A/T - Delayed Park or Neutral to Drive Shift Engagement
89Oldsmobile01SUBJECT: DELAYED PARK/NEUTRAL TO DRIVE SHIFT ENGAGEMENT - NEW FORWARD CLUTCH HOUSING ASSEMBLY
MODELS/YEARS: 1981-87 CUTLASS SUPREME, 1988 CUTLASS
SUPREME CLASSIC, 1981-85 EIGHTY-EIGHT, 1981-89 CUSTOM CRUISER, 1981-84 NINETY-EIGHT MODELS EQUIPPED WITH THM 2004R (MW9) TRANSMISSION
NUMBER: 89-T-46
CORP. REF. NO: 977102R
DATE: February 1989
SECTION: 7A
BULLETIN COVERS:
Service and parts information for a new forward clutch housing and shaft assembly. The new assembly has a larger forward clutch feed orifice in the forward clutch shaft. The new forward clutch housing and shaft assembly may address a delayed drive engagement concern (refer to "Service Action"). There are no changes to the forward clutch die cast piston and clutch pack that were introduced with the neutral to drive (feed-bleed) garage shift package (refer to Dealer Technical Bulletin 87-T-27).
FIGURE 1 - THM 200-4R TRANSMISSION IDENTIFICATION INFORMATION:
DATE OF PRODUCTION CHANGE: (Figure 1)
August 24, 1988, Julian Date 237, the now forward clutch housing assembly introduced on all 1989 THM 200-4R models.
FIGURE 2:
FIGURE 3:
SERVICE ACTION:
The THM 200-4R "garage shift package" (refer to Figures 2 and 3) softens the Park/Neutral to Drive shift engagement feel by cushioning the apply of the forward clutch piston. The cushioned apply increases shift time, this does not indicate a transmission durability concern.
When diagnosing a delayed drive engagement concern, verify the apply time using a stopwatch and use the following guidelines to decide if service action is necessary:
1.5 - 2.0 second apply time Normal apply time. The new housing assembly may not provide
a decrease in apply time.
2.0 - 3.0 second apply time The new housing assembly may decrease apply time by approximately .5 - 1.0 second.
3.0 or more second apply time Inspect for other causes* of delayed Drive engagement. If no
other causes are found, the new housing assembly will decrease apply time.
* Conditions which contribute to delayed Drive engagement:
- Improper Fluid Level
- Cut Or Overlapping Teflon Seal Rings On Forward Clutch Shaft
- Cracked Or Broken Forward Clutch Piston
- Cut Or Rolled Forward Clutch Piston Seals
- Porosity In The Center Support
If forward clutch housing replacement is necessary, use the chart under "Service Parts Information" for the appropriate service part number based on model year, build date and transmission model.
SERVICE PARTS INFORMATION:
Part No. Description Year Models
8639969 New Forward Clutch 1986 (built after Julian Date
Housing Assembly 115)
6AAF, 6ABF, 6APF, 6CAF, 6HFF, 6KCF, 6KJF
1987 7CTF, 7HFF, 7KCF, 6KJF,
7HDF
1988 8CTF, 8KTF
1989 All
8639969 should be used to service the above models/years built with the "Garage Shift" package. All other models use part number 8639942 until current GMSPO stock is depleted.
8639970 New Neutral to Drive 1981-82 All Models
Shift Package - 1983 All (Except 3OZ Model)
1984 4AA, 4AP, 4BQ, 4BY,
Contains: New Forward 4HE, 4OG, 4OJ, 4OM
Clutch Housing Complete, 1985 5AA, SAO, 5AP, 5BQ,
Front Internal Gear, and 5HE, 5OG, 5OJ, 5OM
Thrust Washer. 1986 6BRF
(or the following models built before Julian Date 115) 6AAF, 6ABF, 6APF, 6CAF, 6HFF, 6KCF, 6KJF
1987 7BRF
8639970 must be used when updating the above models/years to a Garage Shift package; should that option be desired. All other models being updated to a Garage Shift package, use pad number 8639943 until current GMSPO stock is depleted.
Parts are currently available from GMSPO.