Custom Cruiser V8-307 5.0L (1987)
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,