Diesel - Engine, Fuel Repair Information Bulletins

Number 83-I-55 Section 6B Date 04/83
Subject: DIESEL INFORMATION BULLETINS

^ ENGINE MISS AND EXHAUST SMOKE AT HIGHWAY SPEEDS - 1982 AND 1983 V-6 DIESEL ENGINES (VIN CODE T)

An engine miss followed by a puff of blue smoke out the exhaust may be caused by engine oil leaking into the intake area of the cylinder head. The pipe-thread plugs that cover the upper Torx(R) head bolts may be the source of an oil leak if not fully seated.

^ DIESEL INJECTION PUMP REPAIR PARTS

Diesel engine injection pump repair parts are now available through WDDGM. Repair parts available are listed in the current parts catalog groups 3.300 through 3.340.

^ MAIN BEARING BOLT HOLES - 1983 V-6 DIESEL ENGINE (VIN CODE "T")

Main bearing bolt hole thread pitch for #2 and #3 main bearings have been changed from 1.75 mm to 1.76 mm on V-6 diesel engines. The main bearing bolt has not changed. This results in an interference fit with the last few threads when the bolt is screwed into the hole. This interference spreads the load throughout the bulkhead rather than concentrating it at the surface. Engine blocks that have a main bearing bolt hole pitch of 1.76 mm for #2 and #3 main bearings are identified by a stamped letter "G" behind the cast part number. The cast part number is located on the top rear of the block next to the oil pump drive assembly. When installing these bolts it is essential that engine oil be applied to the threads to prevent galling. It is normal for the bolt to tighten up slightly during the last few turns upon installation. Do not attempt to "clean up" #2 and #3 main bearings block threads by retapping with standard tap size M12-1.75. The M12-1.76 tap used is not a standard tap size.