Overhaul - 4L60/4L60-E: Other Chevrolet Pickup C2500

VALVE BODY

1st Gear Only, No Upshift

On 4L60 only, check governor assembly. Governor valve sticking. Driven gear loose or damaged. Drive gear retaining pin missing. Nicks or burrs on output shaft, governor sleeve or case bore. Improper support pin length. Governor weights or springs missing, damaged or binding.

On 4L60/4L60-E, 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. Governor screen restricted or damaged. 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. On 4L60-E only, check shift solenoids.

1st Gear Start In 2nd Gear Start Mode (Camaro & Firebird Only)

On 4L60-E only, check second gear start switch. Check technical service bulletins.

Slips in 1st

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 housing and shaft 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. Binding or broken T.V. cable (4L60). On 4L60/4L60-E, 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.

Improper 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. Porosity in piston or auxiliary valve body. Abuse valve stuck in auxiliary valve body (4L60).

High Or Low 1-2 Shift Speeds

On 4L60 only, check T.V. cable binding, broken or improperly adjusted. Governor assembly valve sticking. Driven gear loose or damaged. Drive gear retaining pin missing. Nicks or burrs on output shaft, governor sleeve or case bore. Improper support pin length. Governor weights or springs missing, damaged or binding.

Throttle lever and bracket assembly damaged, binding or not installed properly. T.V. link missing, binding or damaged. Valve body face not flat, T.V. exhaust check ball stuck or T.V. plunger sticking. Oil pump assembly or case face not flat.

Slipping Or Rough 1-2 Shift

On 4L60 only, check throttle lever and bracket assembly damaged, not installed properly or T.V. cable broken or binding. Valve body assembly throttle valve sticking. T.V. bushing turned in bore. On 4L60/4L60-E, check defective valve body assembly. 1-2 shift valve train, line bias valve, accumulator valve or T.V. limit valve stuck. Gaskets or spacer plate incorrect, damaged or not installed properly. Body face not flat.

Defective 2-4 servo assembly. Apply pin incorrect length. 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

Internal converter damage. On 4L60 only, governor valve sticking. Drive gear retaining pin missing or loose. Governor weights binding. Governor drive gear damaged. Support pin in case incorrect length. On 4L60/4L60-E, oil pump stator shaft sleeve scored or not located properly. Valve body 2-3 valve train or accumulator valve stuck. Spacer plate or gaskets incorrect, damaged or not positioned properly. Throttle valve or T.V. limit valve stuck. Input housing assembly forward or 3-4 clutch plates worn. Excessive clutch plate travel.

Forward or 3-4 piston seals damaged. Porosity in 3-4 clutch housing or piston, or 3-4 piston check ball stuck, damaged or not sealing. Restricted apply passages. Forward clutch piston or 3rd accumulator retainer and ball assembly not seating. Sealing balls loose or missing. 2-4 servo assembly or 2nd apply piston seals missing or damaged.

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

On 4L60-E only, check shift solenoids for dirt, damaged seals or electrical connections.

3rd Gear Only

On 4L60-E only, check 2-3 shift solenoid and 3-2 control solenoid circuits, damaged seals or electrical connections.

3-2 Flare Or Tie Up

On 4L60-E only, check 3-2 control solenoid for dirt, damaged seals or electrical connections.

Slipping, Rough or No 3-4 Shift

On 4L60 only, check governor weights for binding. Governor valve sticking. Drive gear damaged or retaining pin missing or loose. Support pin in case incorrect length. On 4L60/4L60-E, check oil pump assembly faces not flat or pump cover retainer and ball assembly omitted or damaged. Valve body assembly 2-3 valve train, accumulator valve, throttle valve, T.V. limit valve (4L60 only), 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 "R" Or Slips In "R"

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 oil pump assembly. Retainer and ball assembly missing or damaged. Stator shaft seal rings or ring grooves damaged. Stator shaft sleeve scored or damaged. Reverse boost valve stuck, damaged or not assembled properly. Cup plug missing.

Restricted oil passage. Faces not flat. Converter clutch apply valve stuck. 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. On 4L60 only, auxiliary valve body low overrun valve stuck. Cup plug restricted, missing or damaged.

