Exhaust - Moan/Boom at Highway Speeds

Bulletin No.: T-93-68
File in Group: 16
Number: 37
Corp.Ref.No.: 336601R
Date: March, 1993

SUBJECT:
EXHAUST MOAN/BOOM AT HIGHWAY SPEEDS

MODELS AFFECTED:
1991-1992 BROUGHAMS (RWD)
1993 FLEETWOODS (RWD) AND FLEETWOOD BROUGHAMS (RWD)

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 N-m (17 lbs.ft.) and hanger clamp to 33 N-m (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.