GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2007 🢒 Lucerne 🢒 Transmission/Transaxle 🢒 Automatic Transaxle - 4T65-E 🢒 Torque Converter Replacement Guide

Condition

Action

Fluid

  • Transmission Fluid Oxidized/Discolored
    • No metal debris
    • Clutch fiber material

Do not replace the torque converter.

Refer to Transmission Fluid Check .

  • Transmission Fluid Contaminated with Engine Coolant/Oil

Replace the torque converter.

Refer to Torque Converter Cover Replacement .

  • Transmission Fluid Contaminated with Sludge/Metal Particles
    • Replace the torque converter if the following conditions are found:
       - Pump Damage
       - Drive sprocket support damage
       - Turbine/stator shaft damage
       - No damage found in transmission
    • Do not replace the torque converter for other transmission component damage.
  • Fluid Leaks from Torque Converter
    • Perform the powder/dye leak check.
        Refer to Fluid Leak Diagnosis .
    • Replace the torque converter if the following conditions are found:
       - Leak present at weld areas-hub, lug, or closure weld
       - Hub surface is damaged-scored, raised/transferred metal
       - Bushing is damaged

Function/Appearance

  • Torque Converter Discolored/Overheated

Replace the torque converter.

Refer to Torque Converter Cover Replacement .

  • Broken/Cracked Flexplate

Replace the torque converter.

Refer to Torque Converter Cover Replacement .

  • Stripped Converter Bolt Holes

Replace the torque converter.

Refer to Torque Converter Cover Replacement .

  • Torque Converter Pilot Damaged

Replace the torque converter.

Refer to Torque Converter Cover Replacement .

  • Torque Converter Ballooning

Replace the torque converter if end play exceeds 0.7 mm (0.3 in) using J 35138 .

Driveability - Non TCC

  • Harsh Gear Shifts-Non TCC

Do not replace the torque converter.

Refer to Symptoms - Automatic Transmission .

  • No Drive/Slips in Drive-Non TCC

Do not replace the torque converter until completing all engine and transmission diagnostics.

Refer to Slips in Drive or No Drive .

  • Idle Surge/Rough Idle

Do not replace the torque converter. Refer to Symptoms - Engine Controls

  • Poor Acceleration above 48 km/h (30 mph) - Launch

Do not replace the torque converter until completing all engine and transmission diagnostics. Refer to the following:

  • DTC P0741-TCC Stuck OFF/High Slip-Intermittent Only

Do not replace the torque converter.

Refer to DTC P0741 diagnostic table.

  • DTC P0741-TCC Stuck OFF/High Slip

Refer to DTC P0741 diagnostic table.

  • DTC P0742 -TCC Stuck ON

Do not replace the torque converter.

Refer to DTC P0742 diagnostic table.

  • TCC Apply/Release Shudder

Refer to Converter Clutch Apply Rough, Slips, or Shudders .

  • TCC Chuggle
    • Refer to Symptoms - Engine Mechanical.
    • Refer to Symptoms - Engine Controls .
    • Refer to Symptoms - Automatic Transmission .

Noise and Vibration

  • Noise-Whine
    • Refer to Symptoms - Automatic Transmission .
    • Do not replace the torque converter if noise is present in NEUTRAL/PARK.
        Refer to Symptoms - Engine Mechanical .

Vibration - Out of Balance
    • Refer to Vibration Analysis - Engine.