly, fluid temperature sensor, VSS and engine coolant temperature sensor. Inspect pressure control solenoid for damaged pins or seals, or dirt in oil circuits.

High Or Low Shift Points

Check for stuck pressure regulator valve or pump slide sticking. Spacer plate or gaskets damaged, incorrect or not assembled properly.

Valve body pad porous or damaged. 2-4 accumulator has porosity. Servo piston seals damaged. Apply pin damaged or has improper length. 2-4 band burned or anchor pin not engaged. Throttle Position (TP) sensor, VSS and/or 4WD low switch (if equipped) disconnected or damaged.

No Converter Clutch Apply

Transmission not supplied 12 volts. Outside electrical connector damaged. Inside electrical connector wiring harness or solenoid damaged. Solenoid wire pinched. Solenoid not grounded. Pressure switches incorrect or damaged. Temperature sensor damaged. Damaged engine speed sensor or pressure switch assembly. Converter internal damage.

Converter clutch valve stuck or assembled backward, or retaining ring not positioned properly. Pump-to-case gasket not positioned properly. Orifice cup plug restricted or damaged. Solenoid "O" ring seal cut or damaged. Pump-to-body cover high or uneven bolt torque.Turbine shaft "O" ring seal cut or damaged. Turbine shaft retainer and ball assembly restricted or damaged. TCC shift valve or apply valve stuck. Solenoid "O" ring leaking. Solenoid screen is blocked.

Converter Shudder

Torque converter has internal damage. Converter clutch valve stuck. Restricted oil passages. Crack in filter body. Restriction in filter neck. "O" ring seal cut or damaged. Turbine shaft "O" ring cut or damaged. Turbine shaft retainer and ball assembly restricted or damaged. Low oil pressure. Engine not tuned properly.

No Converter Clutch Release

Solenoid external ground. Converter internal damage. Converter clutch valve stuck. Converter clutch apply valve stuck in apply position. PCM external ground faulty.

Converter Clutch Applies When Cold

Check engine coolant temperature sensor and trouble codes.

Oil Leaking Out Vent

Chamber in pump body rotor pocket too large. Fluid level overfilled. Cross leak out of pump body and cover.

Front Oil Leak

Torque converter welded seam leaking. Damaged torque converter hub. Damaged front seal.

Pump Bushing Spins Out, "Walks" Into Seal, Or Seizes To Converter Hub

Transmission and engine center lines do not match. Excessive crankshaft runout. Bent flexplate (drive plate). Excessive converter hub runout. Pump bushing I.D. not centered in pump. Bushing too loose in pump. Not enough hub-to-bushing clearance.

Falls Out Of 4th Gear During Coasting

Low line pressure at idle (weak pressure regulator spring).

Binds Up On 3-4 Shift (Feels Like Brake Drag)

Forward pressure plate installed incorrectly. Too many plates in overrun clutch. Incorrect top steel plate installed in overrun clutch.

No Forward Or Reverse Gears (Line Pressure Reading Okay)

Mismatched converter input shaft or broken turbine hub.

Binds Up In Reverse

Stator sleeve rotated out of position. Stuck2-3 shift valve. Servo pin jammed in case. Stuck 3-4 relay or 4-3 sequence valve.

No Drive In "D" Range

Torque converter stator roller clutch not holding.

No Drive In "OD" Range

Faulty output sprag. Teeth "hammered" out of forward friction plates.

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.

Gear Selector Position "D4" (Overdrive)

