WHEEL AND TIRE VIBRATION FRAME MOUNTS/REPAIR PROCEDURE

WHEEL AND TIRE VIBRATION AT HIGHWAY SPEEDS

VEHICLES AFFECTED: 1986 ELDORADO AND SEVILLE -----------------

Some 1986 Eldorados and Sevilles may experience a 1st order wheel and tire vibration at highway speeds. This vibration will appear to be most pronounced in the floor pan and seats.

To repair this condition, use the following procedure*:

1. Verify on-car wheel and tire radial runouts are less than .050 inches total indicator reading. Refer to section OC of the Allante Service Information Manual for procedures on checking on-car runout.

2. Verify Tire and Wheel balance. An off-car dynamic balance is recommended. An on-car finish balance may also be needed.

3. Install the parts listed below in positions #1 - #3, following the procedure listed in the appropriate Service Information Manual (refer to Figure 1).

Quantity P/N Description -------- --- -----------

6 1627359 Insulator 6 1626368 Spacer 6 11503690 Bolt 12 11508382 Nut

4. Torque frame insulator 0295 bolts to 100 Nm (74 ft.lbs.) in the following order:

lst-#2 position on the left hand side 2nd-#l position on the left hand side Remainder of bolts can be torqued in any order.

* Installation of the frame insulators listed above may result in a slightly harsher ride.

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.