The rear axle in a Ford F-450 Super Duty is a heavy-duty unit designed to handle substantial towing and payloads. In most dual-rear-wheel (DRW) configurations, the common setup is a Dana Spicer heavy-duty rear axle with an 11.5-inch ring gear, though exact sizes can vary by model year and option. Confirm the specific axle by checking the axle tag or the vehicle’s build data.
Overview of the axle family
Ford’s F-450 has spanned several generations, and the rear axle has evolved accordingly. Across these years, the truck has largely relied on a robust rear-axle assembly produced by Dana Spicer (with Meritor involvement on some early configurations). The design is intended to deliver high load capacity for both towing and payloads, especially in dual-rear-wheel setups.
Common rear axle sizes used in F-450s
Because the F-450 has varied by model year and wheel configuration, the most frequently seen rear-axle ring-gear sizes include 11.5 inches on modern DRW configurations, with older builds occasionally using 10.5 inches or 9.75 inches in certain trims or eras.
- 11.5-inch ring gear (common on modern DRW F-450s; heavy-duty Dana Spicer axle)
- 10.5-inch ring gear (found on some earlier configurations or specific trims)
- 9.75-inch ring gear (less common on F-450; more typical in some older heavy-duty variants)
Identifying the axle size helps when ordering parts or performing maintenance; the exact axle depends on year, drivetrain, and options.
How to verify your F-450’s rear axle
To confirm the exact rear axle on a given F-450, use the following methods:
- Inspect the axle tag or stamping on the differential housing for the ring-gear size and ratio code.
- Reference the vehicle’s build sheet or door jamb VIN sticker to see the axle specification from the factory.
- Compare the differential model number stamped on the axle to manufacturer catalogs (Dana Spicer or Meritor) to confirm the exact axle family.
Once you identify the axle size and code, you’ll know which replacement parts and lubrication specifications apply, and you can plan maintenance accordingly.
Decoding axle codes
Axle codes can vary by year and supplier, but common clues include ring-gear sizes (11.5", 10.5", 9.75"), axle family codes (such as Spicer S110 for 11.5"), and lubrication specifications. Your best reference is the build sheet or the axle tag.
Summary
The Ford F-450’s rear axle is a heavy-duty assembly, most often an 11.5-inch ring-gear Dana Spicer unit on modern DRW models, with variations across generations including 10.5" and 9.75" sizes in other configurations. To be certain, verify the exact axle by checking the axle tag, VIN/build sheet, or the differential model number.