A/T - No Reverse, New Rear Band
GMC NUMBER: 92-7A-98GROUP: 7A Automatic Transmission
DATE: June 1992
CORPORATE
NUMBER: 277125R
SUBJECT:
NO REVERSE (NEW REAR BAND ASSEMBLY)
MODELS:
1991-92 C/K, R/V, G, P TRUCKS WITH 4L80E/4L80EHD
CONDITION:
Some HYDRA-MATIC 4L80-E/4L80-EHD Transmissions may experience a no reverse condition.
CAUSE:
This is caused by the lugs on the rear band assembly not holding to the case pins, causing the reaction drum not to hold.
CORRECTION:
A new Rear Band Assembly was released to eliminate anchor lug fatigue.
DATE OF PRODUCTION:
(Figures 1 & 2)
Starting April 11, 1992 (Julian Date 101) all 4L80-E/4L80-EHD were buift with this new Rear Band Assembly.
SERVICE PART INFORMATION:
8681620 Band Assembly, Rear Brake
Parts are currently available at GMSPO.
SERVICE PROCEDURE:
(Figure 3)
On all 1991 vehicles, the Band Assembly and Case Assembly with added ribs to strengthen the anchor pin area must be serviced together. All 1992 vehicles have the new Case Assembly, only the Band Assembly is serviced. Refer to your appropriate catalog for oorrect case assembly numbers.
The previous Band Assembly (8677313) can be used, until new bands are available, if the band has a blue ink stamp 295 or has an idenfification date stamp.