Campaign - A/T Noisy, Poor Operation: Overview

GMC NUMBER:
92-C-17

GROUP:
7A Automatic Transmission

DATE:
July 1992

SUBJECT:
4L80-E OR 4L80-EHD AUTOMATIC TRANSMISSION REAR INTERNAL GEAR

MODELS:
1992 C/K, P30 TRUCKS AND G VANS

Note:
The service part information has been corrected for model DNP, TSB # 92C17A, dated 08/92.

General Motors has determined that certain 1992 GMC C/K, P30 Trucks and G Vans equipped with 4L80-E or 4L80-EHD automatic transmissions may have a transmission rear internal gear with an improper heat treat process. With extended use this may cause noisy operation, sluggish forward gear operation, no motion in reverse, and/or no motion in drive.

To correct this condition, dealers are to replace the rear internal gear.