DIESEL ENGINE BOOM/NOISE TRANSMISSION TO ENGINE BOLTS

Some 1983 El Caminos equipped with 5.7L diesel engine (Code N) and THM 350C automatic transmissions (MX2) may exhibit an engine boom noise periods at 1220, 1450 and 1600 rpm. To reduce these noise periods, the vehicle's transmission case to engine lower bolt attachment (see illustration) needs to be revised as follows:

Remove transmission case to engine lower left and lower right attaching bolts and coat with thread locking compound Loctite #271, Service P/N 1052624 or equivalent may be used.

Reinstall bolts and torque to 47 N.m (35 ft. lbs.).

After torquing, back out each lower bolt 1/3 turn (1200

Labor Operation Number: T1093 Labor Time : .3 hours

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.