NEW 1-2 BAND ASSY. DOES NOT REQUIRE 1-2 BAND STOP

Models Affected: 1984-90 6000, BONNEVILLE AND GRAND PRIX MODELS WITH 4T60 (440-T4)

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.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.