1. With gear selector in "D4" (overdrive) position, choose throttle position angle of 12 or 25 percent. (Scheme 24)or (Scheme 25). Set scan tool to monitor throttle position angle and vehicle speed. Accelerate vehicle to chosen throttle position angle and hold throttle steady.
2. Note shift speed engagement points in 2nd gear, 3rd gear and overdrive gear. Use charts as a reference for proper shift speeds. (Scheme 24)or (Scheme 25). Also note Torque Converter Clutch (TCC) engagement point while in overdrive. Repeat procedure using different throttle position angle. NOTE: Shift speeds may vary due to slight hydraulic delays responding to electronic controls. A change from original equipment tire size also affects shift speeds. Ensure TCC engages in 3rd or overdrive. TCC should not apply unless transmission has reached a minimum operating temperature of 64°F (18°C) and engine coolant temperature is 140°F (60°C).
3. At vehicle speeds of 40-50 MPH in overdrive, quickly increase throttle position angle to more than 50 percent. Verify TCC releases, transmission immediately downshifts to 3rd gear and 1-2 shift solenoid turns off.
4. At vehicle speeds of 40-50 MPH in overdrive, quickly depress accelerator to wide open position (full throttle detent downshift). Verify TCC releases, transmission immediately downshifts to 2nd gear, 1-2 solenoid is off and 2-3 solenoid is on.
5. At vehicle speeds of 40-55 MPH in overdrive, release accelerator pedal while moving gear selector to "D3" (third gear) position. Verify TCC releases, transmission immediately downshifts into 3rd gear, and engine braking slows vehicle.
6. Move gear selector to "D4" (overdrive) position, and accelerate to 40-45 MPH. Release accelerator pedal while moving gear selector to "D2" (2nd gear) position. Verify TCC releases, transmission immediately downshifts to 2nd gear, and engine braking slows vehicle.
7. Move gear selector to "D4" (overdrive) position, and accelerate to 30 MPH. Release accelerator pedal while moving gear selector to "D1" (1st gear) position. Verify TCC releases, transmission immediately downshifts to 1st gear and engine braking slows vehicle.
8. With gear selector in the "D4" (overdrive) position, accelerate vehicle to overdrive gear with TCC applied. Release accelerator pedal, and lightly apply brakes. Verify TCC releases and downshifts occur at speeds shown in shift speed charts. (Scheme 24)or (Scheme 25).

Note. Upshifts in manual gear ranges are controlled by shift solenoids. Perform following steps by accelerating vehicle at throttle position angle of 10-15 percent.

Gear Selector Position "D3" (3rd Gear)

With vehicle stopped, move gear selector to "D3" (3rd gear) position and steadily increase throttle pressure to accelerate vehicle. Note speeds at which vehicle shifts into 2nd and 3rd gears. (Scheme 24)or (Scheme 25).

Gear Selector Position "D2" (2nd Gear)

With vehicle stopped, move gear selector to "D2" (2nd gear) position. Accelerate vehicle and note speed at which vehicle shifts from 1st gear to 2nd gear. Accelerate vehicle to 35 MPH. Verify transmission does not shift into 3rd gear, and TCC does not apply.

Gear Selector Position "D1" (1st Gear)

With vehicle stopped, move gear selector to "D1" (1st gear) position. Accelerate vehicle to 20 MPH. Verify transmission does not upshift, and TCC does not apply.

Gear Selector Position "R" (Reverse)

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

Scheme 24

Scheme 25

CHECKING SERVO PIN LENGTH

1. Remove 4th apply piston and return spring. (Scheme 26) Remove retainer ring, washer, apply pin spring and 2nd apply pin. Install Piston Compressor (J-22269-01) on 2nd apply piston. (Scheme 27)
2. Remove retainer ring, cushion spring and spring retainer. Install Band Apply Pin Tool (J-33037) and apply pin. (Scheme 28) Apply 100 INCH lbs. (11 N.m) torque.
3. White line on band apply tool should be within gauge slot if pin length is correct. If White line is not within gauge slot, inspect 2-4 band and reverse input drum for wear and damage during disassembly.
4. Servo pin length must be checked during reassembly. Servo pin is preset and must not be readjusted. See «SERVO PIN SPECIFICATIONS»(ref-124191-S24469262722001100100000) table under 2-4 BAND & SERVO ASSEMBLY under TRANSMISSION REASSEMBLY.

Scheme 26

Scheme 27

Scheme 28

EXTENSION HOUSING

Remove speed sensor retaining bolt. Using Puller (J-38417), remove speed sensor assembly and "O" ring. (Scheme 31) Remove extension housing and seal. Remove output shaft sleeve and "O" ring (if equipped). Remove speed sensor rotor from output shaft (if necessary). Install Gear Puller (J-21427-01) and Adapter (J-8433) on rotor. Pull rotor from output shaft.

1-2 ACCUMULATOR & SPACER PLATES

1. Remove solenoid retaining bolts. Remove solenoid and "O" ring. Remove wiring harness, and note location for reassembly reference. Carefully remove accumulator cover retaining bolts, 1-2 accumulator cover and pin assembly. (Scheme 31)
2. Remove 1-2 accumulator piston, seal and spring. Remove spacer plate, and note check ball and filter locations. Remove spring, 3-4 accumulator piston and pin. Note spacer plate and gasket locations. see scheme 5for check ball and filter locations.

TRANSMISSION END PLAY CHECK

Note. Check transmission end play before disassembly. If end play is not within specification, check for damaged parts during disassembly.

