Service Procedure:

Order service parts from the "Service Parts Information" section of this bulletin. Also, check and/or correct the items listed below:

- Other conditions known to cause 4th clutch distress also include: damaged 3-4 accumulator piston seal, loose channel plate torx head bolt (72), leaking driven sprocket, 4th clutch piston seals or missing # 1 check ball from a previous repair or leaking # 5 check ball.
NOTICE: When repair of a distressed 4th clutch has been completed, it is essential to inspect and set the shift cable according to the procedures as outlined in the transaxle on-vehicle service section of the appropriate service manual. To ensure proper cable set, place the driver lever (shift lever inside the passenger compartment) against the reverse side of the neutral gate in the column or console prior to setting the cable at the transaxle.

SERVICE NOTES:

The manual valve link (401) and rod end retaining spring (manual valve) (402) have not been revised for this change.

SERVICE PARTS INFORMATION:

IMPORTANT: If the previous channel plate assembly is ordered for a 1985-1/2 through 1990 model, the order will be superseded to a new service channel plate assembly package that will service the transaxle model. A 1985-1/2 through early 1986 models will require the slot for the inside detent lever to assemble the manual valve link. Order package 8668991 that will contain a new manual valve link that will assemble to the new inside detent lever.

The new service channel plate assembly packages will contain:

- Channel plate assembly
- Valve, manual
- Lever, inside detent

Part Model
Number Description Year Model Usage

8668993 Channel Plate Asm.-Complete 1989-90 AAH, ACH, ABH, ADH
AFH, AHH, AJH, ANH
ATH

8668994 Channel Plate Asm.-Complete 1989-90 LMH, LNH, CLH, CPH
CZH, YPH, YCH, YJH

8668996 Channel Plate Asm.-Complete 1989-90 CHH, YKH, CJH, YLH
CDH CYH, YAH, YFH

8668997 Channel Plate Asm.-Complete 1990 LAH

*8668995 Channel Plate Asm.-Complete 1989-90 BAH, WBII, BDH, WCH
BFII, WLH, BHH, XIRH
BJH, WZH, BPH, WTH
BWH, WUH, PAH, PBH
VXH, VYH
*IMPORTANT: Also, order and install with package 8668995 one of
the two packages listed below for the following 1990 models OBAH, OBDH, OBFH, OBHH, OBPH, OBWH and OBJH with two plate 4th clutch assemblies built from July 10, 1989 (Julian Date 191) to July 31, 1989 (Julian Date 212) of the 1990 Model Year.

Part Model
Number Description Year Model Usage

8668980 Package - Single Plate 4th Clutch 1990 OBAH, OBDH,
- Plate Assembly, 4th Clutch OBFH
- Plate, 4th Clutch Apply
- Plate, 4th Cl. Reaction (2 in Pkg.)
- Bushing/Valve 1-2 Accumulator
- Instruction Sheet

8668981 Package - Single Plate 4th Clutch 1990 OBHH, OBPH,
- Plate Assembly, 4th Clutch OBWH, OBJH
- Plate, 4th Clutch Apply
- Plate, 4th Cl. Reaction (2 in Pkg.)
- Bushing/Valve 1-2 Accumulator
- Instruction Sheet

8668991 Pkg. Lever - Inside Detent 1985-90 All Models
(for new channel plate) Except
Grand Prix with New Service or Production Channel Plate

8668992 Pkg. Lever - Inside Detent 1985-90 Grand Prix
(for new channel plate) Only That
Has New Service or Production Channel Plate

8646958 Pkg. Lever - Inside Detent 1985-90 All Models
(for previous channel plate) Except
Grand Prix with Previous Channel
Parts are currently available for part numbers 8668980, 8668981 and 8646958.

All other parts are expected to be available on 2-16-90. Until then, normal part orders will not be accepted bv GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place.