M/T Clutch - Shudder or Chatter on Launch
90chevy23GMC NUMBER: 90-7C-91
GROUP: 7C CLUTCH
DATE: SEPTEMBER, 1990
CORPORATE
NUMBER: 067302
SUBJECT: CLUTCH CHATTER/SHUDDER ON LAUNCH
MODELS: 1988-90 C/K TRUCKS EQUIPPED WITH 5.7L AND 6.2L ENGINES 4-SPEED AND 5-SPEED MANUAL TRANSMISSIONS
Some 1988-90 C/K trucks equipped with 5.7L and 6.2L engines with 4-speed and 5-speed manual transmissions may experience a condition of chatter or shudder on launch. Revised clutch discs and matching pressure plates have been released for these vehicles and are available through GMSPO. The installation of these parts will provide significant improvement in the involved vehicles.
DATE OF PRODUCTION CHANGE Revised pressure plates were installed shortly after the start of the 1990 model year. Revised clutch discs will be installed at the start of the 1991 model year.
SERVICE PROCEDURE 1988 OR 1989 MODEL: The pressure plate and clutch disc should be replaced at the same time as the parts have been designed to work together
1990 MODEL: These vehicles should require a new clutch disc only. However, when the pressure plate is removed inspect the cover for a manufacturers name stamp. If the name Valeo appears on the pressure plate cover the pressure plate is of the revised design and does not need replacement unless damaged. If the name Borg and Beck
appears on the pressure plate cover the pressure plate assembly requires replacement. Only very early production 1990 vehicles may be equipped with Borg and Beck pressure plates. Refer to section 7C of the appropriate service manual for clutch disc and pressure plate replacement procedure.
SERVICE PARTS INFORMATION
Pressure Clutch
Engine Transmission Plate P/N Disc P/N
5.7L 5 Speed 15638388 15668525
5.7L 4 Speed 15638388 15668526
6.2L 4 Speed 15638388 15668525
Parts are currently available through GMSPO.
WARRANTY INFORMATION For vehicles repaired under warranty use:
Labor Operation: K0800
Labor Time: Use appropriate labor time in the labor time guide.