How much fluid does a 2006 F150 rear diff hold?
Approximately 3 quarts of gear oil, though exact capacity depends on the rear axle type (8.8-inch or 9.75-inch) and whether a limited-slip differential is installed. For precision, check the vehicle’s VIN-specific service data or the owner's manual.
Understanding the 2006 F-150 rear differential options
In 2006, Ford offered two rear-axle configurations for the F-150: the common 8.8-inch differential and the larger 9.75-inch unit used on certain trims and configurations. The oil capacity varies slightly between these housings and can be affected by a limited-slip differential or gearing. The recommended gear oil is typically GL-5 with a viscosity such as 75W-90 or 80W-90, depending on the exact axle specification.
Typical capacity by axle type
Below are typical capacity ranges you might encounter on the 2006 F-150, based on widely cited factory specs and service guides. Actual capacity for your truck may vary by axle code and differential type. Use the fill plug to determine exact fill level after draining and refilling.
- 8.8-inch rear axle: approximately 2.9–3.0 quarts (about 2.8–2.9 liters) when filled to the standard level.
- 9.75-inch rear axle: approximately 2.7–3.0 quarts (about 2.6–2.8 liters), depending on gearing and whether a limited-slip differential is present.
Note: These figures assume you are refilling to the recommended level via the fill plug and using the correct gear oil. If the differential includes a clutch-type limited-slip or a different lubrication path, you may need to adjust the fill amount slightly. Always verify by filling until fluid just begins to seep from the fill hole, with the vehicle level on a flat surface.
Practical guidance for replacing rear-diff fluid
When performing a fluid change, keep these steps in mind to ensure accurate measurement and proper service life:
- Drain the old fluid completely and inspect the fluid for metal shavings or discoloration, which can indicate wear or internal issues.
- Reinstall the drain plug with a new gasket and torque to the manufacturer’s specification.
- Refill through the fill plug with the recommended gear oil, typically 75W-90 GL-5 or 80W-90, depending on the axle code.
- Fill until the fluid begins to seep from the fill hole, then reinstall the fill plug and wipe away any excess.
- For limited-slip differentials, add the appropriate friction modifier per Ford’s instructions and ensure the level remains correct after a short drive and recheck.
It’s a good practice to verify the exact axle code on your F-150’s door jamb sticker or under the hood label to match the service data. If you’re unsure, contact a Ford dealer with your VIN to obtain the precise axle capacity and oil specification.
Summary
The rear differential on a 2006 Ford F-150 typically holds about 3 quarts of gear oil, with slight variations depending on whether the truck uses an 8.8-inch or a 9.75-inch axle and whether a limited-slip differential is present. For the most accurate figure, consult the vehicle’s axle code, VIN-specific service data, or the owner’s manual, and fill with the recommended gear oil to the specified level.
