NO SECOND GEAR THM 125C HYDRA-MATIC 3T40

Models 1988-89 6000, SUNBIRD, GRAND AM, Affected: FIERO AND LeMANS EQUIPPED WITH THM 125C/HYDRA-MATIC 3T40

BULLETIN COVERS:

A No Second Gear condition that may be caused by a rough surface finish on the Intermediate Servo Cover Piston Bore (137) . This finish will wear the lip off the (inner) Intermediate Servo Seal (132), causing a leak in the piston bore. This leak may cause Intermediate Band (606), and Direct Clutch (608 - 617) wear.

SERVICE ACTION:

If a customer comments about a No Second Gear condition in any THM 125C/HYDRA-MATIC 3T40, the Intermediate Band and Direct Clutch Assembly should be inspected for possible wear. To service this condition on a 1988 or 1989 125C/HYDRA-MATIC 3T40, inspect for a worn inner lip seal and cover surface machine finish. If the finish is rough, install a new Intermediate Servo Cover and Intermediate Servo oil ring seals (inner and outer).

SERVICE NOTES:

Do not attempt to sand the intermediate servo cover bore machine finish with Crocus cloth, soft stone or any other smoothing material.

SERVICE PARTS INFORMATION:

When ordering a new Intermediate Servo Cover and Intermediate Servo oil ring seals (inner and outer), refer to the following part list:

Intermediate Intermediate Servo Piston and Seals Servo Cover ---------------------- ------------- .79 Ratio - 8652901 .79 Ratio - 8631702 .71 Ratio - 8652900 .71 Ratio - 8631703 .64 Ratio - 8652911 .64 Ratio - 8631704

Parts are currently available from GMSPO.

SERVICE MANUAL REFERENCE:

When servicing any 125C/HYDRA-MATIC 3T40 refer to the procedures outlined in the Unit Repair Section of your Service Manual.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.