REVISED:POP NOISE WHEN BRAKING FORE / AFT SHIFT OF FRAME

ALL 1984-86 6000 MODELS (APPLICABLE TO 1986 MODELS PRIOR TO BREAKPOINTS) AND 1984 PHOENIX MODELS

"Please discard previous bulletin 85-2-10 due to this revision which includes 1986 6000 models aseembled prior to dates and VIN breakpoints noted below-by assembly plant."

Oshawa #1 ---------- 2/7/86 2G2AG19XOG9268024

Tarrytown

1/17/86 1G2AF27X1GT228880

Some 1984-86 6000 models and 1984 Phoenix models may exhibit a popping type noise during braking and acceleration. The popping noise, caused by a fore and aft shifting of the cradle, can be felt as "oil canning" in the floor pan. (The popping noise should not be confused with a "click" or 'clunk" felt in the steering wheel -- covered in Pontiac Dealer Service Bulletin 84-3-14). Another similar sounding noise, "crunching," could be caused by loose cradle mount bolts. Torque should be 85 ft. lbs. (115 N.m).

If the noise is still present after tightening the cradle bolts, it can be corrected by installing shims on both rear cradle mount insulators as shown. The intent of this fix is to create an interference fit using shims. Multiple shims may be used if necessary.

Shims may be fabricated from any available steel or brass shim stock. Thickness should be approximately .025" to .040".

The following procedure should be followed when installing shims:

1. Support cradle with a jack stand on the rear cross member.

2. Remove one (1) rear cradle bolt at a time and lower the jack stand enough to remove pressure from the mount.

CAUTION:

Damage to the steering intermediate shaft could esult if the cradle is lowered more than required rto free the mount.

3. Form shim to mount as shown and reinstall mount. Some rubber lube may be required to ease assembly.

4. Reinstall mount bolt. Torque to 85 ft. lbs. (115 N.m).

5. Repeat above procedure on other rear corner.

Labor Operation Number: E1040

Labor Time .5 hours

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.