Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
Clutch: Customer Interest
A/T - Premature Wear of Direct Clutch
GMC NUMBER:
90-7A-105
GROUP:
7A Automatic Transmission
DATE:
October, 1990
CORPORATE
NUMBER:
077134
SUBJECT:
DIRECT CLUTCH DISTRESS
MODELS:
1985-90 C/K, R/V, P TRUCKS AND G-VAN WITH 3L80 AND 3L80-HD AUTOMATIC TRANSMISSIONS
BULLETIN COVERS Some HYDRA-MATIC 3L80/3L80-HD models experienced Direct Clutch distress. This distress was caused by an oil leak in the
clutch apply circuit at the Center Support joint between the Case and the Center Support. A new Center Support (654), Case Assembly (10), Piston (650)
and Bolt (79) eliminated this root cause for Direct Clutch distress.
Figure 1
DATE OF PRODUCTION CHANGE (See Figure 1) Beginning March 1, 1990 (Julian Date 060) all 1990 HYDRA-MATIC 3L80/3L80-HD
transmissions were built with the new Center Support (654), Case Assembly (10), Intermediate Piston (650) and Bolt (79).
Figure 2
SERVICE PROCEDURE (See Figure 2)
Important
Use new bolt (79) only with new support (654) and new piston (650). Use new piston (650) only with new support (654). Use new support assembly
(654) in previous case (10) only with previous bolt (79). Use new case (10) only with new support (654), new piston (650) and new bolt (79). Do not
reuse old Center Support (654).
