MOAN NOISE IN TRANSFER CASE (REPLACE TRANSFER CASE FLUID). GMC Truck Yukon

SUBJECT: MOAN NOISE IN TRANSFER CASE (REPLACE TRANSFER CASE FLUID)

MODELS: 1998 CHEVROLET AND GMC K1-2 MODELS WITH NV246 TRANSFER CASE (RPO NP8)

1998 OLDSMOBILE BRAVADA WITH NV136 TRANSFER CASE (RPO NP4)

CONDITION:

SOME OWNERS MAY COMMENT ABOUT A MOAN TYPE NOISE WHEN THE VEHICLE IS OPERATED IN THE AUTO 4WD POSITION AND IS DRIVEN IN DEEP SAND, DEEP SNOW, OR DEEP MUD.

WHEN OPERATING K MODEL VEHICLES IN THE ABOVE CONDITIONS, SELECTING THE 4LO OR THE 4HI POSITION, INSTEAD OF THE AUTO 4WD, MAY HELP TO REDUCE NOISE.

CAUSE:

CONDITION MAY BE CAUSED BY A SLIP-STICK CONDITION IN THE CLUTCH ASSEMBLY.

CORRECTION:

DRAIN THE TRANSFER CASE FLUID. ADD REVISED TRANSFER CASE FLUID USING THE PART NUMBER LISTED BELOW. REFER TO THE SERVICE PROCEDURE IN SECTION 4-TRANSFER CASE OF THE APPROPRIATE SERVICE MANUAL. REFER TO CORPORATE BULLETIN NUMBER 76-74-03, DATED APRIL,1998, FOR INFORMATION ON REMOVING THE TRANSFER CASE DRAIN AND FILL PLUGS.

PARTS INFORMATION:

P/N DESCRIPTION QTY 12378396 TRANSFER CASE FLUID 2

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

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