WHEEL AND TIRE VIBRATION FRAME MOUNTS/REPAIR PROCEDURE

MODELS AFFECTED: 1986 ELDORADOS AND SEVILLES

Some 1986 Eldorados and Sevilles may experience a first order wheel and tire vibration at highway speeds. This vibration will appear to be most pronounced in the floor pan and seats and will register in the 12-17 Hz range on a reed tachometer (refer to Serviceman Bulletins T-86-4 and T-87-104).

To repair this condition, use the following procedure*:

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

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

3. Install the frame insulators 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 (1) 6 1626368 Spacer (2) 6 11503690 Bolt (3) 18 11508382 Nut (4)

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

lst: #2 position on the left hand side 2nd: #1 position on the left hand side

NOTE: Remainder of the bolts can be tightened in any order.

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

For warranty purposes, use Labor Operation T6241 at 1.2 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.