A/T - No Second Gear
88chevy30Number: 89-49-7A
Section: 7A
Date: DEC., 1988
Subject: NO SECOND GEAR
Model and Year: 1988-89 CELEBRITY, CAVALIER, CORSICA, BERETTA
WITH THM-125C TRANSAXLE
TO: ALL CHEVROLET DEALERS
This bulletin covers a No Second Gear condition that may be caused by a rough surface finish on the Intermediate Servo Cover Piston Bore. This finish will wear the lip off the (inner) Intermediate Servo Seal, causing a leak in the piston bore. This leak may cause Intermediate Band, and Direct Clutch 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 part list on the following page.
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
Note: 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.