NO SECOND GEAR THM 125C HYDRA-MATIC 3T40

MODELS AFFECTED: 1988-89 THM 125C/HYDRA-MATIC 3T40, CENTURY, SKYHAWK, SKYLARK

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

IMPORTANT: Ratios listed are identifiers used in Service Parts Catalog for ordering purposes.

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.