1500 RPM BOOM CATALYTIC CONVERTER DAMPENER

Model and Year 1982-84 CELEBRITY AND CITATION VEHICLES EQUIPPED WITH LR8 ENGINE (INCLUDING 1984 CELEBRITY WAGONS)

CONDITION

Some 1982-84 Celebrity and Citation vehicles equipped with the LR8 engine may exhibit a loud booming noise at 1500 rpm.

CAUSE

This condition may be caused by the catalytic converter hanger being preloaded.

CORRECTION

To correct this condition, the following procedures should be followed.

1. Remove the load from the catalytic converter exhaust hanger.

a. Loosen the converter and manifold flange joint bolts.

b. Break the converter joint loose.

c. Retighten the bolts to 20-40 N.m (15-30 ft. lbs.) while holding the converter up against the heat shield.

d. Make sure the distance between the upper and lower converter hanger rivets is less than 62mm.

2. Install a newly released additional cradle dampener assembly (see illustration).

P/N Description --- ----------- 22527158 Dampener Assembly

10021800 Bolt

Do not remove the existing dampener.

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.