Service bulletins for the 2021 Western Star 4700
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.
108 on file from NHTSA, as of 2026-10-19.
| WI24-019 | 2024-12-04. ENGINE. Warranty Information letter for Detroit Line or Line Seal, High Pressure Fuel Injector Standard Repair Time Updates |
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A warranty extension may pay for a repair after the basic warranty has ended. Read the document for which vehicles and which repair it covers.
By type
By component
| PB-47-900-WST | 2026-07-06. Service bulletin. FUEL/PROPULSION SYSTEM. Parts Bulletin for Fluorosilicone Fuel Tank Cap Seals |
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| CXA 03_26_Surge Tank | 2026-04-02. Other. ENGINE. CX Advocate for discolored coolant surge tanks (24CSA-20) |
| TSB-32-020-WST | 2026-03-27. Service bulletin. SUSPENSION. Technical Service Bulletin for TufTrac M12 Bolts |
| CXA_10_25_Conmet Oil Pan | 2025-11-05. Other. ENGINE. CX Advocate for ConMet Oil Pan Insert Additional Issues |
| 24CSA-19Rev | 2025-09-02. Other. ENGINE. Revised Customer Service Annoucement for No Trouble Found Heavy Duty Engine Product (HDEP) Oil Separator Leaks |
| PB33-005-WST | 2025-07-08. Service bulletin. STEERING. Parts Bulletin for Tie Rod Assembly Part Breakdown |
| CXA 3_25_NOx | 2025-04-02. Other. ENGINE. CX Advocate for NOx conversion low faults |
| CXA 2_25_NOx | 2025-03-04. Other. ENGINE. CX Advocate for NOx conversion low faults |
| SS778-WST | 2025-01-29. Other. STEERING. Service Solution for Power Steering Reservoir Fill Cap Venting |
| CXA 1_16_NOx | 2025-01-29. Other. ENGINE. CX Advocate for NOx conversion low faults |
| WI24-019 | 2024-12-04. Warranty extension. ENGINE. Warranty Information letter for Detroit Line or Line Seal, High Pressure Fuel Injector Standard Repair Time Updates |
| SS1023366-Detroit | 2024-11-06. Other. ENGINE. Service Solution for Detroit Successful Regen Reference for GHG17 DD Engines |
| 24CSA-20 | 2024-11-06. Service bulletin. ENGINE. Customer Service Annoucement for Discolored Coolant Surge Tank on Heavy Duty Engine Product (HDEP) |
| 24CSA-19 | 2024-11-06. Other. ENGINE. Customer Service Annoucement for Heavy-Duty Engine Product (HDEP) Oil Separator Leaks |
| SS1023366-Detroit | 2024-10-04. Other. ENGINE. Service Solution for Detroit Successful Regen Reference for GHG17 DD Engines |
| CXA 8_24_Conmet Oil Pan | 2024-09-07. Other. ENGINE. CX Advocate for ConMet Oil Pan Insert Additional Failures |
| CXA 7_24_NOx | 2024-08-02. Other. ENGINE. CX Advocate for NOx conversion low faults. Update to CXA 6_24_NOx submission. |
| CXA 7_24_Conmet Oil Pan | 2024-08-02. Other. ENGINE. CX Advocate for ConMet Oil Pan Insert Additional Failures |
| CXA 06_24_Clutch Bolts | 2024-07-09. Other. POWER TRAIN. CX Advocate communication for clutch bolts |
| CXA 06_24_NOx | 2024-07-09. Other. ENGINE. CX Advocate communication for NOx conversion low faults |
| VSWP Customer Letter | 2024-06-22. Other. ENGINE. Customer letter regarding variable speed water pump. |
| SS734-WST | 2024-06-05. Other. SUSPENSION. Service Solution for Thread Spring Pin Suspension Alignment & Installation |
| SS763-WST | 2024-06-05. Other. ENGINE. Service Solution for DEF Pump Wiring for Cummins CM2450 Engine Controller |
| TSB35-023-WST | 2024-06-05. Service bulletin. POWER TRAIN. Technical Service Bulletin for New Final Drive Over Heat Diagnostic |
| SS3144-FTL | 2024-05-07. Service bulletin. ENGINE AND ENGINE COOLING. Service Solution for DEF Pump Wiring for Cummins CM2450 Engine Controller |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.