LEAK FROM TRANSFER CASE REAR EXTENSION, VIBRATION/NOISE. Chevrolet Astro

SUBJECT: LEAK FROM TRANSFER CASE REAR EXTENSION, VIBRATION/NOISE WHILE DRIVING (REPLACE TRANSFER CASE REAR EXTENSION)

MODELS: 1998 CHEVROLET AND GMC L VAN MODELS EQUIPPED WITH ALL WHEEL DRIVE TRANSFER CASE (RPO NP3)

CONDITION:

SOME OWNERS MAY COMMENT ABOUT A DRIVELINE LEAK OR A VIBRATION/NOISE WHEN THE VEHICLE IS DRIVEN. THE LEAK MAY BE CENTERED AROUND THE TRANSFER CASE REAR EXTENSION OIL SEAL.

CAUSE:

CONDITIONS MAY BE CAUSED FROM AN OVERSIZED BUSHING BORE IN THE TRANSFER CASE REAR EXTENSION. THIS MAY ALLOW THE BUSHING TO "WALK" OUT OF THE EXTENSION. IF THIS BUSHING MOVES, THE BUSHING MAY CUT OR DAMAGE THE REAR EXTENSION SEAL AND CAUSE A FLUID LEAK.

CORRECTION:

INSPECT THE REAR EXTENSION BUSHING FOR SIGNS OF LOOSENESS. VERIFY THAT THE BUSHING HAS NOT MOVED INSIDE OF THE EXTENSION. IF THE BUSHING IS LOOSE OR HAS MOVED, REPLACE THE REAR EXTENSION. ALSO INSPECT THE SEAL. IF THE SEAL SHOWS SIGNS OF DAMAGE, REPLACE THE SEAL. REFER TO THE 1998 UNIT REPAIR MANUAL, VOLUME 2, SECTION 4, BORG WARNER 4472 FOR EXTENSION REPLACEMENT PROCEDURES. USE THE PART NUMBERS LISTED BELOW.

PARTS INFORMATION:

P/N DESCRIPTION QTY --- ----------- --- 12545732 EXTENSION, TRANSFER CASE REAR 1 10117848 SEAL, TRANSFER CASE 1

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION DESCRIPTION LABOR TIME --------- ----------- ---------- K4260 GASKET OR SEAL, TRANSFER USE PUBLISHED CASE REAR OUTPUT SHAFT HOUSING LABOR OPERATION - REPLACE TIME

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.