SMU - SECTION 6A2 - ENGINE MECHANICAL. Cadillac Concours 1996

REVISION: 03/07/96

THIS BULLETIN IS BEING REVISED TO CHANGE VALVES SPECIFICATIONS AND TO ADD TORQUE SPECIFICATION. PLEASE DISCARD BULLETIN 57-61-34 (SECTION 6 - ENGINE). ----------------------------------------------------------------------

SUBJECT: SERVICE MANUAL UPDATE - SECTION 6A2 - ENGINE MECHANICAL - NEW HARMONIC BALANCER INSTALLATION TOOL, REVISED ENGINE SPECIFICATIONS, AND OIL PAN TORQUE SPECIFICATION

MODELS: 1996 CADILLAC CONCOURS, DEVILLE, ELDORADO, SEVILLE WITH 4.6L ENGINES (VINS Y, 9 - RPOS LD8, L37)

1996 OLDSMOBILE AURORA WITH 4.0L ENGINE (VIN C - RPO L47)

THE FOLLOWING INFORMATION SHOULD BE ADDED TO SECTION 6A2--ENGINE MECHANICAL OF THE APPROPRIATE SERVICE MANUAL.

NEW HARMONIC BALANCER INSTALLATION TOOL 1996 MODEL YEAR ENGINES ARE EQUIPPED WITH A SMALLER DIAMETER M14 CRANKSHAFT BALANCER BOLT, WHICH REPLACES THE LARGER M18 BOLT. SINCE THIS NEW BOLT IS SMALLER IN DIAMETER, KENT MOORE TOOL NUMBER J39344 IS NO LONGER USED ON 1996 MODEL ENGINES. A NEW HARMONIC BALANCER TOOL J41998 IS NOW AVAILABLE AND MUST BE USED WHENEVER INSTALLATION OF THE HARMONIC BALANCER IS NECESSARY. THIS NEW BOLT HAS A REVISED TORQUE SPECIFICATION OF 50 N.M (37 LB FT) PLUS 120 DEGREES FOR INSTALLATION.

IMPORTANT: A SMALL NUMBER OF 1995 ENGINES WERE BUILT WITH CRANKSHAFTS EQUIPPED WITH THE M14 BOLT. IDENTIFY THE SIZE OF THE BOLT TO DETERMINE THE PROPER TORQUE SPECIFICATION.

REVISED ENGINE SPECIFICATIONS PLEASE ADD THE FOLLOWING REVISED ENGINE SPECIFICATIONS TO YOUR SERVICE MANUAL:

VALVES INTAKE VALVE SEAT WIDTH 0.450-0.850 MM (0.017-0.033 IN.) EXHAUST VALVE SEAT WIDTH 0.700-1.100 MM (0.027-0.043 IN.)

TORQUE SPECIFICATION OIL PAN BOLTS 10 NM (89 LB. IN.)

CRANKSHAFT AND MAIN BEARINGS MAIN BEARING CLEARANCE 0.015-0.055 MM (0.0006-0.002 IN.) MAIN BEARING JOURNAL, DIAMETER 64.352-64.364 MM (2.5335-2.5337 IN.) MAIN BEARING JOURNAL, OUT-OF-ROUND 0.006 MM (0.0002 IN.) MAIN BEARING JOURNAL, TAPER 0.004 (0.00015 IN.) MAIN BEARING JOURNAL LENGTH, NO. 2 24.6 MM (0.969 IN.) CRANKPIN DIAMETER 53.948-53.962 MM (2.1239-2.1245 IN.) CRANKPIN OUT-OF-ROUND 0.007 MM (0.0003 IN.) CRANKPIN TAPER 0.007 MM (0.0003 IN.) CRANKSHAFT ENDPLAY, NEW LIMITS 0.05-0.5 MM (0.002-0.020 IN.) CRANKSHAFT ENDPLAY, WORN LIMITS 0.5 MM (0.020 IN.) FLYWHEEL FLANGE RUNOUT 0.025 MM (0.001 IN.) MINIMUM REAR MAIN SEAL DIAMETER 95.76 MM (3.77 IN.) MAXIMUM REAR MAIN SEAL DIAMETER 95.98 MM (3.78 IN.)

SOME OF THESE REVISED SPECIFICATIONS APPLY TO PAST MODEL YEAR 4.0L AND 4.6L ENGINES. PLEASE CHECK YOUR PAST MODEL YEAR ENGINE MECHANICAL SECTIONS AND INSERT THESE REVISED SPECIFICATIONS.

PLEASE UPDATE THE ENGINE MECHANICAL SECTION 6A2 OF YOUR SERVICE MANUAL WITH THIS INFORMATION.

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