- Overhaul Procedure Steps

NOTE: This article lists the sequential steps necessary to overhaul the transmission.
^ For the specific step listed below, refer to the hyperlink for that step.
^ For the complete list of procedures, refer to "Repair Instruction". Overhaul

OVERHAUL PROCEDURE 4T80-E TRANSAXLE:

Torque Converter and Oil Pump Drive Shaft Removal.
Torque Converter and Oil Pump Drive Shaft Removal

Holding Fixture Install.
Holding Fixture Install

OSS Sensor and Cooler Fitting Removal.
OSS Sensor and Cooler Fitting Removal

Fourth Servo Removal.
Fourth Servo Removal

Final Drive End Play Measurement.
Final Drive End Play Measurement

Case Extension and Scavenge Pipe Removal.
Case Extension and Scavenge Pipe Removal

Differential Carrier and Housing Removal.
Differential Carrier and Housing Removal

Output Shaft Removal.
Output Shaft Removal

Final Drive Carrier, Sun and Internal Gear Removal.
Final Drive Carrier, Sun and Internal Gear Removal

Bottom Pan, Gasket, and Scavenge Screens Removal.
Bottom Pan, Gasket, and Scavenge Screens Removal

Lower Control Valve Body Assembly Removal.
Lower Control Valve Body Assembly Removal

Input Shaft End Play Measurement (1).
Input Shaft End Play Measurement

Side Cover, Gasket, and Filter Removal.
Side Cover, Gasket, and Filter Removal

Oil Pump, Upper Control Valve Assembly Removal.
Oil Pump, Upper Control Valve Assembly Removal

Case Cover Removal.
Case Cover Removal

Drive/Driven Sprocket and Chain Removal.
Drive/Driven Sprocket and Chain Removal

Input Speed Sensor and Wiring Harness Removal.
Input Speed Sensor and Wiring Harness Removal

2ND Clutch Plates and Reverse Clutch Removal.
2ND Clutch Plates and Reverse Clutch Removal

4TH Band and 3RD Clutch/Reaction Shell Removal.
4TH Band and 3RD Clutch/Reaction Shell Removal

Parking Pawl Removal.
Parking Pawl Removal

Forward Clutch ASM and Low Reverse Band Removal.
Forward Clutch ASM and Low Reverse Band Removal

Manual Shaft Assembly Removal.
Manual Shaft Assembly Removal

Case Inspection.
Case Inspection

Drive Sprocket Support and Seal Replacement.
Drive Sprocket Support and Seal Replacement

Forward and Coast Clutch Assembly Overhaul.
Forward and Coast Clutch Assembly Overhaul

Fretting Ring Inspection and Installation.
Fretting Ring Inspection and Installation

Forward and Coast Clutch Installation.
Forward and Coast Clutch Installation

Final Drive Gear and Snap Ring Inspect/Install.
Final Drive Gear and Snap Ring Installation

Forward Clutch Support Stud Installation.
Forward Clutch Support Stud Installation

Parking Pawl and Pivot Pin Install.
Parking Pawl and Pivot Pin Install

Third Clutch and Reaction Carrier.
Third Clutch and Reaction Carrier Disassemble

Third Clutch and Reaction Carrier Inspect/Assemble.
Third Clutch and Reaction Carrier Inspect/Assemble

Reaction Carrier/Shell and 3RD Clutch Installation.
Reaction Carrier/Shell and 3RD Clutch Installation

4TH Band Installation.
4TH Band Installation

Reverse Clutch Housing and 2ND Sprag Disassemble.
Reverse Clutch Housing and 2ND Sprag Disassemble

Rev Clutch Housing and 2ND Sprag Inspect/Assemble.
Rev Clutch Housing and 2ND Sprag Inspect/Assemble

Reverse Clutch Housing Installation.
Reverse Clutch Housing Installation

2ND Clutch Plates Inspection and Installation.
2ND Clutch Plates Inspection and Installation

Driven Sprocket Support Disassemble.
Driven Sprocket Support Disassemble

Driven Sprocket Support Inspect and Assemble.
Driven Sprocket Support Inspect and Assemble

Driven Sprocket Support Installation.
Driven Sprocket Support Inspect and Assemble

Drive Link and Sprockets Inspect/Assemble/Install.
Drive Link and Sprockets Inspect/Assemble/Install

Thrust Bearings Inspect and Install.
Thrust Bearings Inspect and Install

Case Cover Inspect and Install/Seal Replace.
Case Cover Inspect and Install/Seal Replace

Input Shaft End Play Measurement (2).
Input Shaft End Play Measurement

Upper Control Valve Body Disassemble and Inspect.
Upper Control Valve Body Disassemble and Inspect

Upper Control Valve Body Assemble.
Upper Control Valve Body Assemble

Upper Control Valve Assembly Installation.
Upper Control Valve Assembly Installation

Pump Disassemble.
Pump Disassemble

Secondary Pump Disassemble and Inspect.
Secondary Pump Disassemble and Inspect

Secondary Pump Assemble.
Secondary Pump Assemble

Pump Inspect and Assemble.
Pump Inspect and Assemble

Pump Installation.
Pump Installation

Temp Sensor, TCC Solenoid, and PCS Valve Assemble.
Temp Sensor, TCC Solenoid, and PCS Valve Assemble

Oil Filter and Side Cover Install.
Oil Filter and Side Cover Install

Lower Control Valve Body Assembly Disassemble.
Lower Control Valve Body Disassemble and Inspect

Channel Plate Inspect and Assemble.
Channel Plate Inspect and Assemble

Lower Control Valve Body Disassemble and Inspect.
Lower Control Valve Body Disassemble and Inspect

Lower Control Valve Body Inspect and Assemble.
Lower Control Valve Body Inspect and Assemble

Lower Control Valve Body and TFP Switch Install.
Lower Control Valve Body and TFP Switch Install

Accumulator Housing Disassemble and Inspect.
Accumulator Housing Disassemble and Inspect

Accumulator Housing Assemble and Installation.
Accumulator Housing Assemble and Installation

Lower Controls Assembly Installation.
Lower Controls Assembly Installation

Manual Link and Electrical Connectors Installation.
Manual Link and Electrical Connectors Installation

Scavenge Screens/Seals, Bottom Pan Inspect/Install.
Scavenge Screens/Seals, Bottom Pan Inspect/Install

Final Drive Carrier Inspect.
Final Drive Carrier Inspect

Differential Carrier Overhaul.
Differential Carrier Overhaul

Final Drive Carrier/Differential Carrier Install.
Final Drive Carrier/Differential Carrier Install

Output Shaft Inspect and Install.
Output Shaft Inspect and Install

Case Extension/Scavenge Pipe Inspect and Install.
Case Extension/Scavenge Pipe Inspect and Install

Final Drive End Play Measurement (2).
Final Drive End Play Measurement

4TH Servo Overhaul.
4TH Servo Overhaul

VSS Sensor and Cooler Fitting Inspect and Install.
VSS Sensor and Cooler Fitting Inspect and Install

Axle Seals Removal and Installation.
Axle Seals Removal and Installation

Torque Converter and Oil Pump Drive Shaft Install.
Torque Converter and Oil Pump Drive Shaft Install