SMU - SECTION 6B - ENGINE MECHANICAL - OIL RING

SUBJECT: SERVICE MANUAL UPDATE--SECTION 6B--ENGINE MECHANICAL-- OIL RING EXPANDER INSTALLATION REVISION

MODELS: 1993 CADILLAC ALLANTE 1993-97 CADILLAC SEVILLE, ELDORADO 1994-97 CADILLAC DEVILLE, CONCOURS 1997 CADILLAC DEVILLE D'ELEGANCE 1995-97 OLDSMOBILE AURORA WITH 4.6L NORTHSTAR/4.0L V8 (VINS 9,Y,C - RPOS L37,LD8,L47)

WHENEVER REMOVAL AND INSTALLATION OF THE PISTON RINGS OF A 4.6L NORTHSTAR OR 4.0L AURORA ENGINE IS NECESSARY, YOU MUST INSTALL THE OIL RING EXPANDER (FIGURE 1, #8) WITH THE ENDS OF THE EXPANDER FACING TOWARD THE TOP OF THE PISTON (FIGURE 2, #1).

INSTALLING THE EXPANDER WITH THE ENDS FACING AWAY FROM THE TOP OF THE PISTON COULD PREVENT THE OIL RINGS FROM ROTATING DURING ENGINE OPERATION. THIS CONDITION COULD PRODUCE ABNORMAL WEAR CHARACTERISTICS OR AFFECT OIL CONSUMPTION.

PLEASE UPDATE THE APPROPRIATE SECTION OF YOUR SERVICE MANUAL WITH THIS INFORMATION.

FIGURES: 2 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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