17NA406

File in Section:
Bulletin No.:
Service Bulletin
Date:
17-NA-406
December, 2017
TECHNICAL
Subject:
Driveline Shudder Under Hard Acceleration Felt in Seat
Brand:
Model:
Cadillac
XTS
Model Year:
VIN:
from
to
2016
2018
from
Engine:
Transmission:
to
LF3
Involved Region or Country
North America
Condition
Some customers may comment that a vibration is felt under heavy acceleration around
20 mph (32 km/h), which can be felt in the seat.
Cause
This condition may be caused by a second order vibration from the cardan joint.
Correction
4921286
If the vehicle has been validated to have a driveline shudder under heavy acceleration
around 20 mph (32 km/h), install 4.5 mm thick shims (1) on top of the front RDM isolator
bushings.
Copyright 2017 General Motors LLC. All Rights Reserved.
Page 2
December, 2017
Service Procedure
1. Raise and support the vehicle. Refer to Lifting and
Jacking the Vehicle in SI.
Bulletin No.: 17-NA-406
4. Position the flat washer (1) over the differential
mount washer (2).
5. Loosely install the bolt enough to support the
differential.
6. Remove the other front differential bolt and position
the washer over the differential mount washer.
7. Install the bolt.
8. Tighten the bolts to specifications. Refer to
Fastener Specifications in SI.
Parts Information
Causal
Part
Description
Part
Number
Qty
WASHER, FLAT,
14X42.5X3.61
MM, SAE 1050
STL RC 37-43,
7112M
11562546
2
Warranty Information
2279896
For vehicles repaired under the Powertrain coverage,
use the following labor operation. Reference the
Applicable Warranties section of Investigate Vehicle
History (IVH) for coverage information.
2. Remove one of the front differential bolts (1).
3. Loosen the opposite side front differential
mount bolt.
Labor
Operation
Description
Labor Time
3080268*
Test Drive and Install Flat
Washer on the Front
Differential Mount
0.5 hr
*This is a unique Labor Operation for Bulletin use only.
4921289
Version
1
Modified
Released December 19, 2017
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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