INFORMATION ON INTERMEDIATE SPROCKET REVISION. Cadillac DeVille 1994

REVISION: 09/23/94

THIS BULLETIN IS REVISED TO CORRECT AN RPO INITIALLY IDENTIFIED INCORRECTLY, UPDATE THE PARTS AVAILABILITY STATEMENT, AND ADD A NOTE SPECIFIC TO OLDSMOBILE APPLICATIONS. PLEASE DISCARD BULLETIN 476122 (GROUP REFERENCE 6 - ENGINE). ______________________________________________________________________

SUBJECT: INFORMATION ON INTERMEDIATE SPROCKET REVISION

MODELS: 1994-95 CADILLAC CONCOURS, ELDORADO AND SEVILLE WITH 4.6L ENGINE (VINS Y AND 9 - RPOS LD8 AND L37)

1995 OLDSMOBILE AURORA WITH 4.0L ENGINE (VIN C - RPO L47)

THE CAMSHAFT DRIVE INTERMEDIATE SHAFT AND SPROCKET IN ENGINES BUILT AFTER APRIL 21, 1994 ARE REVISED TO IMPROVE WEAR CHARACTERISTICS (SEE FIGURE 1). THE INITIAL (FIRST) DESIGN SHAFT AND SPROCKET CONSIST OF A SHAFT WITH AN OIL GROOVE AND A PLAIN SPROCKET BUSHING. THE REVISED (SECOND) DESIGN USES A PLAIN SHAFT AND A **GROOVED** SPROCKET BUSHING.

DURING ENGINE SERVICE, IT IS IMPORTANT THAT A SECOND DESIGN SHAFT (WITHOUT OIL GROOVE) AND A FIRST DESIGN (PLAIN BUSHING) SPROCKET ARE NEVER MATED TOGETHER. DOING SO WOULD RESULT IN ESSENTIALLY NO LUBRICATION AND VERY ADVANCED WEAR. REPLACEMENT IS INDICATED IF CLEARANCE BETWEEN THE SHAFT AND BUSHING IS GREATER THAN 0.10 MM (0.004"). NORMALLY, WEAR WILL BE EXPERIENCED IN THE BUSHING (SPROCKET) AND NOT THE SHAFT. REPLACEMENT OF THE SPROCKET WHICH PUTS A GROOVED (SECOND DESIGN) BUSHING AGAINST A GROOVED (FIRST DESIGN) SHAFT IS AN ACCEPTABLE CONDITION.

NOTE: AT THE TIME OF PRINTING, THE OLDSMOBILE AURORA 4.0L ENGINE IS IN AN EXCHANGE PROGRAM. MAKE NO ATTEMPT TO REPAIR THIS UNIT. THIS BULLETIN IS PROVIDED FOR YOUR INFORMATION AS IT MAY BE USED IN THE FUTURE WHEN THE 4.0L ENGINE IS NO LONGER INVOLVED IN THE 1995 MODEL YEAR ENGINE EXCHANGE PROGRAM.

PART INFORMATION:

PART NUMBERS ARE AS FOLLOWS: FIRST DESIGN SECOND DESIGN ------------ ------------- INTERMEDIATE SHAFT 1647457 3543605 INTERMEDIATE SPROCKET 3522477 3543604

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

LABOR OPERATION: J0840 USE PUBLISHED LABOR OPERATION TIME.

FIGURES: 1

Object Number: 82897 Size: FS

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.