| Subject: | Automatic Transmission/Transaxle Torque Converter Replacement |
| Models: | 2009 and Prior GM Passenger Cars and Trucks |
| 2009 and Prior HUMMER H2, H3 |
| 2009 and Prior Saturn Cars and Light Duty Trucks (Except VTi Equipped Vehicles (RPO M16 and M75) |
| with ALL Automatic Transmissions and Transaxles |
This bulletin is being revised to add the 2007-2009 model years. Please discard Corporate Bulletin Number 01-07-30-010B (Section 07 - Transmission/Transaxle).
The purpose of this bulletin is to help technicians determine when a torque converter should be replaced. Below is a list of general guidelines to follow.
The converter should NOT be replaced if the following apply:
| • | DTC P0742 - TCC stuck on is set. This code is almost always the result of a controls condition (i.e. stuck TCC solenoid/valve). Experience has shown that this code rarely indicates a mechanical concern within the torque converter. |
| • | The fluid has an odor or is discolored but no evidence of metal contamination. |
| • | Fine metal particles (traces of metal flakes/gray color to fluid ) are found in the converter. This is not harmful to the torque converter. |
| • | The vehicle has been exposed to high mileage. |
| • | A small amount of wear appears on the hub where the oil pump drive gear mates to the converter (RWD only). A certain amount of such wear is normal for both the hub and oil pump gear. Neither the converter nor the front pump assembly should be replaced. |
The torque converter should be replaced under any of the following conditions:
| • | The vehicle has TCC shudder and/or no TCC apply. First complete all electrical and hydraulic diagnosis and check for proper engine operation. The converter clutch may be damaged. Also, the converter bushing and/or internal O-ring may be damaged. |
| • | Evidence of damage to the oil pump assembly, pump shaft, turbine shaft, drive sprocket support and bearing, or metal chips/debris in the converter. |
| • | Metal chips/debris are found in the converter or when flushing the cooler and the cooler lines. |
| • | External leaks in the hub weld area, lug weld or closure weld. |
| • | Converter pilot is broken, damaged, or fits poorly into the crankshaft. |
| • | The converter hub is scored or damaged. |
| • | The transmission oil is contaminated with engine coolant, engine oil or water. |
| • | If excessive end play is found after measuring the converter for proper end play (refer to Service Manual). |
| • | If metal chips/debris are found in the fluid filter, or on the magnet, and no internal parts in the unit are worn or damaged. This indicates that the material came from the converter. |
| • | The converter has an unbalanced condition that results in a vibration that cannot be corrected by following Converter Vibration Procedures. |
| • | Blue converter or dark circular ring between lugs. This condition will also require a complete cleaning of the cooler and a check for adequate flow through the cooler. |
| • | Converter bearing noise determined by noise from the bell housing area in Drive or Reverse at idle. The noise is gone in Neutral and Park. |
| • | If silicon from the viscous clutch is found in the lower pan (4T80-E ONLY). |