Install Pump Remover/End Play Fixture (J-24773-A) and End Play Adapter (J-25022-A) on end of turbine shaft. (Scheme 29) Clamp dial indicator on long bolt with indicator tip on end play fixture. Zero dial indicator. Pull up on end play fixture. Measure transmission end play. Transmission end play should be.005-.036" (.13-.91 mm).

Scheme 29

OIL PUMP, INPUT CLUTCH & REVERSE CLUTCH

1. Ensure TCC solenoid assembly and oil filter are removed before oil pump removal. Remove oil pump retaining bolts. Using Oil Pump Remover (J-37789-A) and Adapter (J-39119), pull oil pump assembly free from case. (Scheme 30)
2. Remove oil pump, seal and gasket. Remove reverse input clutch-to-pump thrust washer from pump. Lift out turbine shaft with reverse input clutch assembly.

Scheme 30

2-4 BAND & INPUT GEAR SET

1. Remove band anchor pin from case. (Scheme 31) Remove 2-4 band assembly from case. Remove input sun gear. (Scheme 32) CAUTION: Output shaft must be held in place when removing input carrier retainer ring.
2. Install Output Shaft Support (J-29837) on output shaft. (Scheme 33) Remove input carrier to output shaft retainer ring. Remove input carrier. Remove output shaft. Remove input carrier thrust bearing from reaction carrier shaft.

Scheme 31

Scheme 32

Scheme 33

REACTION GEAR SET

1. Remove input internal gear and reaction carrier shaft. Remove reaction sun shell and thrust washer. Remove sun shell-to-clutch race thrust washer. Remove support-to-case snap ring.
2. Remove support retainer spring from low-reverse support. Remove reaction sun gear, low-reverse roller clutch race, roller clutch, support assembly and reaction carrier assembly. (Scheme 32)
3. Remove low-reverse clutch plates. Note locations of components. Remove internal reaction gear and thrust bearing. Remove internal reaction gear support-to-case thrust bearing.

LOW-REVERSE CLUTCH

Note. Parking pawl may require removal to access low-reverse clutch.

1. Remove parking lock bracket retaining bolts. Remove lock bracket. Using screw extractor, remove shaft plug. Remove parking pawl shaft, parking pawl and return spring if necessary. (Scheme 31)
2. Using Clutch Spring Compressor (J-23327), compress low reverse clutch spring retainer. Remove spring retaining ring and low-reverse spring assembly. Remove low-reverse clutch piston by applying air pressure in case apply passage. (Scheme 34)

Scheme 34

INNER MANUAL SHAFT LINKAGE

Remove manual shaft nut. Remove manual shaft and retainer. Remove parking lock actuator assembly and inner detent lever. Remove manual shaft seal from transmission case. (Scheme 31)

3RD ACCUMULATOR CHECK VALVE

1. Check 3rd accumulator check valve before removing it. DO NOT remove check valve unless it is leaking. Install servo assembly in bore. Install servo cover and retaining ring. see scheme 6 Pour clean solvent in bore. Inspect for leaks in transmission case. Replace check valve assembly if it leaks. (Scheme 35) Remove servo assembly.
2. For check valve removal, install No. 4 screw extractor in check valve assembly. Remove check valve. Ensure bore is free of burrs. Installation tool must be made to ensure proper installation depth is obtained. Using a 3/8" O.D. rod, scribe indicator mark at 1.653" (41.98 mm) from end of rod. Install check valve until scribe mark on rod is flush with case. (Scheme 35)

Scheme 35

Note. Valves are held in valve body by pins or retainers. Valves may be under spring pressure. Note location of all parts during disassembly for reassembly reference.

1. Place transmission in a vertical position. Install seals on low-reverse clutch piston. Apply petroleum jelly to seals. Align and install piston with notch in bottom of transmission case. Ensure piston is fully seated and parking pawl aligns with opening in piston wall. Install spring assembly with flat side of retainer upward. Compress springs and install retainer ring.
2. Coat bearing assembly with petroleum jelly. Install bearing assembly on case hub with outside bearing race toward case hub. Install internal reaction gear and support. Install bearing assembly onto support with outside bearing race toward support. Install oil deflector (if equipped) and reaction carrier assembly in case. (Scheme 32) Ensure clutch plates are proper thickness.
3. Install clutch plates. See «LOW-REVERSE CLUTCH PLATE USAGE»(ref-124191-S20450648312001100100000) table. Ensure clutch plates align with splines of reaction carrier and case and that steel plates are aligned. Place waved plate on work bench. Install 5 composition plates and 4 steel plates alternately, starting with composition plate.
4. Install low-reverse support. Apply light pressure to low-reverse support. DO NOT flatten waved plate. Measure height of clutch pack from work bench to top of low-reverse support. Using height dimension, determine proper selective spacer plate to be used. See SPACER PLATE SELECTION table.
5. Place spacer plate between waved plate and first composition plate with identification facing upward. Measure overall height of clutch pack. Overall height should be 1.15-1.18" (29.2-29.9 mm). Install clutch pack assembly in transmission case.
6. Install low-reverse support in case with hub downward. Install inner race by pushing downward while rotating until it is fully engaged. Bottom tangs will be flush with hub when fully installed. Install spring retainer in case between case lug and open notch in support. Install low-reverse snap ring.

