SMU - SECTION 6A - ENGINE MECHANICAL REVISED

SUBJECT: SERVICE MANUAL UPDATE-SECTION 6A-ENGINE MECHANICAL REVISED CRANKSHAFT BALANCER SERVICE PROCEDURE AND SPECIAL TOOL

MODELS: 1995-96 BUICK LESABRE, PARK AVENUE, REGAL, RIVIERA 1995 CHEVROLET LUMINA APV 1995-96 CHEVROLET CAMARO 1995 OLDSMOBILE SILHOUETTE 1995-96 OLDSMOBILE EIGHTY EIGHT, NINETY EIGHT 1995 PONTIAC TRANS SPORT 1995-96 PONTIAC BONNEVILLE, FIREBIRD WITH 3800 ENGINE (VINS K, L, 1--RPOS L36, L27, L67)

THE PROCEDURE USED TO SERVICE THE CRANKSHAFT BALANCER HAS BEEN REVISED. USE THE FOLLOWING PROCEDURE TO PROPERLY SERVICE THE CRANKSHAFT BALANCER ON THE 1995-96 3800 ENGINES.

THERE HAS BEEN A RUNNING DESIGN CHANGE IN THE CRANKSHAFT BALANCER. THIS CHANGE AFFECTS 3800 ENGINES BUILT LATE IN THE 1995 MODEL YEAR (L27 AND L36) AND ALL OF 1996 MODEL YEAR (L36 AND L67). REFER TO THE APPROPRIATE SECTION IN THE SERVICE MANUAL IF YOU HAVE THE PREVIOUS DESIGN CRANKSHAFT BALANCER. REFER TO THE FOLLOWING PROCEDURE USING (J-38197-MOD) FOR THE REVISED DESIGN CRANKSHAFT BALANCER. THE CRANKSHAFT BALANCER DESIGNS CAN BE EASILY IDENTIFIED BY THE FOLLOWING:

ART SP0L3602 FIGURE 1 CRANKSHAFT BALANCER DESIGNS

PREVIOUS CRANKSHAFT BALANCER DESIGN HAS A DIMPLE STAMPED IN THE FACE OF THE CRANKSHAFT BALANCER. FIGURE 1 VIEW B. THIS DIMPLE AIDS IN THE ALIGNMENT OF J-38197-2 AND ALSO IDENTIFIES THE CRANKSHAFT KEY LOCATION IN RELATION TO THE SLOT IN THE CRANKSHAFT BALANCER. THE SPECIAL TOOL (J-38197) AND THE SERVICE PROCEDURE USED TO SERVICE THE PREVIOUS DESIGN CRANKSHAFT BALANCER HAVE NOT BEEN REVISED. REFER TO APPLICABLE SERVICE MANUAL AND SECTION FOR CORRECT SERVICE PROCEDURES.

REVISED CRANKSHAFT BALANCER DESIGN HAS A ROUND HOLE DRILLED IN THE FACE OF THE CRANKSHAFT BALANCER. FIGURE 1 VIEW A. THIS HOLE DOES NOT AID IN THE ALIGNMENT OF J-38197-2, LIKE THE DIMPLE ON THE PREVIOUS DESIGNED CRANKSHAFT BALANCER. THE HOLE IS USED TO IDENTIFY THE CRANKSHAFT KEY LOCATION IN RELATION TO THE SLOT IN THE CRANKSHAFT BALANCER. THE SPECIAL TOOL (J-38197) HAS BEEN REVISED TO REFLECT THE DESIGN CHANGES AND THE NEW TOOL IS J-38197-MOD. (IF YOU ALREADY HAVE J-38197 IT IS NECESSARY TO ONLY ORDER THE J- 38197-MOD). THE REVISED CRANKSHAFT BALANCER REQUIRES THE USE OF THREE BOLTS (J-38197-4), THESE BOLTS ARE 1/4 INCH LONGER THAN THE PREVIOUS DESIGN. J-38197-4 ARE SILVER IN COLOR WHILE THE PREVIOUS TOOL USES BLACK BOLTS.

J-38197-4 SHOULD NOT BE USED TO SERVICE THE PREVIOUS DESIGN CRANKSHAFT BALANCER AS DAMAGE TO THE BALANCER MAY OCCUR BY USING THE LONGER BOLTS.

THE REVISED CRANKSHAFT BALANCER MAY HAVE BURRS ON THE SLOTTED ACCESS HOLES THAT DO NOT ALLOW THE PROPER ALIGNMENT OF J-38197. IF BURRS ARE PRESENT, REMOVE THEM BY USING ONE OF THE FOLLOWING METHODS:

* FILE ACCESS HOLE USING RAT-TAIL FILE IN PROPER LOCATION. * DRILL ACCESS HOLE USING DRILL IN PROPER LOCATION. * BEND ACCESS HOLE USING SCREW DRIVER IN PROPER LOCATION.

REVISED CRANKSHAFT BALANCER SERVICE PROCEDURE

FIGURES 1, 2 AND 3

TOOLS REQUIRED:

J-36660 TORQUE ANGLE METER J-37096 FLYWHEEL HOLDING TOOL J 38197-A AND J-38197-MOD CRANKSHAFT BALANCER PULLER J 38197-A INCLUDES: J 38197-1 PILOT SCREW J 38197-2 PULLER PLATE J 38197-3 PULLER SCREWS (BLACK) J-38197-4 PULLER SCREWS (SILVER) J-38197-MOD INCLUDES: J-38197-4 PULLER SCREWS (SILVER)

REMOVE OR DISCONNECT

1. HOLD FLYWHEEL USING J-37096 (FIGURE 2). ART HN0236A8 FIGURE 2 HOLDING FLYWHEEL USING J-37906 2. CRANKSHAFT BALANCER BOLT. 3. CRANKSHAFT BALANCER USING J-38197-A AND J-38197-MOD (FIGURE 3). A. INVERT J-38197-2 SO THAT THE LEG OF THE TOOL IS FACING AWAY FROM THE CRANKSHAFT BALANCER. B. INSTALL THE SILVER SCREWS (J-38197-4) TO CRANKSHAFT BALANCER. C TURN J-38197-1 TO REMOVE CRANKSHAFT BALANCER FROM CRANKSHAFT. D. REMOVE J-38197-1, 2 AND 4 FROM CRANKSHAFT BALANCER.

ART HV9496A8B FIGURE 3 REMOVING CRANKSHAFT BALANCER USING J-38197-MOD

IMPORTANT

* THE CRANKSHAFT BALANCER IS SERVICED AS AN ASSEMBLY. DO NOT ATTEMPT TO SEPARATE PULLEY FROM BALANCER HUB.

INSTALL OR CONNECT

1. LUBRICATE CRANKSHAFT AND INSIDE OF BALANCER WITH CLEAN ENGINE OIL. 2. CRANKSHAFT BALANCER USING THE SMALL HOLE TO AID IN THE ALIGNMENT OF CRANKSHAFT KEY. 3. CRANKSHAFT BALANCER BOLT. * HOLD FLYWHEEL USING J-37096. TIGHTEN * BOLT TO 150 N.M (111 LB. FT.) + 76 DEGREES USING J-36660.

FIGURES: 3 ATTACHMENTS: 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.

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