Toyota shifting gremlin
Some customers may complain about an intermittent shudder when lightly accelerating after an upshift between 20 mph and 45 mph or before a downshift between 30 mph and 65 mph when the torque converter assembly is in flex lockup. Production changes to the torque converter have been implemented to improve this condition.
This applies to 2007-2008 Tundra vehicles equipped with a 6-speed automatic transmission and the 5.7L V8 engine.
- Connect the Techstream to the vehicle and perform Health Check. Confirm that no DTCs are stored in the ECM (SAE term: Powertrain Control Module/PCM). If any DTCs are present, this TSB does not apply. If no DTCs are present, proceed to Step 2.
- Test drive the vehicle and confirm the customer complaint of shudder.
- Use Techstream to take a snapshot when shudder occurs to confirm if shudder is taking place during flex lockup. Configure the snapshot as follows: 30 second duration; trigger point at midpoint.
- Use Data List and the graphing functions of Snapshot to confirm the following data parameter when the shudder condition occurs:
- Vehicle speed
- Shift status
- Lock up
- Lock up solenoid status
- SLU solenoid status
- If the shudder occurs with Lock Up “ON,”, Lockup solenoid status “OFF,” and SLU solenoid status “OFF,” then the shudder is related to torque converter flex lockup. Proceed to Step 5.
- If the shudder occurs with Lock Up “OFF,” Lock Up solenoid status “OFF,” and SLU solenoid status “OFF,” then the condition is not related to torque converter flex lockup and this TSB does not apply. Continue diagnosis to identify the root cause of the shudder.
- Replace the torque converter, referring to the appropriate Toyota repair manual.
- Adjust the transmission fluid level in the transmission.
- Test drive the vehicle and confirm that the shudder condition has been eliminated.
The replacement torque converter is available as part number 32000-0C030.