LOW-REVERSE CLUTCH PLATE USAGE

SPACER PLATE SELECTION (1)

REACTION & INPUT GEAR SETS

1. Install retainer ring on reaction sun gear (if removed). Install sun gear into reaction carrier. Install thrust washer on low-reverse clutch race. Install reaction sun gear shell on reaction sun gear.
2. Install thrust washer on reaction sun gear shell. Ensure thrust washer tangs engage on gear shell. Install input internal gear and reaction carrier shaft in sun gear shell. Carrier shaft splines must engage with reaction carrier. (Scheme 32)
3. Install thrust washer on reaction carrier shaft. Outer race must face toward reaction carrier shaft. Install output shaft in transmission. Ensure output shaft engages with all parts.
4. Install Output Shaft Support (J-29837). Adjust support so output shaft is positioned upward as far as possible. Install input carrier assembly with hub end down on output shaft. Install NEW retainer ring on output shaft. Remove output shaft support. Install input sun gear, indexing gear end with input carrier pinions.

REVERSE & INPUT CLUTCHES

Install reverse and input clutch assemblies in transmission case as an assembly. Align 3-4 clutch plates of input assembly with input internal gear. Assembly is fully seated when reverse input clutch housing is just below oil pump face of case.

BUSHINGS, SEALS, BEARINGS & THRUST WASHERS

Note. To identify bushing, seal, thrust bearing and thrust washer locations and direction (Scheme 37)and (Scheme 38).

Scheme 36

Scheme 37

Scheme 38

Scheme 39

1. Turbine shaft seals should be installed prior to oil pump installation. Position Seal Installer (J-36418-1) on input shaft. (Scheme 39) Adjustment screw in seal installer must be adjusted to obtain correct height for each seal installation. Install 4 turbine shaft seals.
2. Turbine shaft seals must be sized using Seal Sizer (J-36418-2A) after installation. Install aligning pins in 2 opposing pump bolt holes in case. Ensure thrust washer is installed on rear of oil pump. Thrust washer can be retained using petroleum jelly.
3. Install oil pump into case, aligning filter and pressure regulator holes with holes in case. Install retaining bolts. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-124191-S11448589012001100100000). Place transmission in a horizontal position.
4. Turbine shaft should rotate by hand. If turbine shaft will not rotate, loosen pump retaining bolts and attempt to rotate shaft again. If shaft now turns, reverse and input assemblies have not been indexed properly or some other assembly problem has occurred, such as thrust washer not positioned properly.
5. Check transmission end play. See «TRANSMISSION END PLAY CHECK»(ref-124191-S02016652352001100100000) under TRANSMISSION DISASSEMBLY. Transmission end play should be.005-.036" (.13-.91 mm). If transmission end play is not within specification, thrust washer must be changed between oil pump and input housing.
6. See «OIL PUMP THRUST WASHER SPECIFICATIONS»(ref-124191-S27878434142001100100000) table. Install thrust washer, and recheck end play. Install torque converter. Ensure converter hub is aligned with oil pump. Install torque converter retaining strap to hold converter.

OIL PUMP THRUST WASHER SPECIFICATIONS

1. Install 3-4 accumulator piston pin in case. Install 3-4 piston seal on piston. Install 3-4 accumulator piston on pin. Legs of piston must face valve body.
2. Install 3-4 accumulator spring. Install oil screens in proper locations. (Scheme 36) Install special retainer and ball assembly. see scheme 5for check ball and filter installation locations. Install spacer plate gasket and spacer plate.
3. Install 1-2 accumulator spring, oil seal ring and 1-2 accumulator piston. Install accumulator cover and bolts. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-124191-S11448589012001100100000).

