Wheels/Tires - Vibrations At Highway Speeds
87cadillac8Bulletin No. T-88-40
File in Group 3E
Number 26
Corp. Ref. No. 613501R
Date Nov. '87
SUBJECT: WHEEL AND TIRE VIBRATIONS AT HIGHWAY SPEEDS
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 die 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.
FIGURE 1 - FRAME INSULATORS:
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 N-m (74 ft.lbs.) in the following order:
1st: #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.