G 20 Van V6-262 4.3L VIN Z (1993)
Extension Housing: All Technical Service Bulletins
A/T Case Extension - Leaks
Number: 93-185-7A
Section: 7A
Date: MAY 1993
Corporate Bulletin No.: 377122
ASE No.: A2
Subject:
VIBRATION/FLUID LEAK OUT OF CASE EXTENSION (REPLACE CASE EXTENSION ASSEMBLY)
Model and Year:
1993 C, P TRUCKS AND G VANS WITH 4L80-E/4L80-EHD AUTOMATIC TRANSMISSION
Some HYDRA-MATIC 4L80-E/4L80-EHD transmissions may leak fluid at the back of the case extension assembly (19) or a vibration may be noticed
in all ranges at all speeds.
CAUSE:
This is caused by the extension bushing (77) not seated properly due to an oversized bore, possibly interfering with the case extension helixseal assembly
(20).
CORRECTION: (Figure 2)
Inspect the case extension helixseal assembly (20) for any damage and see if the bushing (77) has moved. If the bushing has moved, order a new case
extension assembly (19) which includes the properly installed bushing and install a new helixseal assembly (20).
Do not attempt to repair the extension by staking, sealing, or securing bushing in place