RIGHT DRIVE AXLE SEAL LEAK DUE TO DIFFERENTIAL

SOME 1980 SKYLARKS AND EARLY PRODUCTION 1981 SKYLARKS WITH THM 125 TRANSMISSIONS HAVE A CONDITION OF PREMATURE WEAR OF THE FINAL DRIVE DIFFERENTIAL CARRIER. THIS CAN RESULT IN A TRANSMISSION OIL LEAK AT THE RIGHT DRIVE AXLE SEAL.

A SPECIAL POLICY ON SUBJECT VEHICLES CONCERNING THIS LEAK CONDITION IS COVERED IN DEALER INFORMATION BULLETIN 81-1-161, GROUP POLICY, DATED APRIL, 1982. THIS BULLETIN PROVIDES DIAGNOSIS INFORMATION AND THE RECOMMENDED REPAIR PROCEDURES FOR CORRECTION OF THE RIGHT DRIVE AXLE SEAL LEAK.

SERVICE PROCEDURE

PART I-DIAGNOSIS OF LEAK

1. INSPECT TRANSMISSION IN AREA OF RIGHT DRIVE AXLE SEAL.

2. IF AXLE SEAL IS LEAKING, PORTIONS OF THE TRANSMISSION CASE FROM THE SEAL TO THE OIL PAN RAIL WILL BE WET "TO THE FEEL" WITH RED TRANSMISSION OIL. OIL STAINS ON THE CASE ARE NOT SIGNS OF A CURRENT LEAK, BUT INDICATION OF A PREVIOUS LEAK.

IF WET TRANSMISSION OIL IS EVIDENT, BE SURE SOURCE IS NOT FROM SOME OTHER AREA, SUCH AS SPEEDOMETER DRIVEN GEAR SLEEVE "O" RING.

PROCEED WITH PART II OF THIS PROCEDURE ONLY IF RIGHT AXLE SEAL IS LEAKING

PART II-INSPECTION OF DIFFERENTIAL CARRIER BORE

THIS INSPECTION IS TO DETERMINE IF ONLY DRIVE AXLE SEAL SHOULD BE REPLACED, OR IF BOTH SEAL AND CARRIER AND SIDE GEARS SHOULD BE REPLACED:

1. RAISE THE CAR ON A HOIST THAT DOES NOT USE THE FRONT WHEELS OR CONTROL ARMS FOR SUPPORT (FRAME HOIST, ETC.). LEAVE THE STEERING WHEEL UN- LOCKED SO FRONT WHEELS CAN BE TURNED.

2. REMOVE RIGHT FRONT WHEEL AND TIRE ASSEMBLY.

3. REMOVE SPLASH SHIELD AND RETAINING SCREWS FOR BOTH BRAKE LINE AND HOSE BRACKETS AT CROSSMEMBER SIDE RAIL. REFER TO FIGURE 1.

4. INSTALL TOOL J-28712 AXLE BOOT SEAL PROTECTORS AS SHOWN IN FIGURE 2.

5. REMOVE THE BALL JOINT RETAINING BOLT AND NUT. DO NOT REUSE BOLT. REFER TO FIGURE 3.

6. INSERT A PRY BAR BETWEEN ENGINE CRADLE SIDE MEMBER AND THE RIGHT LOWER CONTROL BAR. PRY DOWNWARD UNTIL THE HUB AND BEARING ASSEMBLY ARE DIS- ENGAGED FROM THE BALL JOINT STUD. REFER TO FIGURE 4.

7. USING TOOL J-28468 AXLE SHAFT REMOVER, DISENGAGE THE AXLE FROM THE TRANSMISSION. REFER TO FIGURE 2.

8. MOVE THE FRONT WHEELS TO A FULL LEFT TURN POSITION.

9. PUSH THE HUB AND BEARING ASSEMBLY TO THE REAR OF THE WHEEL WELL AND PULL THE DRIVE AXLE OUT OF THE TRANSMISSION, SWING THE END PAST THE ENGINE CRADLE SIDE MEMBER UNTIL IT IS FREE TO HANG DOWN FROM THE WHEEL HUB. REFER TO FIGURE 5.

10. REMOVE THE RIGHT AXLE OIL SEAL FROM THE TRANSMISSION CASE, BEING CARE- FUL NOT TO DAMAGE THE TRANSMISSION CASE BORE.

11. INSPECT DIFFERENTIAL CARRIER AXLE SHAFT BORE FOR STEP WEAR. REFER TO FIGURE 6.

A. IF THERE IS A SLIGHT EVEN STEP 360 DEG AROUND BORE, REPLACE ONLY AXLE SHAFT SEAL, PART NUMBER 8631156. PART III OF THIS PROCEDURE.

