6000 V6-191 3.1L (1989)
Band: All Technical Service Bulletins
A/T - Revised 1-2 Band Assembly
Bulletin Number:
90-7-34
Reference Number:
077110
Publish Date:
4/90
Subject:
NEW 1-2 BAND ASSEMBLY - DOES NOT REQUIRE 1-2 BAND STOP
Models
Affected:
1984-90 6000, BONNEVILLE AND GRAND PRIX MODELS WITH 4T60 (440-T4)
Figure 1 - Previous And New 1-2 Band Assembly
BULLETIN COVERS:
(Figure 1)
A new style 1-2 band assembly will be used in production of all HYDRA-MATIC 4T60 (THM 440-T4) transaxles. The area on the new 1-2 band
assembly where the 1-2 band apply pin engages is almost twice as wide as the previous style. This increased area makes for a larger "target" for the 1-2
band apply pin and eliminates the need for the 1-2 band stop.
The 1-2 band stop was used to keep the 1-2 band assembly from shifting off location. If the band shifts off location, this would cause the 1-2 band apply
pin to miss the band while stroking, creating a loss of drive.
SERVICE PROCEDURE:
The new style 1-2 band assembly can be used to service past model cases, but the 1-2 band stop must be removed.
IMPORTANT:
If the new 1-2 band assembly is used with a 1-2 band stop, durability concerns may result.
DATE OF PRODUCTION CHANGE:
The new 1-2 band assembly went into production starting January 16, 1990 (Julian Date 016).
SERVICE NOTES:
When the supply of previous style 1-2 band assemblies is depleted, the new 1-2 band assembly will be the only style available.
SERVICE PARTS
INFORMATION:
Part Number
Description
Model Year/Model Usage
8668984
Pkg. 1-2 Band Assembly
1984-90
All
-
1-2 Band Assembly
-
Instruction Sheet
Parts are currently available from GMSPO.