A/T - Harsh 1-2 Shifts

90chevy15
GMC NUMBER: 90-7A-63

GROUP: 7A Automatic Transmission
DATE: May, 1990

CORPORATE
NUMBER: 077117
SUBJECT: HARSH 1-2 SHIFTS - NEW VALVE BODY ASSEMBLY AND REAR ACCUM. SPRING

MODELS: 1989-90 C,K,R,VP TRUCKS AND G-VANS W/3L80 5.7L V8 TBI
BULLETIN COVERS:
Some HYDRA-MATIC 3L80 (THM 400) 5.7L V8 TBI models may experience a harsh 1-2 shift. A new Valve Body Assembly and Rear Accumulator Spring were released which improve the 1-2 shift feel.

DATE OF PRODUCTION CHANGE:
(See Figure Below) Beginning December 21, 1989 (Julian Date 355) all LMA, LWA and SAA 1990 HYDRA-MATIC 3L80 (THM 400) transmission models were built with the new Valve Body Assembly (49) and Rear Accumulator Spring (78).



SERVICE PARTS INFORMATION:
Important

BOTH PARTS MUST BE SERVICED TOGETHER. Parts are currently available from GMSPO.

SERVICE MANUAL REFERENCE:
Refer to the Unit Repair Section of the appropriate Service Manual for the proper replacement procedures.

WARRANTY INFORMATION:
For vehicles repaired under warranty use:

Labor Operation: T8165

Labor Time: 1.3 hrs.