4T60/440T4/F-7 CODES FOR NEW CHANNEL PLATE & INPUT HOUSING

MODELS AFFECTED: 1990 DE VILLES, FLEETWOODS, ELDORADOS, SEVILLES, AND ALLANTES

New model codes have been established for transaxle units built on or after January 16, 1990 (Julian Date 016). Refer to Figure 1. These units have a new channel plate assembly that does not have an input accumulator. Instead, a wave plate and four steel input clutch plates are used.

IMPORTANT: The shift speed charts, minimum and maximum oil pressure, and wiring diagrams can be found for these new models by using the cross-reference chart in Figure 1. Identify the previous 1990 model code and refer to that information listed in the Service Information Manual when servicing the new 1990 model. For example, the 1990 model OAAH information will apply to the 1990 OKCH model data.

To accommodate the channel plate change, the following parts were modified to eliminate the input accumulator components:

Input Clutch Plate and Wave Plate (Refer to Figure 2)

Four input clutch (steel or reaction) plates (647) are used instead of three. The new input clutch plate will assemble between the added wave plate (810) and input clutch (fiber) plate assembly. The new input clutch plates will also be thinner by .722mm [.028"] to make room for the added wave plate and input clutch plate.) The previous input clutch plates will still be available. Do not mix the previous and new input clutch plates; this will cause a durability concern.

Channel Plate (Refer to Figure 3)

The channel plate (404) will not have an input clutch accumulator bore and components. The wave plate that was added to the input clutch assembly will replace the function of the accumulator. The previous channel plate with the input accumulator bore and components and the new channel plate are not interchangeable. The channel plate with the input accumulator will still be available for past model service.

Manual Valve (Refer to Figure 4)

The new manual valve (403) was reduced .25mm (.010") in diameter to accommodate porting changes in the channel plate. The previous and new manual valves are not interchangeable. The new manual valve will assemble into the previous production channel plate, but the transaxle will not function.

Detent Level (Refer to Figure 5)

The new inside detent lever (704) manual link hole location was changed. The previous and new inside detent lever are not interchangeable even through the parts will assemble. The new inside detent lever must be used with the new manual valve and channel plate. The previous inside detent lever must be used with the previous manual valve and channel plate.

Input Housing (Refer to Fieure 6)

The input housing (632) has been revised by moving the snap ring groove 1.50mm (.059") to allow for the wave plate and extra input clutch plate used in the input clutch. The previous and new input housings are not interchangeable because of the differences in clutch pack free play and travel. The previous input housing will still be available for past model service.

Service Parts Information

SRTA models built as of February 1, 1990 with the new 1990 model codes have all updated parts.

The channel plate assembly packages will contain:

Channel plate assembly without input clutch accumulator bore

Valve, manual

Model P/N Description Year Model Usage

8677250 Channel Plate Assembly-Complete 1990 KCH, KDH, KHH, KLH, KPH, KRH 8651903 Package-Input Clutch Housing 1990 KCH, KDH, KHH, KLH, KPH, KRH 8675257 Plate-Wave 1990 KCH, KDH, KHH, KLH, KPH, KRH 8651446 Plate-Input Clutch 1990 KCH, KDH, KHH, KLH, KPH, KRH 8668991 Package Lever-Inside Detent 1985-1990 All models (for new channel plate)

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.