A/T - 3RD Clutch/Overhaul Kits Require Calibration Kits
89chevy34Number: 90-99-7A
Section: 7A
Date: November 1989
Corporate Builetin No.: 977153
Subject: 3RD CLUTCH AND OVERHAUL KITS MAY REQUIRE CALIBRATION UPDATE KITS
Model aN Year: 1989 A CAR AND 1990 W CAR WITH 4T60/440T4 AUTOMATIC TRANSMISSION
Figure 1 - Transaxle Identification:
Figure 2 - Valve Body:
Figure 3 - Servo Cushion Spring:
Figure 4 - 1-2 Accumulator Spring:
TO: ALL CHEVROLET DEALERS
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 (1 16) (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: