Some 1991-1992 Broughams (RWD) and 1993 Fleetwoods (RWD) and Fleetwood Broughams (RWD) may experience a slight exhaust moan/boom condition that is most apparent during light acceleration from 45-55 mph with transmission in fourth gear and Torque Converter Clutch (TCC) applied.
This condition may occur due to exhaust-generated pulsations transmitted into the vehicle underbody through the exhaust system hangers.
A revised muffler hanger assembly can be installed to correct this condition.
To repair this condition use the following procedure:
1. Raise vehicle.
2. Support intermediate pipe assembly.
3. Remove muffler hanger assembly.
4. Install new muffler hanger assembly, P/N 10228003, and torque hanger/frame bolt to 24 Nm (17 lbs. ft.) and hanger clamp to 33 Nm (24 lbs. ft.). Refer to Figure 1.
5. Align muffler and intermediate pipe to proper clearance.
Parts are currently available from GMSPO.
For warranty purposes use Labor Operation T3301 at .6 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.