NHTSA ID Number: 10240187
Manufacturer Communication Number: 20-NA-175
TSB/Document Date: 2023-08-02
Summary
This technical bulletin provides repair information to correct a customer concern of vertical misalignment between cab and pickup box on driver side of vehicle.
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TSB/Document ID: 20-NA-175
Replacement Service Bulletin Number:
MFR Communication Date: 2023-07-27
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: STRUCTURE
MFR Component System:
MFR Component Subsystem:
Previous TSB | Next TSB |
Bulletin No.:
Service Bulletin
Date:
20-NA-175
August, 2023
TECHNICAL
Subject:
Vertical Misalignment Between Cab and Pickup Box on Driver Side of Vehicle
Brand:
Model:
Model Year:
from
to
2019
2019
2020
2021
2022
2022
Silverado 1500
2023
2024
Silverado
2500HD/3500HD
2020
2020
Sierra 1500
(New Model)
2019
2019
Sierra 1500
2020
2021
Sierra 1500 (LIMITED RPO J21,
12th VIN Digit = 4
or less)
2022
2022
Sierra 1500
2023
2024
Sierra
2500HD/3500HD
2020
2020
Silverado 1500 (New
Model - 12th VIN
Digit = 7) - 4WD
VIN:
from
Engine:
All
All
to
Silverado 1500
(New Model)
Silverado 1500
Chevrolet
Silverado 1500 (LTD, RPO J21, 12th
VIN Digit = 4 or less)
Silverado 1500 (RPO J22, 12th VIN
Digit = 5 or greater)
Sierra 1500 - (RPO
J22, 12th VIN Digit =
5 or greater)
Involved Region or Country
North America, Middle East, Israel, Palestine, Chile, Paraguay and Thailand.
Additional Options
Crew Cab and Extended Cab Models ONLY
Copyright 2023 General Motors LLC. All Rights Reserved.
Page 2
August, 2023
Bulletin No.: 20-NA-175
Condition
5645798
Some customers may comment on noticing anywhere from 2 –10 mm (0.08 – 0.4 in.)
vertical misalignment of the body feature line between the cab and the pickup box, on the
driver's side of vehicle.
Cause
The cause of the condition may be pickup box structure variation.
Correction
Realign the left side of the cab and install shim washers, following the steps in the
Service Procedure below.
Service Procedure
Important: Service agents must comply with all
International, Federal, State, Provincial, and/or
Local laws applicable to the activities it performs
under this bulletin, including but not limited to
handling, deploying, preparing, classifying,
packaging, marking, labeling, and shipping
dangerous goods. In the event of a conflict between
the procedures set forth in this bulletin and the
laws that apply to your dealership, you must follow
those applicable laws.
1. Verify the condition by visually checking, and
measuring, the body feature line variance, on the
left side of the vehicle.
2. Raise and support the vehicle. Refer to Lifting and
Jacking the Vehicle in SI.
5645799
5645804
Bulletin No.: 20-NA-175
August, 2023
Page 3
Important: We should never install more than 2 shim
washers in the rear to make the alignment, one will get
roughly 5 mm at the box/cab and two will get roughly
10 mm at box/cab interface.
6. Remove the jack stand from the cab.
5645800
3. Remove the 3 left side body mount bolts and
washers (1).
5645799
7. Perform the following procedure before installing
the body mount bolts (1).
7.1. Remove all traces of any of the original
adhesive patch from the bolt threads.
7.2. Clean the threads of the bolts with denatured
alcohol, or equivalent, and allow to dry.
7.3. Apply Threadlocker to the body mount bolts.
5645802
Note: For trucks with running boards, the jack can be
positioned below the running board bracket. For trucks
without running boards, position the jack below the cab
pinch weld and use a wood block to protect the paint,
and sheet metal.
4. Using a jack stand (1), raise the cab high enough
to achieve enough clearance to install the shim
washers between the body of the truck and the top
of each body mount.
5. Install shim washers to each body mount
location(s) as needed.
Note: Typically it will take 2 shim washers in the rear
mount to get a 10 mm adjustment in height at the body
line. If more than one washer shim is installed on the
rear body mount, you will need to put a single shim
washer on the mount at the B-Pillar.
5645806
8. Re-torque the 3 left side body mount bolts.
Tighten.
Tighten the bolts to 165 Nm (122 lb ft).
9. Remove the support and lower the vehicle.
10. Verify that the cab alignment condition has been
eliminated.
Page 4
August, 2023
Bulletin No.: 20-NA-175
Parts Information
Causal
Part
N/A
Description
Part
Number
Shim
84642724
Threadlocker
12345382
(U.S.)
10953489
(Canada)
Qty
As needed
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. Submit the cost of the
required washers as “Net Item Miscellaneous”.
Labor Operation
Description
Labor Time
1481418*
Realign Left Side of Cab to Pickup Box, Install Shim Washers
0.6 hr.
*This is a unique Labor Operation for Bulletin use only.
Version
5
Modified
Released - September 02, 2020
Revised October 27, 2020 – Removed Date Breakpoint
Revised December 21, 2020 – Added 2021 Model Year to Silverado/Sierra 1500.
Revised May 09, 2022 — Updated Shim Part number and Added 2022 Model Year.
Revised July 27, 2023 — Added 2023 and 2024 Model Years.
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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