S15/T15 Jimmy 2WD V6-173 2.8L VIN B 2-bbl (1983)
Torque Converter Clutch: All Technical Service Bulletins
A/T - Torsional Rattle Or Rining Noise
Number:
85-194
Section:
7A
Date:
APR., 1986
Subject:
TORSIONAL RATTLE
Model and Year:
1983-85 S/T TRUCK WITH 2.8L ENGINE AND THM 700-R4 TRANSMISSION
TO:
ALL CHEVROLET DEALERS
Some 1983-85 S/T trucks equipped with the 2.8L V6 engine and THM 700-R4 automatic overdrive transmission may experience a
torsional rattle or ringing type of noise when the torque converter clutch (TCC) engages at light throttle application below 40 mph.
This condition, which is torque converter clutch/drivetrain related, may be improved by increasing the TCC engagement speed. A
TCC throttling valve, service kit P/N 8642970, is available to increase the TCC engagement speed to 40 - 45 mph.
Included in the service kit are:
^
TCC Throttling Valve
^
TCC Throttling Valve Sleeve
^
TCC Throttling Valve Spring
^
Instruction Sheet
FIGURE NO. 1
The installation of the service kit requires removal and partial disassembly of the transmission valve body (Figure No. 1). Follow
the instructions included with the service kit.
If additional dampening of torsional noise is necessary, some improvement may be obtained by filling the propshaft with urethane
foam following the procedure listed below:
1.
Obtain a urethane foam dispensing system, Insta-Foam Product's Model #9.5 Froth Pak Kit (or equivalent) which is a small
volume kit complete with all the required chemicals, dispensing equipment and instructions. A maximum of one (1) Froth
Pak Kit will be required to foam-fill a propshaft from a long wheel vase vehicle such as a Suburban or Pickup.
2.
Remove propshaft from vehicle.
