23-NA-048

Bulletin No.:
Service Bulletin
Date:
23-NA-048
February, 2024
TECHNICAL
Subject:
Brand:
Oil Leak from Center of Vehicle
Model:
Silverado 1500 LTD (RPO J21, VIN
Digit 5 = W/Y)
Chevrolet
Silverado 1500 New (RPO J22,
VIN Digit 5 = A/D)
Silverado 1500
Sierra 1500 Limited (RPO J21,
VIN Digit 5 = 8/9)
GMC
Sierra 1500 - New
(RPO J22, VIN
Digit 5 = H/U)
Sierra 1500
Model Year:
from
to
2022
2022
2023
2023
2022
2022
2023
2023
VIN:
from
to
Engine:
Transmission:
L3B
Involved Region or Country
North America
Condition
Some customers may comment that an oil leak can be seen coming from the center of
vehicle
Some technicians may find oil leaking from the bell-housing area.
Cause
This condition may be caused by oil leaking past the rear crankshaft oil seal.
Correction
If the oil leak has been verified to be coming from the rear crankshaft seal, replace the
rear crankshaft oil seal and housing.
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.
Copyright 2024 General Motors LLC. All Rights Reserved.
Page 2
February, 2024
Service Procedure
Bulletin No.: 23-NA-048
Refer to Crankshaft Rear Oil Seal and Housing
Replacement in the Service Manual.
Parts Information
Note: Only use the parts the coincides with the repair
performed.
Causal
Part
Description
Part
Number
Qty
X
HOUSING, CR/
SHF RR
OIL SEAL
12731559
1
N/A
BOLT, A/TRNS
FLEX PLT
11548684
8
N/A
GASKET, EXH
SYS FRT
84407373
1
N/A
BOLT, RR S/ABS
LWR BRKT
11561300
1
N/A
GASKET, O/PMP
SUC PIPE
55487654
1
N/A
GASKET, TRFER
CASE ADAP
24245110
1
N/A
BOOT, TRFER
CASE FRT
OUTPUT SHF
84124171
1
SEAL, TRNS
CLR PIPE
85628205
1
Refer
to EPC
As Required
N/A
N/A
OIL, ENGINE
N/A
SEALANT, RTV
1
6538223
Important: To reduce rolling of the crankshaft seal. It is
recommended to utilize the J-8608 and J-8092, to fully
seat the seal onto the crankshaft before tightening the
bolts to the housing. Only using hand pressure, press
the seal protector/installer on the end of the crankshaft.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation
Description
Labor Time
4066250
Crankshaft Rear Oil Seal Housing Replacement
Use the Published Labor
Operations Time
Version
4
Modified
Released March 30, 2023
Revised May 04, 2023 - Update Labor Operation Number.
Revised June 07, 2023 - Update Trans Case Adapter Gasket Part Number.
Revised February 22, 2024 - Update Service Procedure section.
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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