This is the master index to everything we've written about transmissions. Bookmark this page. Use it as your reference for any trans topic.
Identifying your transmission
Start here:
- How to Identify Your Transmission — by VIN, RPO, year, application
Then check specific guides:
Diagnosis
Warning signs:
- 10 Transmission Warning Signs — catch problems early
- Transmission Shudder vs Slip — tell the difference
- Transmission Noise Diagnosis — hum, whine, click decoded
Pan inspection:
- Transmission Pan Inspection — what the pan tells you
Pressure testing:
- Transmission Line Pressure Testing — gold-standard diagnosis
Codes:
- How to Read Transmission Codes — P-code guide
- 4L60E Common Failure Codes
- 4L80E Common Failure Codes
- 6L80 Common Failure Codes
Fluid:
- How to Check Transmission Fluid
- Burnt Transmission Fluid: What to Do
- How to Identify Transmission Fluid
- Transmission Fluid Types
- 6L80 Fluid Check Procedure
Failure modes
Clutch vs band vs hard part:
- Transmission Failure Modes — what failed and how to fix
Specific transmission rebuild guides
GM 4-speed:
GM 6-speed:
- Best 6L80 Rebuild Kit
- 6L80 Rebuild Cost
- 6L80 Mechatronics Rebuild
- 6L80 Wave Plate Replacement
- 6L80 Input Drum Failure
- 6L80 Thrust Washer Wear
- 6L80 P0775 Solenoid Codes
Ford:
Dodge/Cummins:
- Best 68RFE Rebuild Kit
- 68RFE Billet Input Shaft
- 68RFE Flexplate
- 68RFE Pressure Control Solenoid
- 68RFE Input Bushing
- 47RE/48RE Direct Clutch
Allison:
Classics:
Specific part guides
4L60E specific:
- 4L60E No Reverse / Sun Shell Fix
- 4L60E TCC Apply Piston
- 4L60E TCC Solenoid
- 4L60E Pump Rebuild
- 4L60E PR Valve Symptoms
- Sonnax PR Valve Install Guide
- 4L60E Reverse Input Drum
- 4L60E Governor Pressure Switch
- 4L60E TPS Effect on Shifts
- 4L60E Slipping Diagnosis
- 4L60E 3-4 Clutch Pack
4L80E specific:
- 4L80E PWM Solenoid
- 4L80E Shift Solenoid Replacement
- 4L80E Center Support
- 4L80E Pump Alignment
- 4L80E Direct Clutch HD Upgrade
- 4L80E Intermediate Band
- 4L80E Intermediate Sprag
- 4L80E Vacuum Modulator
Transmission comparisons
Direct comparisons:
- 4L60E vs 4L80E
- 4L80E vs 6L80
- 4L60E vs 6L80
- TH400 vs 4L80E
- 4R75W vs 4R70W
- 4L80E vs 6L90
- Allison 1000 vs 68RFE
- Allison vs 68RFE vs 6R140
Swap guides
Transmission swaps:
- LS Swap Transmission Guide
- 4L60E to 4L80E Swap
- TH400 to 4L80E Swap
- TH350 vs 700R4 Swap
- 4L60E to 4L65E Conversion
- 4L80E Swap Into Chevy
- Swap Planning Checklist
Cooling system
Heat management:
- Transmission Overheats in Traffic
- Transmission Cooler Installation
- Transmission Temperature Monitoring
- Diesel Cooler Sizing
- Transmission Cooler Line Leak
- Cooler Line Types
- Deep Transmission Pan
Service procedures
Maintenance:
- How to Flush Transmission Fluid
- Transmission Filter Guide
- Transmission Seal Kit Guide
- Transmission Bushing Kit
- Transmission Mount Failure
- Tow Rig Daily Maintenance
- Trans Ground Strap
- Trans Seal vs Gasket
Tow rig setup
HD applications:
- Diesel Tow Rig Setup
- 4L80E Direct Clutch HD
- Allison 1000 C2 HD
- 47RE/48RE Direct Clutch HD
- 4R70W Servo Upgrade
Performance upgrades
Shift kits and tuning:
Torque converters:
HD parts deep dives:
Rebuild process
Process guides:
- Transmission Rebuild Break-In
- 10 Transmission Rebuild Mistakes
- Transmission Rebuild Tool List
- Transmission Parts Buying Guide
Vehicle-specific applications
LS swap considerations:
Buying used trucks:
Misc valuable topics
Speed sensors:
Other repairs:
This is your starting point. Use this index to navigate to any transmission topic. New articles published regularly.
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