AUTOMATIC TRANSMISSION CASE CRACKED. GMC Truck GMC MD Steel Tilt 67.9" 1993

SUBJECT: AUTOMATIC TRANSMISSION CASE CRACKED (REPLACE PARKING BRAKE DRUM)

MODELS: 1993-95 CHEVROLET TILTMASTER AND GMC FORWARD W4 MODELS WITH 4L80-E AUTOMATIC TRANSMISSION

CONDITION:

AN OWNER MAY REPORT THE AUTOMATIC TRANSMISSION CASE IS CRACKED IN THE BELLHOUSING AREA.

CAUSE:

THE DRIVELINE IS OUT OF BALANCE.

CORRECTION:

IN THE COURSE OF REPAIRING OR REPLACING THE TRANSMISSION, REPLACE THE ORIGINAL PARKING BRAKE DRUM WITH P/N 97126144 AND REBALANCE THE PROPELLER SHAFT(S) AND PARKING BRAKE DRUM AS AN ASSEMBLY AT A LOCAL DRIVESHAFT REPAIR SHOP PRIOR TO INSTALLING IN THE VEHICLE. THIS PARKING BRAKE DRUM IS MADE OF STAMPED STEEL AND HAS SHOWN TO BE EFFECTIVE IN REDUCING DRIVELINE VIBRATION.

SERVICE PARTS INFORMATION:

P/N DESCRIPTION QTY 97126144 DRUM AND YOKE ASSY. 1 PARKING BRAKE

PARTS ARE CURRENTLY AVAILABLE THROUGH GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OP DESCRIPTION LABOR TIME K7000 TRANSMISSION ASSEMBLY USE PUBLISHED REPLACE LABOR OPERATION TIME 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.