C 1500 Truck 2WD V6-262 4.3L VIN Z (1992)
SERVICE INFORMATION: (Figure 2)
A new center support bolt has been released for service to allow the center support to be reconditioned one time for all HYDRA-MATIC
4LBO-E/4L8O-EHD and for all 3L80/3L80-HD transmissions built March 1, 1989 (Julian Date 060) and later. Refer to 3L80/3L80-HD corporate
bulletin # 077134 (Chevrolet 90-357-7A; GMC Truck 90-7A-105; GM of Canada 9073L80104) concerning changes to the case and center support bolt.
Beginning on December 21, 1993 (Julian Date 355), some 4L8O-E/4L80-EHD AND 3L80/3L8O-HD SRTAS (Service Replacement Transmission
Assembly) are being built with the new service bolt. The new service bolt is coated with zinc chromate and is yellow In color. The current production
bolt is phosphate coated and is black in color. The current production bolt and the service bolt are the same length.
When servicing a 4L80-E/4L80-EHD or a 3LBO/3LBOHD built after March 1, 1990, the center support can be reconditioned one time using J 39919,
Center Support Reamer and Gauge and the service bolt package. IF THE TRANSMISSION ASSEMBLY CONTAINS THE SERVICE BOLT OR IF
THE 3L80/3LBO-HD CONTAINS THE SHORT PRODUCTION CENTER SUPPORT BOLT, THE CENTER SUPPORT AND BOLT MUST BE
REPLACED. (Refer to corporate bulletin #077143.)
PARTS INFORMATION:
GMC truck dealers should refer to corporate bulletin #367106. Automatic Transmission Service Procedure Changes, published in December, 1993 for
correct service procedures for repairs under warranty.
Parts are currently available from GMSPO.
INSTRUCTIONS:
This bolt allows one time reuse/reassembly of the center support by achieving the same level of thread interference as the production assembly. The
service bolt has a zinc chromate (yellow/gold) plating to aid in identification. The current production bolt is the same length as the service bolt and has a
black phosphate (black color) coating.
Note:
Kent-Moore service tool J 39919 must be used to resize the thread In the center support before reassembly to the transmission case. See Kent Moore
Instruction sheet for proper use of tool.
