REMANUFACTERED HT4100 SERVICE ENGINE BEARING KNOCK. Cadillac Limousine 1985

For 1990-2009 cars

# REMANUFACTERED HT4100 SERVICE ENGINE BEARING KNOCK

#### MODELS AFFECTED: 1982-1985 RWD DE VILLES AND BROUGHAMS 1982-1985 ELDORADOS AND SEVILLES

Some 1982-1985 RWD DeVilles and Broughams and 1982-1985 Eldorados and Sevilles that have had remanufactured service engine assemblies installed between December 1, 1988 and January 31, 1989 may experience a light main bearing knock (mallet noise). These longitudinal service engine assemblies are part numbers 12336132 through 12336137 and may be identified because they are entirely painted black (original engines are natural aluminum finish on the cylinder block and intake manifold). The noise may be caused by improper bearing selection during manufacture.

To repair this condition use the following procedure:

1. Locate engine I.D. plate on right-hand side of crankcase just above the oil pan rail of #6 cylinder.

2. Plate contains a sequential identification number. If I.D. number is lower than 61593, proceed to step 3. If bearing knock is experienced with I.D. number 61593 or higher, call CAD-STAR.

3. Obtain the undersize dimension for the main bearings (0.010" or 0.020") from the I.D. plate.

4. From the chart below, select the equivalent bearings for positions 1, 2, 4, and 5.

5. Replace these main bearings by following the Service Manual procedure described on page 6A-25 of the 1988 Eldorado/Seville Service Information Manual. Note that additional undersize bearings (0.011" or 0.021") described for position 1 are not available.

6. If bearing knock persists after replacement, call CAD-STAR.

For warranty purposes use Labor Operation T6373 at 2.1 hours for C/D series vehicles or 3.3 hours for E/K vehicles.

#### Undersize Main Bearings for Remanufactured Engines

Bearing Position Size P/N ---------------- ---- --- #1 -0.010" 12337121 -0.020" 12337122

#2, #4 -0.010" 12337123 -0.020" 12337124

#5 -0.010" 12337127 -0.020" 12337128

Parts are currently available from GMSPO.

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.