2021 Oshkosh S-Series problems, complaints & recalls
Safety recalls (7)
Electrical System:alternator/Generator/Regulator 2022-05-26 · campaign 22V378000 · 1,316 vehicles
Defect: Oshkosh Corporation (Oshkosh) is recalling certain 2019-2022 S-Series 2.0 Concrete Mixers. Incorrectly installed alternator electrical cable clamps may rub against the vehicle frame or hydraulic hose, possibly damaging the alternator cables.
Risk: Damaged alternator electrical cables can increase the risk of a fire.
Fix: Oshkosh will provide instructions on how to inspect the wiring, reposition the clamps, and properly secure the cables. The repair can be performed by the owner or an Oshkosh service center, free of charge. Owner notification letters were mailed on June 23, 2022. Owners may contact Oshkosh's customer service at 1-888-686-7278.
Fuel System, Diesel:fuel Injection System:fuel Rail 2022-01-11 · campaign 22V008000 · 1,608 vehicles
Defect: Oshkosh Corporation (Oshkosh) is recalling certain 2019-2022 S-Series vehicles. The fuel tubes between the fuel rail and the injector for cylinders 4, 5 and 6 may be susceptible to cracking, resulting in a high pressure fuel leak.
Risk: A high pressure fuel leak in the presence of an ignition source may increase the risk of a fire.
Fix: On engines with 75 miles or less, dealers will install vibration isolators to the fuel tubes. Engines with more than 75 miles will receive new fuel tubes with vibration isolators. Repairs will be performed free of charge. Owner notification letters are expected to be mailed February 1, 2022. Owners may contact Oshkosh customer service at 1-8088-686-7278.
Suspension:multiple Axle 2022-01-11 · campaign 22V009000 · 1,268 vehicles
Defect: Oshkosh Corporation (Oshkosh) is recalling certain 2019-2022 S-Series vehicles. The u-bolts securing the front axle may fail.
Risk: Bolt failure may allow the front axle to shift or detach, increasing the risk of a crash.
Fix: Oshkosh will provide new u-bolts, free of charge. Owner notification letters were mailed February 24, 2022. Owners may contact Oshkosh customer service at 1-888-686-7278.
Steering:hydraulic Power Assist:pump 2021-11-02 · campaign 21V851000 · 697 vehicles
Defect: Oshkosh Corporation (Oshkosh) is recalling certain 2020-2021 S-Series vehicles. A machining defect may cause pressure to build in the power steering pump and break the shaft seal, resulting in a loss of power steering assist.
Risk: A loss of power steering assist increases the risk of a crash.
Fix: Owners will inspect and replace the power steering pump as necessary. Owners may perform this work themselves or reach out to one of our service centers to perform the inspection and repair work free of charge. Owner notification letters were mailed on December 15, 2021. Owners may contact Oshkosh customer service at 1-888-686-7278.
Electrical System:wiring:fuses And Circuit Breakers 2021-06-27 · campaign 21V482000 · 897 vehicles
Defect: Oshkosh Corporation (Oshkosh) is recalling certain 2019-2022 S-Series vehicles. These vehicles were manufactured with 10 amp Anti-Lock Brake System (ABS) fuses, instead of the required 15 amp ABS fuses.
Risk: The incorrectly sized fuse may blow during an ABS braking event, increasing the risk of a crash.
Fix: Oshkosh will provide owners new fuses, a new fuse label, and installation instructions, free of charge. Owner notification letters were mailed on July 29, 2021. Owners may contact Oshkosh customer service at 1-888-686-7278.
Suspension:multiple Axle 2021-05-06 · campaign 21V322000 · 47 vehicles
Defect: Oshkosh Corporation (Oshkosh) is recalling certain 2021 S-Series vehicles. The auxiliary axles may not have been properly secured and may detach.
Risk: A detached axle may cause a loss of vehicle control, increasing the risk of a crash.
Fix: A technician will inspect and, as necessary, replace any improperly installed fasteners, free of charge. Owner notification letters were mailed on May 26, 2021. Owners may contact Oshkosh customer services at 1-888-686-7278.
Power Train:automatic Transmission:internal:shaft:output 2021-02-26 · campaign 21V125000 · 19 vehicles
Defect: Oshkosh Corporation (Oshkosh) is recalling certain 2020-2021 S-Series vehicles. The rear axle output shaft may not have been heat-treated properly, which could cause the shaft to fracture.
Risk: A fractured rear output shaft may cause the shaft or interaxle driveline to detach from the vehicle, increasing the risk of a crash or injury.
Fix: Oshkosh will notify owners, and owners will be instructed to inspect the output shaft, and if necessary, order a new one and replace it, free of charge. The recall began on March 31, 2021. Owners may contact Oshkosh customer service at 1-888-686-7278.
Service bulletins (30)
Technical service bulletins are repair instructions manufacturers send dealers for known issues. Unlike recalls, the fix is not automatically free — but naming the bulletin at the service desk can save diagnosis time and support goodwill repairs.
Unknown Or Other 2026-09-03 · FDM-SVC-051 · Service Bulletin/Repair Instructions
this bulletin provides instructions for the inspection, weld repair, and installation of reinforcement brackets on the exhaust mast of oshkosh 2.0 s-series trucks.
Unknown Or Other 2026-09-03 · FDM-SVC-050 · Service Bulletin/Repair Instructions
this bulletin provides instructions for the inspection, weld repair, and installation of reinforcement brackets on the exhaust mast of oshkosh 2.0 s-series trucks.
Unknown Or Other 2026-08-18 · FDM-IB-016 · Other
this bulletin provides instructions for identifying and locating all driveline grease zerk fittings. lubrication of the driveline is important for proper vehicle operation.
Electrical System 2026-05-13 · FDM-SVC-045 · Other
this bulletin provides instructions to install the latest battery disconnect switch on s-series 2.0 vehicles in serial number range 788727 - 814085.
Unknown Or Other 2026-03-25 · FDM-SVC-044 · Other
this bulletin provides instructions to install a check valve in the chute return hydraulic circuit to prevent fluid back flow through the chute manifold if a chute up or down hose fails, and install a shut-off valve on the fan manifold to turn off flow of hydraulic oil to the chutes and water pump.
Unknown Or Other 2026-03-01 · FDM-IB-013 · Other
this bulletin provides instruction for replacing the existing chute drive washer with a hardened steel washer. this change prolongs the service life of the drive sprocket and chute operation.
Showing the 6 most recent of 30 bulletins. Search all of them free at nhtsa.gov.
What owners report
No detailed complaint narratives on file.
Excerpts of consumer complaints filed with NHTSA, lightly truncated. They are owner statements, not verified findings.