Tire - Irregular Wear
Bulletin No. 86-49AFile in Group 3E
Number 23
Corp. Ref. No. 806 0509-5
Date May '86
SUBJECT: IRREGULAR TIRE WEAR
MODELS AFFECTED: 1985-1986 FLEETWOOD BROUGHAM AND 1985 ELDORADO AND SEVILLE WITH ALL SEASON TIRES
This bulletin supersedes Serviceman Bulletin T-86-49, Group 3E, which should be destroyed. The labor operation originally listed as T6149 has been changed to T6151.
Condition
Some 1985-1986 Fleetwood Broughams and 1985 Eldorados and Sevilles may experience irregular tire wear on non-drive axles with original equipment all season tires (with "M&S" rating on sidewall). The wear may be identified as a cupping or heel and toe condition, usually on the outer shoulder of the tire. If allowed to continue, premature wear of tread may occur.
Cause
The single, most contributing cause of this type of wear, except for abusive driving, is excessive toe-in. Lack of tire rotation and low inflation pressures will also exaggerate this condition.
Service Procedure
Tire wear should be inspected:
FIGURE 1 - EVALUATING UNIROYAL TIRE WEAR:
FIGURE 2 - MODIFIED "X" ROTATION PATTERNS FOR FRONT AND REAR WHEEL DRIVE VEHICLES:
1. If only slight cupping is noticed, and the cross grooves in the tire outside shoulder are still visible (see Figure 1), tires should be rotated using the modified "X" rotation pattern (see Figure 2). The vehicle alignment should then be checked and reset if necessary to the new alignment specifications in this bulletin. Both before and after alignment measurements must be recorded on the Repair Order. The importance of regular tire rotation and proper inflation pressures must be stressed to the customer.
FIGURE 1 - EVALUATING UNIROYAL TIRE WEAR:
2. If the cupping is severe and/or the cross grooves in the outside shoulder are not visible (see Figure 1), tire replacement will be necessary. A maximum of two replacement tires will be available for vehicles under 12 months and 12,000 miles. Replacement tires must be obtained directly from Uniroyal tire company by calling the following toll-free number:
1-800-231-5893 (outside Texas) 1-800-833-5906 (in Texas)
Dealers must supply owner's name, VIN, mileage, dealer code and tire size and model (e.g., Royal Seal). Tires will be furnished on a direct bill basis to dealers. The bill from Uniroyal will contain the vehicle VIN; dealers should retain a copy of this bill for their records. Any claims submitted which are not substantiated by Uniroyal will be debited for the entire amount of the claim.
Old tires must be held for scrapping by a Cadillac representative. They must be rendered unusable by drilling four holes through the tire serial number, located on the back sidewall.
FIGURE 3 - MATCH MOUNTING THE WHEEL LOW POINT WITH THE TIRE HIGH POINT:
Mount new tires aligning the yellow mark on the tire with the valve stem on the wheel (see Figure 3). Balance and install on non-drive axle positions. Check alignment of non-drive axle and reset as necessary; see new alignment specifications in this bulletin. Both before and after alignment measurements must be recorded on the R.O. Stress the importance of regular tire rotation and proper inflation pressures to the customer.
Revised Fleetwood Brougham Front Alignment Specifications
Toe: Per Wheel .06~ +/- .05~
Sum .12~ +/- .10~
Camber: .25~ +/- .25~
Caster: 3.00~ +/- .50~
Revised Eldorado and Seville Rear Alignment Specifications
Toe: Sum .10~ +/- .10~
For warranty purposes, use one of the following labor Operations:
FAILURE LABOR LABOR NET
DESCRIPTION CODE OPERATION HOURS ITEM
^ Rotate tires using modified 06 T-6151 * -- X rotation (includes lock nuts) and align front or rear suspension
* Fleetwood Brougham (front suspension) 1.4 Hrs.
Eldorado and Seville (rear suspension) 1.2 Hrs.
^ Mount and balance two tires 06 T-6150 ** *** (includes lock nuts) and align front or rear suspension
* * Fleetwood Brougham (front suspension) 1.7 Hrs.
Eldorado and Seville (rear suspension) 1.5 Hrs.
Dealers are eligible for .2 administrative allowance as "other labor hours" if tires are replaced.
* * * The Uniroyal tire invoice amount should be entered as a net item on the warranty claim.