B. IF THERE IS A LARGER STEP IN BORE IN THE DIRECTION OF THE DIF- FERENTIAL PIN AS SHOWN IN FIGURE 6, A NEW CARRIER AND SIDE GEAR PACKAGE SHOULD BE INSTALLED IN TRANSMISSION. PART NUMBERS ARE AS FOLLOWS:

PART NAME PART NUMBER DIFFERENTIAL CARRIER W/PINIONS 8637972 2.53 AND 2.84 RATIO

DIFFERENTIAL GEAR KIT 8637919

ALSO, REPLACE THE RIGHT HAND DRIVE AXLE SEAL, PART NUMBER 8631156 AND TRANSMISSION OIL STRAINER, PART NUMBER 8631951. FOLLOW THE PROCEDURES OUTLINED IN SECTION 7A-22 OF THE APPLICABLE SKYLARK SERVICE MANUAL FOR REPLACEMENT OF DIFFERENTIAL CARRIER.

AFTER DIFFERENTIAL CARRIER AND SIDE GEARS ARE REPLACED AND TRANSMISSION IS REINSTALLED ON VEHICLE, REINSTALL THE RIGHT DRIVE AXLE FOLLOWING PART III OF THIS PROCEDURE.

PART III - INSTALLATION OF RIGHT DRIVE AXLE SHAFT OIL SEAL AND AXLE.

1. CLEAN SEAL BORE AND INSTALL NEW AXLE OIL SEAL USING J-26938. REFER TO FIGURE 7. BE CAREFUL NOT TO DAMAGE SEAL DURING INSTALLATION.

2. APPLY LUBE TO DRIVE AXLE SEAL AND INSTALL DRIVE AXLE IN TRANSMISSION. USE EXTREME CARE TO PREVENT AXLE SHAFT FROM DAMAGING SEAL DURING INSTALLATION.

3. WITH FRONT WHEELS STRAIGHT AHEAD, INSTALL THE BALLJOINT STUD TO THE HUB AND WHEEL BEARING ASSEMBLY. INSTALL A NEW BALL JOINT RETAINING BOLT, P/N 14002157, AND NUT AND TORQUE TO 50NM (40 FT. LBS.) REFER TO FIGURE 3.

4. REMOVE TOOL J-28712 AXLE SHAFT BOOT SEAL PROTECTORS.

5. INSTALL THE RIGHT SIDE FRONT BRAKE PIPE AND HOSE BRACKETS AND SPLASH SHIELD.

6. LOWER THE CAR.

7. IF OIL PAN WAS REMOVED, FILL TRANSMISSION WITH FIVE (5) QUARTS OF DEXRON II AUTOMATIC TRANSMISSION FLUID.

8. CHECK TRANSMISSION FLUID LEVEL AND ADD AS REQUIRED.

A. PLACE TRANSMISSION IN "PARK" AND LEAVE IN "PARK". APPLY PARKING BRAKE AND BLOCK WHEELS START ENGINE AND LET IDLE (CARBURETOR OFF FAST IDLE STOP.) DO NOT RACE ENGINE. MOVE THE LEVER THROUGH THE RANGES.

B. VEHICLE ON LEVEL SURFACE.

C. CHECK OIL LEVEL ON DIPSTICK.

THE OIL LEVEL AT ROOM TEMPERATURE OF APPROXIMATELY 70 DEG F (21 DEG C) SHOULD BE 13 MM (1/2") ABOVE THE "FULL" MARK, OR BETWEEN THE TWO DIMPLES ON THE DIPSTICK. (THIS IS DUE TO A HIGHER THAN NORMAL OIL LEVEL IN THE PAN AS THE THERMO-ELEMENT DOES NOT OPEN UNTIL OIL WARMS UP). THE OIL LEVEL WILL DROP TO BETWEEN THE "ADD" AND "FULL" MARKS AS TRANSMISSION WARMS UP TO NORMAL OPERATING TEMPERATURE.

DO NOT OVERFILL TRANSMISSION, AS THIS MAY CAUSE FOAMING AND LOSS OF OIL THROUGH THE VENT.

8. INSEPCT TRANSMISSION OIL PAN AND NEW AXLE SEAL FOR ANY LEAKS. CORRECT AS REQUIRED.

WARRANTY INFORMATION

WHEN PERFORMING THE REPAIRS OUTLINED IN THE SERVICE PROCEDURE OF THIS BULLETIN, SUBMIT CLAIM FOR CREDIT AS FOLLOWS:

INSPECT CARRIER BORE AND REPLACE RIGHT DRIVE AXLE SEAL - USE LABOR OPERATION T0090 FOR .8 HR., USE TROUBLE CODE 92 AND LIST SEAL PART NUMBER 8631156 AS FAILED PART.

INSPECT CARRIER BORE, REPLACE RIGHT DRIVE AXLE SEAL AND REPLACE DIF- FERENTIAL CARRIER AND GEAR KIT - USE OPERATION NUMBER T0091 FOR 5.4 HR. ON 1980 MODEL VEHICLES, AND 6.2 HR ON 1981 MODEL VEHICLES, USE TROUBLE CODE 92 AND LIST THE CARRIER PART NUMBER 8637972 AS FAILED PART.

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.