CLUTCH SLIPPING/HIGH PEDAL EFFORT. GMC Truck GMC MD Bus Chassis (B Model) 1997

SUBJECT: CLUTCH SLIPPING/HIGH PEDAL EFFORT (INSTALL CLUTCH KIT)

MODELS: 1990-96 CHEVROLET KODIAK AND GMC TOP KICK 1990-97 B7 SERIES SCHOOL BUSSES 1997 CHEVROLET AND GMC C AND T SERIES MEDIUM DUTY TRUCKS WITH MANUAL TRANSMISSION AND 14 INCH CLUTCH

CONDITION:

SOME CUSTOMERS MAY COMMENT ABOUT LESS THAN EXPECTED CLUTCH LIFE AND/OR HIGH PEDAL EFFORT.

CAUSE:

CLUTCH LIFE CAN BE AFFECTED BY MORE FREQUENT THAN EXPECTED CLUTCH USAGE, VEHICLE OVERLOADING, DRIVER SHIFT HABITS OR INCORRECT ADJUSTMENT.

CORRECTION:

REPLACE THE CLUTCH DISC, PRESSURE PLATE AND RELEASE BEARING WITH ONE OF THE SERVICE KITS LISTED BELOW. THESE KITS FEATURE A REVISED CLUTCH DISC FACING THICKNESS OF 10.0 MM COMPARED TO 9.4 MM FOR THE PREVIOUS CLUTCH DISC.

IMPORTANT: THIS NEW THICKER CLUTCH DISC IS NOT COMPATIBLE WITH THE FORMER PRESSURE PLATE. OLD AND NEW PARTS SHOULD NOT BE MIXED. THEREFORE, ALL SERVICE CLUTCHES WILL NOW BE AVAILABLE ONLY AS KITS (CLUTCH DISC, PRESSURE PLATE AND RELEASE BEARING).

AS A RESULT OF THIS CHANGE, TWO FORMER 14" PULL-TYPE CLUTCH KITS, P/N 12542908 AND P/N 12548391, HAVE BEEN CANCELED. THE FORMER (9.4 MM) CLUTCH DISC, P/N 15727269, HAS ALSO BEEN CANCELED AND WILL NO LONGER BE SERVICED. SEE PARTS INFORMATION BELOW.

IMPORTANT: WHEN SERVICING TOP KICK, KODIAK, SCHOOL BUS AND SOME EARLY PRODUCTION 1997 C MODELS WITH THE NEW KITS, THE TECHNICIAN WILL NOTICE THAT A CONSIDERABLE CLUTCH CABLE READJUSTMENT WILL BE REQUIRED. GEOMETRIC DIFFERENCES WITHIN THE CLUTCH COVER RESULT IN A DIFFERENT LEVER POSITION. THE USE OF A DIFFERENT CLUTCH LEVER RETURN SPRING BRACKET, P/N 15740326, IS ALSO REQUIRED ONLY BECAUSE OF THIS NEW LEVER POSITION. SEE PARTS LIST BELOW.

SERVICE PROCEDURE:

FOLLOW THE CLUTCH REPLACEMENT PROCEDURE IN SECTION 7C OF THE APPROPRIATE MEDIUM DUTY SERVICE MANUAL.

ADJUSTMENT:

FIRST SET THE RELEASE BEARING TO CLUTCH FINGER TRAVEL GAP BEFORE ATTEMPTING ANY ADJUSTMENT AT THE CLUTCH CABLE.

PARTS INFORMATION:

FORMER P/N CURRENT P/N DESCRIPTION QTY

12542908 12375613 CLUTCH KIT; 1 3116 DIESEL-200/250 HP. 6H, 7H AND BUS MODELS

12548391 12375614 CLUTCH KIT; 1 3116 DIESEL-275 HP. 6H, 7H AND BUS MODELS

12542908 12375615 CLUTCH KIT, 1 3116 DIESEL-200-250 HP. 1997 T MODELS ONLY

12548391 12375616 CLUTCH KIT, 1 3116 DIESEL-275 HP. 1997 T MODELS ONLY

15727269 NONE CLUTCH DISC; 1 9.4MM THICKNESS 3116 DIESEL-200/275 HP.

15624801 15740326 BRACKET, CLUTCH LEVER RETURN SPRING 1

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE

LABOR OP DESCRIPTION LABOR TIME K0800 DISC AND/OR CLUTCH USE PUBLISHED COVER-REPLACE LABOR OPERATION TIME

IMPORTANT: LABOR OPERATION IS CODED TO BASE VEHICLE COVERAGE IN THE WARRANTY SYSTEM.

FIGURES: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.