INFO. - USE OF HEAT FOR DIFFICULT TO REMOVE. GMC Truck Yukon

SUBJECT: INFORMATION - USE OF HEAT FOR DIFFICULT TO REMOVE TRANSFER CASE FILL AND DRAIN PLUGS

MODELS: 1998 CHEVROLET AND GMC K1-2 SUBURBAN, UTILITY MODELS WITH NV246 TRANSFER CASE (RPO NP8) 1998 OLDSMOBILE BRAVADA WITH NV136 TRANSFER CASE (RPO NP4)

SOME TRANSFER CASE FILL AND DRAIN PLUGS MAY BE DIFFICULT TO REMOVE. IN SOME CASES, THE PLUG MAY BE "ROUNDED OUT" ATTEMPTING TO REMOVE IT. THESE PLUGS ARE MADE OF ALUMINUM AND HAVE A 1/4 INCH SQUARE HOLE DESIGNED TO RECEIVE A 1/4 INCH DRIVE SOCKET WRENCH. INSTALLATION TORQUE MAY HAVE BEEN TOO HIGH CAUSING DIFFICULTY IN REMOVAL.

IN CASES WHERE THE PLUGS CANNOT BE LOOSENED, THE USE OF AN ELECTRIC HEAT GUN MAY MAKE PLUG REMOVAL POSSIBLE. HEAT SHOULD BE APPLIED TO THE CASE AROUND THE PLUG, NOT DIRECTLY ON THE PLUG,FOR ONE TO TWO MINUTES. USE ONLY ENOUGH HEAT TO LOOSEN THE PLUG. ALSO, MAKE SURE THAT THE 1/4 INCH DRIVE SOCKET WRENCH IS FULLY INSERTED INTO THE PLUG BEFORE TURNING THE PLUG.

CAUTION:

TO HELP AVOID A FIRE, THOROUGHLY CLEAN THE AREA AROUND THE FILL AND DRAIN PLUGS OF OIL OR GREASE BUILD-UP BEFORE HEATING AND USE ONLY AN ELECTRIC HEAT GUN. DO NOT USE AN OPEN FLAME. IF SOURCES OTHER THAN AN ELECTRIC HEAT GUN ARE USED, THE TRANSFER CASE MAY CATCH FIRE.

IF THE FILL OR DRAIN PLUGS ARE DAMAGED DURING REMOVAL AND MUST BE REPLACED, USE ONLY ALUMINUM REPLACEMENT PLUGS WHICH ARE AVAILABLE THROUGH GMSPO. DO NOT USE PLUGS MADE OF STEEL OR BRASS AS THEY WILL CAUSE A SEVERE CORROSIVE REACTION WHEN IN CONTACT WITH THE MAGNESIUM CASE, MAKING FUTURE REMOVAL EVEN MORE DIFFICULT.

FILL AND DRAIN PLUG INSTALLATION TORQUE IS 20 N.M (15 LB FT).

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION DESCRIPTION LABOR TIME K4290 PLUG, TRANSFER CASE DRAIN 0.5 HR - REPLACE

FIGURES: 00 ATTACHMENTS: 00

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.