Install valve body. See VALVE BODY under ON-VEHICLE SERVICE .

1. Install speed sensor rotor retaining clip on output shaft. Install "O" ring in output shaft sleeve. Install output shaft sleeve on output shaft. DO NOT position output sleeve past machined surface of output shaft. Install seal ring on extension housing.
2. Position extension housing on transmission case. Install retaining bolts. Install oil seal in extension housing. Install speed sensor assembly. Install retainer and bolt. Tighten bolt to specification. Install outside electrical connector and manual shift lever.

1-2 &/OR 2-3 UPSHIFT SLIP/FLARE, NO 3RD OR 4TH GEAR

(DTC P1870)

Some owner's may complain that vehicle has either a slip or flare on 1-2 and/or 2-3 upshift, or no 3rd or 4th gear. DTC P1870 may also be present. This condition may be caused by a poor internal ground between 2 circuit boards of Vehicle Control Module (VCM), which can cause VCM to command erratic line pressure at pressure control solenoid. To correct this condition, a revised Wiring Harness (12167310) has been designed to replace current wiring harness at VCM. Corrections were made to VCM beginning February 14, 1996. Corrected VCM's are identified by service number 16244210, located on VCM identification label.

All GM Models With 4L60 Or 4L60-E Transmission (ATRA TSB No. 449)

Vehicles equipped with 4L60 or 4L60-E transmission may leak fluid out transmission vent. Fluid may splash out vent due to high fluid level. Fluid may also be pumped out due to an oil pump that is not flat or has been machined, and now bolts are too long, allowing converter charge pressure to squeeze into vent cavity. To correct this condition, check oil pump surface for flatness. Repair as necessary. Ensure both stator support pump bolts and oil pump-to-case bolts are not too long. It may be necessary to add washers to bolts. Apply a thin sealant to vent cavity surface area of oil pump and stator support, located between 9 and 10 o'clock position on pump body. see scheme 23

All Models With 4L60-E Transmission

Transmission may show signs of overheating or torque converter is discolored. This condition may be caused by regulated apply oil not available due to a TCC PCM solenoid filled with debris, which does not allow TCC signal oil to lubricate TCC regulator apply valve in valve body. No DTCs are stored, as TCC PWM solenoid is still working electronically. To eliminate the possibility of this condition, TCC regulator apply valve should be machined to create 2 flat surfaces on opposite sides of first land on valve. Machined surface should be even with wide head of valve. See No. 37 in Fig. see scheme 24. Machining valve will completely bypass TCC regulator apply valve, provide a more positive lock up apply feel and guarantee apply oil is always available.

Manufacturer has made several design changes to 1998 4L60-E transmission. For improved drain back to reduce aeration of fluid, transmission case has a larger cutout between 2 slots located above 1-2 accumulator piston (at No. 1 check ball). see scheme 5 The 1998 design removed one slot to increase cutout size. A NEW Black manual shaft has enhanced coating. Case extension housings are more rigid for improved durability. Pressure Control Solenoid (PCS) has NEW design filter screen. Input sun gear to forward sprag inner race is a press fit design. Transmission oil pan has a deep design with improved oil filter. Control valve body has a chamfered edge for different dipstick stops. Dipstick stop has 2 different designs for regular or deep oil pan design.

OIL PUMP INTERCHANGE

Note. On GM vehicles with 4L60-E transmission, oil pump bodies have various designs. Ensure components are not mismatched when pump components are replaced.

1993-94

Pump body uses a 10 vane rotor and slide assembly. This pump body has the same casting and worm track configuration as 1985-1993 models. Pump cover has a larger diameter filter seal bore.

1995-96

Pump body also uses a 10 vane rotor and slide assembly, but this pump body has a different casting and worm track configuration than 1993-94 models and is not interchangeable. Pump body is identified by "PWM" cast into front side of pump body. Bolt-on bellhousing also was introduced in 1996 and requires added flange to center bellhousing during installation. Pump cover has a different casting and worm track configuration from 1993-94 models and is not interchangeable. Pump cover also includes "PWM" cast into back side of cover.

1997

Pump body has same worm track configuration as 1995-96 models, but a 13 vane rotor and slide assembly is used. The 13 vane slide has longer porting slots. Pump body also has "PWM" cast into front side. Pump cover has same worm track configuration as 1995-96 models, but porting slots are a different configuration from 1995-96 pump cover to accommodate changes in 13 vane and rotor and slide. Pump cover is identified by "13 V" cast into back side of pump cover. Pump cover is not interchangeable with other year models.