Interior - Moan/Vibration 45-55 MPH

9230buick02

Bulletin: 92-10-46

Date: June '92

Ref. No.: 92-220-10

Corp. Ref. No.: 237101


SUBJECT:
MOAN/VIBRATION 45-55 MPH
(MATCH MOUNT PROPELLER SHAFT, ALIGN EXHAUST SYSTEM,
INSTALL BRACE)

MODELS AFFECTED:
1992 ROADMASTER SEDANS WITH 2.56 AXLE RATIO (RPO GM8)


CONDITION:

Some 1992 Roadmaster sedans with 2.56 ratio rear axles (RPO GM8), and assembled prior to VIN breakpoint NR464131, may exhibit a slight vibration/moan condition. This condition is most apparent during light acceleration from 45-55 mph on a grade, with transmission in 4th gear and torque converter clutch (TCC) applied.

CAUSE:

This vibration/moan condition may be attributable to one or more of the following causes that may excite vehicle underbody.

Cause 1:
Incorrect match mounting of propeller shaft to rear axle
assembly.

Cause 2:
Misalignment of exhaust system.

Cause 3:
Frame rail vibration at rear of vehicle.

CORRECTION:

To insure correction of complaint vehicles, all of the following three corrective action steps must be performed:





Correction 1:
Inspect and correct, as required, the match mounting of propeller shaft to rear axle assembly following procedure shown on Figure 1.





Correction 2:
Align exhaust system following procedure shown on Figure 2.





Correction 3:
Install new frame brace, P/N 10225142, to rear frame rails, at lower energy absorber attachments following procedure shown on Figure 3.


Part Availability:

Parts are expected to be available on June 29, 1992. Until then normal part orders will not be accepted by GMSPO. In an emergency, contact your division service department for the required parts order authorization.

WARRANTY INFORMATION:

Labor Operation Number: T1863
Labor Time: .6 Hour