SMU-SECTION 3C-FRONT SUSPEN AND AXLE -INCORRECT U-BOLT. GMC Truck GMC MD Conventional (C Model) 1996

SUBJECT: SERVICE MANUAL UPDATE - SECTION 3C - FRONT SUSPENSION AND AXLE - INCORRECT U BOLT NUT TORQUE

MODELS: 1994-96 CHEVROLET AND GMC MEDIUM DUTY TRUCKS

THIS BULLETIN IS BEING ISSUED TO REVISE SECTION 3C - FRONT SUSPENSION AND AXLE. PLEASE REPLACE CURRENT INFORMATION WITH THAT GIVEN IN THIS BULLETIN.

FRONT AXLES- *FRONT AXLE U-BOLT TORQUE CHANGED FOR SOME VEHICLES OF THE 1994 MODEL YEAR MEDIUM DUTY TRUCKS. VEHICLES BEGINNING WITH THE VIN OF 1GDE6H1J6SJ506385 USE ONLY 20MM U-BOLTS AND U-BOLT NUTS FOR THE FRONT AXLE REGARDLESS OF THE AXLE APPLICATION. PRIOR TO THIS VIN, 16MM AND 20MM U-BOLTS AND U-BOLT NUTS WERE USED. FROM THIS VIN ON ONLY 20 MM U-BOLTS AND U-BOLT NUTS WERE USED. THEREFORE, THE STATEMENT OF: TIGHTEN ALL FRONT AXLE U-BOLT NUTS ON VEHICLES BEGINNING WITH THE VIN 1GDE6H1J6SJ506385 TO 325-350 NM (258 LB. FT.) REGARDLESS OF AXLE I IDENTIFICATION MUST BE ADDED TO THE FOLLOWING SERVICE MANUAL PAGES FOR *ALL 1995-96 MODEL YEAR MEDIUM DUTY TRUCKS, USE ONLY 20MM U-BOLTS AND U-BOLT NUTS. THE SERVICE MANUAL CURRENTLY STATES THAT THERE ARE DIFFERENT TORQUE RATINGS DEPENDING ON THE AXLE USED. THIS INFORMATION IS INCORRECT. THERE IS ONLY ONE TORQUE FOR THE U-BOLTS AND U-BOLT NUT FOR THESE MODEL YEARS, THAT TORQUE IS 325-350 NM (258 LB.FT.) PLEASE REPLACE THE OLD TORQUE VALUES FOUND IN THE 1995 AND 1996 MODEL YEARS SERVICE MANUALS ON THE FOLLOWING PAGES: *1995 --PAGES 3C-14 AND 3C-20. *1996 --PAGES 3C-13 AND 3C-19.

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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.