VIBRATION/BOOM HT4100 ENGINE REAR GEN. TO EXH. MAN. BRACE

HT4100 ENGINE VIBRATION/BOOM - 1982 C-CAR

Some 1982 C-cars equipped with HT4100 engines may exhibit a vibration and/or boom in the 900-1100 RPM, 1600-1700 RPM, and/or 1900-2200 RPM ranges. This condition is due to the vibration of the rear generator to exhaust manifold brace (refer to Figure 1).

A revised brace (P/N 1627687) has been released to correct this condition and went into production at the beginning of the 1983 model year. The material thickness of the revised brace has been increased to 2mm as compared to the previous brace material thickness of 1mm.

The revised brace is available through GMWDD and should be installed to correct 1982 C-cars exhibiting this condition.

For warranty purposes, use Operation Number J4140 at .2 hour.

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.