REAR CRANKSHAFT OIL SEAL LEAK (REPLACE REAR MAIN OIL SEAL)

SUBJECT: REAR CRANKSHAFT OIL SEAL LEAK (REPLACE REAR MAIN OIL SEAL)

MODELS: 1992-94 W4 CHEVROLET TILTMASTER 1992-94 W4 GMC FORWARD MODELS WITH 4BD2-TC DIESEL ENGINE (VIN K)

CONDITION:

A CUSTOMER MAY COMMENT ON AN OIL LEAK FROM THE REAR OF THE ENGINE.

CORRECTION:

VERIFY THE SOURCE OF THE LEAK. IF THE REAR CRANKSHAFT OIL SEAL IS THE CAUSE, REPLACE IT WITH REDESIGNED SEAL, P/N 97072823.

SERVICE PROCEDURE:

1. REMOVE THE FLYWHEEL, AS DESCRIBED IN THE APPROPRIATE WORKSHOP MANUAL.

IMPORTANT: W4 TRUCKS EQUIPPED WITH AUTOMATIC TRANSMISSIONS HAVE A PILOT SLEEVE (PILOT BUSHING) FITTED INTO THE END OF THE CRANKSHAFT (FIGURE 1, ITEM 3). THIS PILOT SLEEVE MUST BE REMOVED BEFORE INSTALLING THE NEW REAR CRANKSHAFT OIL SEAL.

2. REMOVE THE EXISTING REAR CRANKSHAFT OIL SEAL FROM THE RETAINER, USING SPECIAL TOOL J-41268 REAR WEAR SLEEVE REMOVER (FIGURE 2, ITEM 3).

3. INSTALL THE NEW REAR CRANKSHAFT OIL SEAL AS FOLLOWS.

NOTICE: DO NOT APPLY FORCE TO THE AREA BETWEEN THE REAR CRANKSHAFT OIL SEAL AND THE OIL SLINGER. DAMAGE TO THE REAR CRANKSHAFT OIL SEAL WILL RESULT.

A. MOUNT THE ADAPTER FOR THE SPECIAL TOOL J-41269 REAR MAIN OIL SEAL INSTALLER, ONTO THE REAR OF THE CRANKSHAFT USING TWO OF THE SIX FLYWHEEL RETAINING BOLTS (FIGURE 3, ITEM 2) REMOVED IN STEP 1.

B. PLACE THE NEW REAR CRANKSHAFT OIL SEAL OVER THE OUTER CIRCUMFERENCE OF THE SPECIAL TOOL ADAPTER.

C. INSERT SPECIAL TOOL J-41269 INTO ITS ADAPTER AND TIGHTEN THE BOLT UNTIL THE ADAPTER CONTACTS THE SLEEVE.

D. REMOVE THE SPECIAL TOOL AND ADAPTER.

4. AFTER THE NEW REAR CRANKSHAFT OIL SEAL IS INSTALLED, MEASURE THE OIL SEAL GAP (FIGURE 4). ENSURE THAT THE OIL SEAL GAP MEASUREMENT IS 0.44 TO 0.47 INCH (11.3 TO 11.9MM).

IMPORTANT: IF THE OIL SEAL GAP MEASUREMENT IS INSUFFICIENT, THE SEAL MUST BE SEATED FURTHER ONTO THE CRANKSHAFT. IF THE GAP MEASUREMENT IS EXCESSIVE, THE INSTALLED OIL SEAL MUST BE REMOVED AND REPLACED WITH A NEW OIL SEAL.

5. REINSTALL THE FLYWHEEL AND PILOT SLEEVE IF APPLICABLE, AS DESCRIBED IN THE APPROPRIATE WORKSHOP MANUAL.

PART INFORMATION:

P/N DESCRIPTION QTY 97072823 SEAL, OIL CRANKSHAFT, REAR 1

PARTS WILL BE AVAILABLE ON JULY 1, 1996 FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION DESCRIPTION LABOR TIME J1120 R+R REAR CRANKSHAFT USE PUBLISHED LABOR OIL SEAL OPERATION TIME

IMPORTANT: LABOR OPERATION IS CODED TO BASE VEHICLE COVERAGE IN THE WARRANTY SYSTEM. THIS INC: R+R TRANSMISSION AND FLYWHEEL.

FIGURES: 4

CAPTIONS: 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.

COPYRIGHT 1996 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.