3RD CLUTCH & OVERHAUL KITS MAY REQUIRE CALIBRATION UPDATE KIT

Model and Year: 1989 A CAR AND 1990 W CAR WITH 4T60/440T4 AUTOMATIC TRANSMISSION

The bulletin covers new calibration update kit packages that contain calibration update items required when the overhaul and 3rd clutch plate assembly packages are no longer available for early 1989 HYDRA-MATIC 4T60 models built before March 17, 1989 (Julian Date 076) (this includes early 1990 W car models OCHH and OCJH). When the supply of the previous 3rd clutch plate assemblies (both 3rd clutch plate and overhaul packages) is depleted, the new style 3rd clutch plates must be used with the calibration update kit packages listed under "Service Parts Information." (See Figures 1 - 4.)

1) Check Julian Date of transaxle:

A) If built on or after Julian Date (076), use 8662990 for 3rd clutch plates and 8662989 for overhaul packages. Complete repairs; no further steps required.

B) If built before Julian Date (076) and the I.D. tag has the previous model codes shown in figure 1, order 8662954 for 3rd clutch plates and 8662960 for overhaul packages. If these packages are not available, then order the package listed in 1A and the calibration update kit package listed under "Service Parts Information" for the transaxle model. Go to step 2.

2) Update the valve body assembly and replace the following:

- 2-3 accumulator valve spring (336) (most models) (Figure 2) - 3-2 control valve spring (341) (all models) (Figure 2) - Spacer plate assembly (031) (some models) (not shown) - 1-2 servo cushion spring (559) (all models) (Figure 3) - 1-2 accumulator valve spring (326) (CPH model only) (Figure 2) - 1-2 accumulator spring (116) (CPH model only) (Figure 4)

IMPORTANT: All components supplied in the calibration update kit package must be installed to complete calibration update. If not, this will cause a slip-bump condition on 2-3 and 3-2 shifts.

3) Once all calibration update components have been installed, apply new adhesive models tag supplied. Refer to Figure 1 for proper location and correct tag to apply. This will indicate that the transaxle has been updated to latest build level.

SERVICE PARTS INFORMATION:

IMPORTANT: The 1989 calibration update kit package must be used with 8662990 for 3rd clutch plates and 8662989 for overhaul packages.

Model Part Number Description Year Models ----------- ----------- ---- ------ 8675936 Pkg. - 1989 Calibration 1989 9AAH,9ABH,9AFH Update Kit 8675937 Pkg. - 1989 Calibration 1989 9BAH,9BDH Update Kit

8675938 Pkg. - 1989 Calibration 1989 9BFH, 9BMH Update Kit

8675939 Pkg. - 1989 Calibration 1989 9BHH Update Kit

8675940 Pkg. - 1989 Calibration 1989 9BJH Update Kit

8675941 Pkg. - 1989 Calibration 1989 9BPH Update Kit

8675942 Pkg. - 1989 Calibration 1989 9BWH, 9VXH Update Kit

8675943 Pkg. - 1989 Calibration 1989 9CDH,9CLH,9CZH Update Kit

8675945 Pkg. - 1989 Calibration 1989 9PAH Update Kit

8675946 Pkg. - 1989 Calibration 1989 9CPH,9CYH Update Kit

8675947 Pkg. - 1989 Calibration 1989/90 OCHH Update Kit

*8662992 Pkg. - Reverse Shudder/ 1989/90 OCHH 3-2 Flare

**8675948 Pkg. - 1989 Calibration 1989/90 OCJH Update Kit

**8662993 Pkg. - Reverse Shudder/ 1989/90 OCJH 3-2 Flare

* Use Both Packages for OCHH Model ** Use Both Packages for OCJH Model

Parts are currently available from GMSPO.

Refer to the appropriate Service Information Manual for service procedures.

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.