No Part-Throttle Or Delayed Downshifts

On 4L60 only, T.V. cable loose or not adjusted properly. T.V. bracket assembly bent. On 4L60/4L60-E, 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. Governor weights binding or governor valve stuck (4L60 only). Defective valve body assembly. Throttle valve, 3-2 control valve stuck. On 4L60 only, T.V. modulated downshift valve stuck. T.V. sleeve turned in bore. On 4L60/4L60-E, 4-3 sequence valve body channel blocked. No. 5 check ball missing.

Harsh Garage Shifts

On 4L60-E only, check valve body for missing check ball, or orifice cup plug.

No Overrun Braking in Manual 3-2-1

T.V. cable loose or not adjusted properly (4L60 only). 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"

On 4L60-E only, governor support pin too long or missing or governor valve stuck. On 4L60/4L60-E, forward sprag clutch assembly installed backward.

No Park

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

Oil Pressure High or Low

Perform PRELIMINARY CHECKING PROCEDURE. See CONTROL PRESSURE TEST under TESTING . Oil pressure regulator valve stuck or valve spring damaged. Rotor guide omitted or not assembled properly. Rotor cracked or broken. T.V. (4L60 only) or reverse boost valve or sleeve stuck, damaged or not assembled properly. Orifice valve 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 grease used during rebuild procedure. On 4L60 only, T.V. exhaust ball stuck or damaged. On 4L60/4L60-E, throttle link, lever and bracket assembly binding, damaged or not assembled properly.

Manual valve scored or damaged. Spacer plate or gaskets incorrect, damaged or not assembled properly. Face not flat. On 4L60 only, throttle valve or T.V. limit valve sticking. Modulated downshift valve, line bias valve or 2-3 shift valve stuck. On 4L60-E only, check for stuck 2-3 solenoid valve, damaged pressure control solenoid or damaged pressure switch assembly. On 4L60/4L60-E, check for missing check balls or wrong assembly. Case-to-valve body face not flat.

Harsh Shift Points

On 4L60-E only, check PCM input signals from TPS, pressure switch assembly, fluid temperature switch, 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

On 4L60 only, T.V. cable binding or not adjusted properly. T.V. exhaust ball stuck or damaged. Throttle lever and bracket assembly binding, damaged or not assembled properly. Pressure regulator valve or T.V. boost valve stuck. Pump slide sticking.

Throttle valve or plunger sticking. Modulated T.V. upshift or downshift valves, T.V. limit valve or line bias valve sticking. Spacer plate or gaskets damaged, incorrect or not assembled properly.

Valve body pad porous or damaged. Governor filter restricted 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.

On 4L60-E only, 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.

Note. Models with 4L60-E use Powertrain Control Module (PCM) computer, which controls TCC, pressure control solenoid and shifting solenoids 1-2 and 2-3. Models with 4L60, use PCM to control TCC only.

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 switch damaged. Engine speed sensor or pressure switch assembly (4L60-E only). 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. Flash restricting 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.

Converter Clutch Apply Cold

On 4L60-E only, check engine coolant temperature sensor and trouble codes.

Oil Leaking Out Vent

Chamfer in pump body rotor pocket too large. T.V. limit valve stuck (4L60 only). 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.

No Reverse, Slips in Reverse, Bad Engagement (No Braking or Weak Braking in Manual Low)

No. 5 check ball missing. Faulty low-reverse clutch. Reverse boost valve sticking. Reverse boost valve installed backward.

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.

Slip on 2-3 Shift, Falling Out of 3rd, Repeated 3-4 Clutch or 2-4 Band Failure

Leaking No. 7 check ball (direct clutch accumulator check valve located in case, visible through servo). Cracked input shaft. Input shaft sealing rings leaking. Leak at base of input shaft where shaft is pressed into drum. Pump cover bore (sealing ring surface) worn. Servo air bleed cup plug loose or blown out of case. Pump-to-case gasket misaligned or ripped. 3-4 air bleed ball in back of input drum leaking. 3-4 clutch piston seals leaking. Servo release side (large) sealing ring leaking in 2nd gear and dragging 3rd clutch. Band apply pin in case worn. Servo seized in case. Damaged pump. Stator sleeve turned in pump and partly blocking feed passage. Throttle valve sticking, causing delayed 3rd clutch circuit pressure rise during 2-3 shift.

