Recall 21V851 affects 697 2020-2021 Oshkosh S-Series vehicles for a power steering pump defect. Inspection and repair are free through Oshkosh service centers.
Oshkosh is recalling 697 2020-2021 S-Series vehicles because a machining defect can let pressure build in the power steering pump and break the shaft seal. That failure can remove power steering assist and increase crash risk, and Oshkosh dealers will complete the recall repair free of charge.
Does this recall apply to your specific vehicle?
The official, free per-VIN recall check is run by NHTSA. Enter your VIN and we'll forward you directly — and add you to a free watchlist so you hear about new recalls for your vehicle.
Check my VIN at NHTSARecallNotify doesn't check your VIN — NHTSA's official tool does. We use your email only to alert you to new recalls.
Watch this vehicle for recalls
Add it to your free watchlist and we will alert you as new federal recalls are posted for your year, make and model. New-recall alerts are rolling out now.
You are on the watchlist.
We will email you as new federal recalls are posted for your vehicle.
What's wrong?
The power steering pump on 2020-2021 Oshkosh S-Series trucks supplies hydraulic pressure for steering assist. That pressure helps the steering gear turn the front wheels with less driver effort, especially at low speed or while maneuvering a loaded truck. The pump depends on an internal rotor and shaft seal staying within specification so hydraulic oil stays where it belongs.
On affected trucks, a machining defect left the internal pump rotor outside the required flatness specification. That uneven rotor can let pressure build inside the pump and break the shaft seal. Once the seal fails, hydraulic power steering oil can move out of the steering system and into the engine oil, and the truck can lose power steering assist.
What you notice can start with fluid levels. An overfull engine oil reading, low hydraulic oil in the steering tank, or higher steering effort are warning signs that the pump shaft seal or steering pump has failed.
Who's affected?
Covers the 2020 and 2021 model years with the same power steering pump issue listed for both.
| 2021 Oshkosh S-Series | power steering system |
|---|---|
| 2020 Oshkosh S-Series | power steering system |
| Units affected | 697 |
| Field incidents | NHTSA has logged 2 field incidents to date. |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether your specific truck is included.
What's the safety risk?
Loss of power steering assist makes the S-Series harder to steer and increases the risk of a crash. Warning signs include engine oil over full, low hydraulic oil in the tank, or higher steering effort, which points to a failed steering pump. Schedule the inspection and repair soon. Repair is free at any franchised Oshkosh dealer.
What should I do?
- Check your VIN to confirm your 2020-2021 Oshkosh S-Series is included in this recall.
- Contact an Oshkosh service center to schedule the free power steering pump inspection and replacement if needed, which addresses loss of power steering assist.
- Bring the recall notice if Oshkosh mailed one. If not, reference recall number 21V851 when you call.
- Stop driving and contact the service center if steering assist is lost before the inspection or repair.
What happens at the repair
At an Oshkosh service center, an Oshkosh technician checks the power steering pump against the affected serial number list, inspects the pump, and replaces any suspect pump found. Owners can also perform the inspection and pump replacement themselves using Oshkosh instructions. Replacement parts are provided at no cost, and the service center inspection and repair are free under the recall.
Timeline
| November 2, 2021 | NHTSA published the recall |
|---|---|
| December 13, 2021 | Owner notification mailed |
| December 13, 2021 | VIN-searchable in NHTSA's database — Check your VIN to see whether this recall applies to your specific vehicle. |
| December 13, 2021 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 21V851?
Recall 21V851 covers 697 2020-2021 Oshkosh S-Series vehicles with a machining defect in the power steering pump. Pressure can build in the pump, break the shaft seal, and cause loss of power steering assist, increasing crash risk. Oshkosh service centers inspect and repair it free.
What should I do if my 2020-2021 Oshkosh S-Series is on this recall?
Check your VIN to confirm your specific vehicle is included in recall 21V851. If it is, inspect the power steering pump or call Oshkosh customer service at 1-888-686-7278 for a service center inspection and repair. The service center repair is free.
Is the recall repair free?
Yes. Federal recall law requires manufacturers to repair recall defects at no cost. Oshkosh says owners can perform the inspection themselves or contact one of its service centers to perform the inspection and power steering pump repair free of charge.
What is the safety risk?
The safety risk is loss of power steering assist. If the power steering pump shaft seal breaks, steering effort increases and crash risk rises. If your VIN is included, arrange the inspection and repair through Oshkosh before continuing regular service use.
When did Oshkosh notify owners?
Oshkosh mailed owner notification letters on December 15, 2021. If you bought the vehicle used or never received the letter, the VIN still decides whether recall 21V851 applies. Check your VIN, then reference recall 21V851 when you contact Oshkosh or a service center.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/21V851000 |
|---|---|
| Oshkosh customer service | 1-888-686-7278 |
| NHTSA recall # | 21V851 |
| NHTSA recall # (full) | 21V851000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Recall Investigation Document (PDF) (PDF)
- Download Recall Report (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 20, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →