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Service bulletins for the 2020 Western Star 5700

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

159 on file from NHTSA, as of 2026-10-19.

By type

By component

Only bulletins with component: Transmission and driveline are shown. Show all

Bulletins, newest first
TSB26-008-WST2025-05-02. Service bulletin. POWER TRAIN. Service Solution for DT12 Oil Plug Ports
CXA 06_24_Clutch Bolts2024-07-09. Other. POWER TRAIN. CX Advocate communication for clutch bolts
TSB35-023-WST2024-06-05. Service bulletin. POWER TRAIN. Technical Service Bulletin for New Final Drive Over Heat Diagnostic
ICI22-0172022-05-03. Service bulletin. POWER TRAIN. Important Campaign Information Letter for DDC D21M1 Termination Date Extended. This letter is to inform you that a revised bulletin for Detroit Diesel Field Service Campaign D21M1, DT12 Transmission Drive Shaft Cover Plug Reseal has been EXTENDED for an additional three months. Please use the extended termination date for all work under D21M1 from this point forward. REVISION: D21M1 termination date extended to July 1, 2022.
SBW41-0022022-02-05. Service bulletin. POWER TRAIN. Revised Western Star Service Bulletin for Drive Line Vibration. Minor note: added an update of document previously submitted. The related VMRS codes are added
WSTCAE171-20192021-05-18. Service bulletin. EQUIPMENT; FUEL SYSTEM, OTHER; POWER TRAIN. Allison FuelSense 2.0
SS701-WST20212021-05-01. Service bulletin. POWER TRAIN. Service Solution for DT12 Harness Chaffing - PT Can Faults. Transmission will not shift into Gear while driving or will not start and trigger multiple PT CAN Fault Codes.
D21M12021-05-01. Service bulletin. POWER TRAIN. Detroit Field Service Campaign for DT12 Transmission Drive Shaft Cover Plug Reseal. Daimler Trucks North America LLC, on behalf of its DETROIT Powertrain Division, is initiating Field Service Campaign D21M1 on certain DT12 transmissions in order to reseal the bypass plugs of the drive shaft cover located in front housing.
DT12 Trans Chafe2021-04-08. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; POWER TRAIN. DTNA received a field notification on multiple units regarding diagnostic fault codes that were found to be causing issues to the After Treatment Control Module (ACM). These fault codes indicated that the ACM communication message was not received by the Motor Control Module (MCM) which in certain cases, led to a 25% engine de-rate situation. Further diagnosis revealed that the DT12 wiring harness was chafing and contacting the transmission TCU case. To reduce potential chafing areas, the proposed short-term containment was to route the wiring harness using additional tie straps. This communication applies to Freightliner and Western Star vehicles built with DT12 transmissions.
D21M32021-03-31. Service bulletin. POWER TRAIN. Detroit Field Service Campaign for DT12 Gear Grind During Downshift Software Update.
WI21-0042021-03-02. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. Warranty Information Letter for Detroit Resources: Exploded View DD Platform and DT12 Posters. Detroit's TechComm team created visual aids for the network and released exploded view posters for DD platform engines. In early 2021, Detroit added multiple DT12 posters.
SBW35-0182020-12-30. Service bulletin. POWER TRAIN. Western Star Service Bulletin for Axle Flange Gasket Replaced with O-Ring. Daimler Trucks North America has released a new axle shaft to hub rubber O-ring (part number 11-30728-000) as a replacement for the paper gasket (part number 11-14418-000). The new O-ring will provide better sealing and is reusable. It is quicker and easier to use compared to the paper gasket, because using a paper gasket requires cleaning the hub when the axle shaft is removed.
WP20-018R2020-12-12. Service bulletin. STEERING; POWER TRAIN. Revised Warranty Policy Letter for Alliance/Mascot Aftermarket Warranty and Claim Filing. Revisions are in blue. With Mascot now in partnership with Detroit Reman and Alliance Parts, DTNA is pleased to announce that Mascot coverage has been added to OWL. Remanufactured Alliance/Mascot parts include transmission, differential, steering gear, and steering pump used in an on-highway vehicle applications. The Alliance/Mascot aftermarket warranty coverage period has not changed: depending on the part, coverage is for one (1) or two (2) years and current parts, labor, and reimbursement policies apply.
WP20-0182020-12-12. Service bulletin. STEERING; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; POWER TRAIN. Warranty Policy Letter for Alliance/Mascot Aftermarket Warranty and Claim Filing. With Mascot now in partnership with Detroit Reman and Alliance Parts, DTNA is pleased to announce that Mascot coverage has been added to OWL. Remanufactured Alliance/Mascot parts include transmission, differential, steering gear, and steering pump used in an on-highway vehicle applications. The Alliance/Mascot aftermarket warranty coverage period has not changed: depending on the part, coverage is for one (1) or two (2) years and current parts, labor, and reimbursement policies apply.
SBW26-0052020-12-07. Service bulletin. POWER TRAIN. Revised Western Star Service Bulletin forDT12 PTO Upfit. This bulletin replaces the version dated 09/23/2019. DDCSN and Power Service Literature references have been removed.
D20M22020-11-04. Service bulletin. POWER TRAIN; EQUIPMENT; ENGINE AND ENGINE COOLING. Detroit Diesel Field Service Campaign for DETROIT TM2020 Transmission Replacement. It has been discovered that certain TM2020 units have porosity issues in and around the oil cooler line fittings on the center housing.
20TS-072020-10-21. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ENGINE AND ENGINE COOLING. Technical Service Letter for Cold Weather Faults on GHG17/21 DD13 with MCM Software Version 14. Due to colder weather, there may be an increase in the frequency of faults, noted below, on GHG17/21 DD13 trucks built after June 5th 2019. This is due to a calibration issue in the current MCM software (14.1.1.5 or 14.2.1.3). New software is scheduled for release in the first quarter of 2021 that will address these faults.
17TS-05REV22020-10-21. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM:SOFTWARE. Revised Technical Service Letter for Detroit DT12 TCM GHG17 Only; Bootloader Update. On Detroit DT12 equipped vehicles, it may be necessary to complete an additional step in the programming process when updating the TCM software.
SBW26-0042020-08-29. Service bulletin. POWER TRAIN; EQUIPMENT. Western Star Service Bulletin for DT12 Transmission Cooler Retrofit.
SBW41-0022020-03-03. Service bulletin. POWER TRAIN. Service Bulletin for Midship Bearing Replacement for built vehicles with driveshafts SPL140, SPL170 or SPL250 with first order driveline vibration. This version replaces bulletin from 12/19/19.
WP20-001REV2020-02-15. Service bulletin. POWER TRAIN; LANE DEPARTURE; SUSPENSION; EQUIPMENT. Revision to a Warranty Policy Letter announcing the One Stop Supplier Extended Program Launch. The One Stop Supplier Extended Program streamlines the claim filing process because with One Stop Supplier Extended, the service network will file claims for some supplier-supported coverages in OWL. Revisions are in blue.
WP20-0012020-01-21. Service bulletin. UNKNOWN OR OTHER; POWER TRAIN; SUSPENSION; LANE DEPARTURE. Warranty Policy Letter announcing the One Stop Supplier Extended Program Launch. The One Stop Supplier Extended Program streamlines the claim filing process because with One Stop Supplier Extended, the service network will file claims for some supplier-supported extended coverages in OWL.
SBW41-0022019-12-20. Service bulletin. POWER TRAIN. Service Bulletin for Midship Bearing Replacement for built vehicles with driveshafts SPL140, SPL170 or SPL250 with first order driveline vibration.
SS10345772019-12-03. Service bulletin. EQUIPMENT; POWER TRAIN; STRUCTURE; EQUIPMENT ADAPTIVE/MOBILITY. Service Solution to address WST Cab drone / vibration / tapping Under acceleration for vehicles w/Eaton Manual Trans.
SB35-0162019-09-28. Service bulletin. POWER TRAIN. Service Bulletin for Hub Oil Level in Final Drive (NFD) Top Performance Axles on Decked Vehicles

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.