Delayed or No Forward Clutch Engagement, Slips or Chatters in 1st Gear

Leak at forward clutch accumulator (auxiliary valve body; on 4L60) caused by accumulator pin "walking" out of oval hole in cover.

No 4th Gear, No 3-4 Upshift (Stays in 3rd, 2nd Usually Okay)

Leaking 4th gear piston sealing ring (inside servo cover). Excessive servo clearance allowing 4th piston to "walk" out of cover, leaking 4th apply oil out servo vent hole. Servo vent hole blocked (hole is at pan gasket surface). Leaking 4th signal switch. 3-4 relay valve installed backward. Aluminum disc missing from between 3-4 relay valve and hole pin. Servo feed tunnel cup missing from valve body. 3-4 shift valve stuck. Incorrect spring or spring too stiff at 3-4 shift valve. 3-4 accumulator air bleed cup plug blown out of case. Throttle valve sticks.

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. Stuck 2-3 shift valve. Servo pin jammed in case. Stuck 3-4 relay or 4-3 sequence valve.

No Reverse

Reverse input drum cracked at weld or seals damaged.

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.

Preliminary Checking Procedure

1. Ensure fluid level is correct and engine is in good operating condition before performing control pressure test. Ensure shift linkage is properly adjusted. See appropriate AUTO TRANS SERVICING article in the AUTOMATIC TRANS SERVICE section. See menu below.
2. Control pressure can be checked to ensure proper throttle valve cable adjustment. If control pressure is not within specification, adjust throttle valve cable before attempting any other corrections. See THROTTLE VALVE CONTROL PRESSURE CHECK.

Throttle Valve Control Pressure Check

1. Install pressure gauge on transmission line pressure tap. (Scheme 19) Install tachometer on engine. Apply parking brake. Ensure engine is at normal operating temperature.
2. Operate engine at 1000 RPM. With gear selector in "P" position, note oil pressure reading. Move gear selector to "D" position, and note oil pressure reading.
3. Oil pressure "D" reading must be equal to "P" reading or must not exceed it by more than 10 psi (.70 kg/cm). Operate engine at 1400 RPM. Oil pressure should increase. Adjust throttle valve cable if pressure does not increase. See appropriate AUTO TRANS SERVICING article in the AUTOMATIC TRANS SERVICE section. See menu below. For Astro, see «TRANSMISSION SERVICING - A/T»(ref-55691) For 1993 Blazer C/K 4WD, see «TRANSMISSION SERVICING - A/T»(ref-55691) For Blazer S/T, see «TRANSMISSION SERVICING - A/T»(ref-55691) For 1993 Camaro, see «TRANSMISSION SERVICING - A/T»(ref-55695) For 1994 Camaro, see «TRANSMISSION SERVICING - A/T»(ref-55696) For 1993 Caprice, see «TRANSMISSION SERVICING - A/T»(ref-55695) For 1994 Caprice, see «TRANSMISSION SERVICING - A/T»(ref-55696) For 1993 Corvette, see «TRANSMISSION SERVICING - A/T»(ref-55695) For 1994 Corvette, see «TRANSMISSION SERVICING - A/T»(ref-55696) For 1993 Firebird, see «TRANSMISSION SERVICING - A/T»(ref-55695) For 1994 Firebird, see «TRANSMISSION SERVICING - A/T»(ref-55696) For 1993 Fleetwood Brougham, see «TRANSMISSION SERVICING - A/T»(ref-55695) For 1994 Fleetwood Brougham, see «TRANSMISSION SERVICING - A/T»(ref-55696) For GMC Vans, see «TRANSMISSION SERVICING - A/T»(ref-55691) For GMC Suburban, see «TRANSMISSION SERVICING - A/T»(ref-55691) For GMC Pickup, see «TRANSMISSION SERVICING - A/T»(ref-55691) For 1993 Impala SS, see «TRANSMISSION SERVICING - A/T»(ref-55695) For Jimmy, see «TRANSMISSION SERVICING - A/T»(ref-55691) For 1993 Roadmaster, see «TRANSMISSION SERVICING - A/T»(ref-55695) For 1994 Roadmaster, see «TRANSMISSION SERVICING - A/T»(ref-55696) For Safari, see «TRANSMISSION SERVICING - A/T»(ref-55691) For Yukon, see «TRANSMISSION SERVICING - A/T»(ref-55691)

Scheme 18

Minimum Throttle Valve Pressure Check

1. Ensure throttle valve cable is properly adjusted. Attach pressure gauge to line pressure tap. (Scheme 19) Apply parking brake and service brakes.
2. Check line pressure as specified. (Scheme 20) Pressure readings must be within specification. If pressure reading is not within specification, see «TROUBLE SHOOTING»(ref-25406-S30918094212001100100000).

Full Throttle Valve Pressure Check

1. Attach pressure gauge to line pressure tap. (Scheme 19) Apply parking brake and service brakes. Ensure throttle valve cable is secured in fully extended position.
2. Check line pressure as specified. (Scheme 20) Pressure readings must be within specification. If pressure reading is not within specification, see «TROUBLE SHOOTING»(ref-25406-S30918094212001100100000).

Pressure Differential Check

1. Possible leakage in clutch circuits may be determined by checking oil pressure differential between line pressure and 2nd, 3rd and 4th clutches. Attach pressure gauges to line pressure tap and appropriate clutch circuit tap on transmission.
2. Circuit tap for 2nd clutch is located on right rear side of transmission, above pan. Circuit tap for 3rd clutch is located next to 2-4 servo, above 4th clutch circuit tap. see scheme 1 Drive vehicle, and note both pressure readings. Pressure differential between line pressure and clutch circuits exceeding 10 psi (0.70 kg/cm 2 ) indicates possible leakage in clutch circuit.

Scheme 19

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.

END PLAY CHECK

1. Inspect torque converter for hub scoring, cracks or weld area cracks before checking end play. Install End Play Checking Tool (J-35138) on torque converter. see scheme 14
2. Note end play of torque converter. End play must be within specification. See «TORQUE CONVERTER END PLAY SPECIFICATIONS»(ref-25406-S24366246132001100100000) table. Replace torque converter if end play is not within specification or damage to hub area exists.

TORQUE CONVERTER END PLAY SPECIFICATIONS

Scheme 20

CHECKING SERVO PIN LENGTH

1. Remove 4th apply piston and return spring. (Scheme 22) Remove retainer ring, washer, apply pin spring and 2nd apply piston pin. Install Piston Compressor (J-22269-01) on 2nd apply piston. (Scheme 23)
2. Remove retainer ring, cushion spring and spring retainer. Install Band Apply Pin Tool (J-33037) and apply pin. (Scheme 24) 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-25406-S33246119622001100100000) table under 2-4 BAND & SERVO ASSEMBLY under «TRANSMISSION REASSEMBLY»(ref-25406-S17028249152001100100000).

Scheme 21

Scheme 22

Scheme 23

EXTENSION HOUSING

1. On 4L60 models, remove governor assembly. On models with mechanical speedometers, remove retaining bolt, washer and retainer. Remove speedometer driven gear assembly, driven gear and "O" ring.
2. On models with internal speed sensor, remove retaining bolt and washer. Remove speed sensor assembly and "O" ring. Remove extension housing and seal. Remove output shaft sleeve and "O" ring (if equipped). Speed sensor rotor must be removed from output shaft.
3. Install Gear Puller (J-21427-01) and Adapter (J-8433) on rotor. Pull rotor from output shaft. On models with mechanical speedometers, push retaining clip tab. Remove speedometer gear from output shaft.
4. On 4L60-E models, remove speed sensor assembly. Remove extension housing and seal.

VALVE BODY & AUXILIARY VALVE BODY (4L60 ONLY)

Remove valve body and auxiliary valve body (4L60). See VALVE BODY and AUXILIARY VALVE BODY (4L60 ONLY) under ON-VEHICLE SERVICE. Note bolt length and location during removal. Note check ball location for reassembly reference. see scheme 5and see scheme 9.

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.
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 10and (Scheme 25) for check ball and filter locations.

Scheme 24

TRANSMISSION END PLAY CHECK

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

1. Install Pump Remover/End Play Fixture (J-24773-A) and End Play Adapter (J-25022-A) on end of turbine shaft. (Scheme 26)
2. Clamp dial indicator on long bolt with indicator tip on end play fixture. Measure transmission end play. Transmission end play should be.005-.036" (.13-.91 mm).

Scheme 25

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 pump assembly free from case.
2. Remove oil pump seal and gasket. Remove reverse input clutch-to-pump thrust washer from pump. Lift out turbine shaft with reverse and input clutch assembly.

2-4 BAND & INPUT GEAR SET

1. Remove band anchor pin from case. (Scheme 27) Remove 2-4 band assembly from case. Remove input sun gear. (Scheme 28) CAUTION: Output shaft must be held in place when removing input carrier retaining ring.
2. Install Output Shaft Support (J-29837) on output shaft. (Scheme 29) Remove input carrier to output shaft retaining ring. Remove input carrier. Remove output shaft. Remove input carrier thrust washer from reaction carrier shaft.

Scheme 26

Scheme 27

Scheme 28

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 retaining ring.
2. Remove spring retainer from low-reverse support. Remove reaction sun gear, low-reverse clutch race, clutch roller, support assembly and reaction carrier assembly. (Scheme 29)
3. Remove low-reverse clutch assembly. Note locations of parts. Remove internal reaction gear and bearing assembly. Remove internal reaction support-to-case bearing assembly.

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.
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 30)

Scheme 29

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.

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. (Scheme 21) Pour clean solvent in bore. Inspect for leaks in transmission case. Replace check valve assembly if it leaks. see scheme 25 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. see scheme 25

Scheme 30

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

AUXILIARY VALVE BODY (4L60 ONLY)

1. Place transmission in a vertical position. Install seals on low-reverse clutch piston. Apply petroleum jelly to seals.
2. 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.
3. 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 28) Ensure clutch plates are proper thickness.
4. Install clutch plates. See «LOW-REVERSE CLUTCH PLATE USAGE»(ref-25406-S37492615232001100100000) 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 friction plates and 4 steel plates alternately, starting with friction plate.
5. 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.
6. Place spacer plate between waved plate and first friction clutch plate with identification facing upward. Measure overall height of clutch pack. Overall height should be 1.20-1.24" (30.5-31.5 mm). Install clutch pack assembly in transmission case.
7. 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 retainer ring.

LOW-REVERSE CLUTCH PLATE USAGE

SPACER PLATE SELECTION (1) (4L60)

SPACER PLATE SELECTION (1) (4L60-E)

REACTION & INPUT GEAR SETS

1. Install snap 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 28)
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 case as an assembly. Align 3-4 clutch plates of input assembly with input internal gear. Assembly is fully seated when reverse housing is just below oil pump face of case.

SEALS, BEARINGS & THRUST WASHERS

Note. To identify seals, bearings and thrust washers locations (Scheme 32)

Scheme 31

Scheme 32

1. Turbine shaft seals should be installed just before oil pump installation. Position Seal Installer (J-36418-1) on input shaft. see scheme 33 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 pump into case, aligning filter and pressure regulator holes with holes in case. Install retaining bolts. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-25406-S12225658012001100100000) table. 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 under «TRANSMISSION DISASSEMBLY»(ref-25406-S04458057762001100100000). 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-25406-S14704574452001100100000) 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 check balls and oil screens in proper locations. Install special retainer and ball assembly. see scheme 10and (Scheme 25) for 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-25406-S12225658012001100100000) table.

VALVE BODY & AUXILIARY VALVE BODY

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

1. Install speed sensor wheel/speedometer gear and retaining clip on output shaft. On 4L60, if output shaft has 2 locating holes, use hole nearest yoke on Corvette only. Install "O" ring in output shaft sleeve.
2. On all models, install output sleeve on output shaft. DO NOT position output sleeve past machined surface of output shaft. Install seal ring on extension housing.
3. Position extension housing on transmission case. Install retaining bolts. Install oil seal in extension housing.
4. Install speed sensor/speedometer driven gear and fitting assembly. Install retainer and bolt. Tighten bolt to specification. See «TORQUE SPECIFICATIONS»(ref-25406-S12225658012001100100000) table. Install outside electrical connector and manual shift lever.