2020 Peterbilt 337 technical service bulletins

Bulletins tell dealers how to fix known problems. A warranty extension means the manufacturer pays for that repair for longer.

• Sep 11, 2026 Service bulletinKenworth: Dealers should check the chassis list and SIR weekly for VIN changes
• Aug 13, 2026 Service bulletinThe verbiage in the Introduction section has been updated.
• Nov 22, 2024 Service bulletinInfo Only Unnecessary starter replacements can result from customer complaints regarding engine starting...
• Jul 30, 2024 Service bulletinFix As Fail The height control valve (HCV) rod on vehicles with low air leaf suspensions is prone to...
• Feb 10, 2023 Service bulletinFix As Fail – Chassis that were manufactured with certain battery cable routing brackets may experience...
• Oct 18, 2022 Service bulletinInfo Only
• Sep 9, 2022 Service bulletinFix-As-Fail On certain chassis with Low Air Leaf Suspension or Low-Low Air Leaf Suspension, the Height...
• Aug 3, 2022 Service bulletinThe service information for Bendix Air Dryer maintenance is being updated to include new procedures.
• Mar 3, 2022 Service bulletinFix-As-Fail – A hill start assist (HSA) valve plumbing revision eliminates ice buildup in the HSA valve...
• Feb 4, 2022 Service bulletinDue to major data carriers phasing out 3G networks, chassis currently utilizing first generation Peoplenet...
• Sep 21, 2021 Service bulletinFix-As-Fail – Due to undersupply issues, only a limited supply of Diesel Exhaust Fluid (DEF) sensors are...
• Sep 20, 2021 Service bulletinInformation Only
• Jul 19, 2021 Service bulletinFix-as-Fail: Radio does not mute when truck with auto trans is placed in reverse
• Jun 22, 2021 Service bulletinSafety Recall – Cummins Fuel Rail Leak – the federal safety agency ID: 21V391 / TC: 2021-323, Cummins...
• Feb 10, 2021 Service bulletinInformation Only – Windshield washer pumps have a high No Trouble Found rate
• Oct 1, 2020 Service bulletinFix as Fail: Peterbilt has introduced an improved mounting bracket for low mount air tanks for vehicles...
• Sep 25, 2020 Service bulletinInformation only: In 2020, Peterbilt and Kenworth began using the same M10, M12, M16, and M20 frame...
• Jul 29, 2020 Service bulletinFix-As-Fail
• Jun 10, 2020 Service bulletinFix as Fail: For all conventional models, except 387/587, equipped with Side-of-Cab (“SOC”) exhaust and...
• Jun 8, 2020 Service bulletinInformation Only:
• May 29, 2020 Service bulletinInformation only: Hendrickson Softek front axle maintenance intervals and requirements.
• Mar 17, 2020 Service bulletinInformation Only: Proper jump-starting voltage will eliminate high voltage related issues and equipment...
• Dec 18, 2019 Service bulletinInformation Only
• Nov 6, 2019 Service bulletinInformation Only:
• Sep 27, 2019 Service bulletinInformation Only –
• Sep 6, 2019 Service bulletinInformation: Chassis built after 01/11/2016 with hydraulic brakes were provided with a jumper harness in...
• Aug 30, 2019 Service bulletinSafety Recall: Defectective lower hsaft to u-joint yoke in non-telescoping steering columns due to...
• Aug 28, 2019 Service bulletinFix-As-Fail -“ Composite fittings used in the cooling system may crack, resulting in coolant leaks
• Aug 23, 2019 Service bulletinFix-As-Fail: Two separate causes have been identified as root
• Jul 13, 2016 Service bulletinSmartNav 2.0 Hardware retrofit for quality validation and vehicle validation units.