18NA021

File in Section:
Bulletin No.:
Service Bulletin
Date:
18-NA-021
January, 2018
TECHNICAL
Subject:
Premature Rear Tire Wear on Inside Edge
Brand:
Model:
Buick
Cascada
Model Year:
VIN:
from
to
2016
2018
from
Engine:
Transmission:
to
Involved Region or Country
North America
Condition
Some customers may comment about premature wear on the inside edge of the rear tire.
Cause
This condition may be caused by the rear alignment being out of specifications.
Correction
Verify the customer concern and adjust the rear alignment by adding shims behind the
rear hub assembly.
Service Procedure
1. Install the alignment equipment according to the
manufacturer's instructions.
2. Jounce the front and rear bumpers three times
prior to checking the wheel alignment.
3. Measure the rear alignment angles and record the
readings.
4. Access the worksheet located in the “Service
Forms” application of GlobalConnect.
Copyright 2018 General Motors LLC. All Rights Reserved.
Page 2
January, 2018
Bulletin No.: 18-NA-021
4896062
5. Enter recorded values to determine which shims to
use in alignment correction.
6. Record shim part numbers and locations.
4896244
Important: The hub bolts are Torque to Yield and must
be replaced.
7. Remove the rear wheel bearing and hub assembly
(3). Refer to Rear Wheel Bearing and Hub
Replacement in SI.
8. Discard the bolts that secure the wheel bearing
and hub assembly to the suspension knuckle.
9. Clean the wheel bearing/hub and suspension
knuckle surfaces (2).
10. Install the pre-determined shims (1) onto the studs,
between the wheel bearing/hub and the
suspension knuckle as recorded.
11. Install the rear wheel bearing and hub assembly.
Bulletin No.: 18-NA-021
January, 2018
Page 3
12. If necessary, repeat above steps for the other side.
13. Recheck rear alignment and road test the vehicle.
Parts Information
Causal
Part
Description
Part
Number
Qty
ALIGNMENT
SHIM, REAR
(.015 in Shim
Thickness)
19306037
1
ALIGNMENT
SHIM, REAR
(.030 in Shim
Thickness)
19306038
1
ALIGNMENT
SHIM, REAR
(.010 in Shim
Thickness)
19306915
1
ALIGNMENT
SHIM, REAR
(.020 in Shim
Thickness)
19306916
1
Bolt, Rear Axle
Caliper Bracket
11588742
4 per side
Warranty Information
For vehicles repaired under the Bumper-to-Bumper
coverage (Canada Base Warranty coverage), use the
following labor operation. Reference the Applicable
Warranties section of Investigate Vehicle History (IVH)
for coverage information.
Labor
Operation
Description
Labor Time
8080368*
Adjust Rear Alignment Using
Shims
1.3 hrs
Add
Shim Other Side
0.6 hr
*This is a unique Labor Operation for Bulletin use only.
Version
1
Modified
Released January 22, 2018
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
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 your GM dealer for information on whether your vehicle may benefit from the
information.
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