C 1500 Truck 2WD V8-350 5.7L (1989)
Valve Body: Customer Interest
A/T - Harsh 1 to 2 Shift
Number:
90-237-7A
Section:
7A
Date:
May 1990
Corp. Bulletin No.: 077117
Subject:
HARSH 1-2 SHIFTS - NEW VALVE BODY ASSEMBLY AND REAR ACCUMULATOR SPRING
Model and Year:
1989-90 C, K, R, V, P TRUCK AND G VAN WITH 3L80 (THM 400) AUTOMATIC TRANSMISSION AND 5.7L ENGINE
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 that improve the 1-2 shift feel.
DATE OF PRODUCTION CHANGE: (Figure 1)
Beginning December 21, 1989 (Julian Date 355) all LMA, LWA and SAA 1990 HYDRAMATIC 3L80 (THM 400) transmission models were built with
the new Valve Body Assembly (49) and Rear Accumulator Spring (78).
SERVICE PARTS INFORMATION:
Part Number
Part Name
8675778
Spring - Rear Accumulator (78)
8676823
Valve Assembly - Control (49)
IMPORTANT:
BOTH PARTS MUST BE SERVICED TOGETHER.
SERVICE MANUAL REFERENCE:
Refer to the Unit Repair Section of the appropriate Service Manual for the proper replacement procedures.
Parts are currently available from GMSPO.
