How do I know what Ford rear axle I have?
The quickest way is to locate the axle’s model code or tag on the differential housing and cross‑reference it with Ford’s axle code charts or your vehicle’s VIN data to confirm the exact model and gear ratio.
Understanding which Ford rear axle you have matters for parts compatibility, gearing decisions, and maintenance. This guide walks you through where to look for identifying markings, how to interpret them, and what common Ford axles you’re likely to encounter on modern and classic vehicles.
Where to look for markings
Ford axles typically carry identifying markings in a few reliable places. If you don’t see a tag right away, keep an eye for stamped numbers on the housing or a small badge attached to the axle.
- Axle tag on the housing: A metal tag or stamped label near the differential often lists the model and gear ratio.
- Differential cover or stamping: Some codes are stamped into the cover or into the casting near the fill plug.
- Axle tube stamping: In some cases, codes are pressed into the axle tubes near the perches or on the end of the housing.
- VIN/build sheet or dealer data: If you have the vehicle’s VIN or build sheet, it can reveal the original axle specification, sometimes via a Ford decoder or the dealer’s records.
Interpreting these markings is the first step. If you find a code, write it down exactly as it appears and plan to look it up in Ford’s catalogs or a trusted axle-code database. If markings are absent, you’ll move to measurements and deeper verification.
Common Ford rear axles you may encounter
Several rear axles show up frequently across Ford cars and trucks. This quick guide helps you orient what you’re likely looking at when you find markings.
- 8.8-inch rear axle: A current, widely used Ford axle found in many late 1980s–present vehicles, with strong aftermarket support and various gear options.
- 9-inch rear axle: Classic Ford performance axle known for strength and a removable third member; common in older Mustangs and various performance builds.
- 7.5-inch rear axle: A smaller, older design seen on some lighter-duty cars and early trucks; less common in modern lineups but still present on certain models.
- 6.75-inch rear axle: An older, smaller axle used in some trucks and vans from earlier decades; identification can require careful inspection of stamping or build data.
Knowing which axle type you’re dealing with helps you target the right parts and service procedures. If you identify a code, you can confirm the exact model and gearing through official catalogs or trusted databases.
Decoding the markings and confirming the model
Use the markings you find to determine the axle family and gear ratio. Here’s how to proceed and what to check for if you’re missing a clear tag.
- Record all markings you can see on the tag, cover, or housing. Look for a model identifier, gear ratio, and any date codes.
- Measure or identify key physical clues if codes are unclear: diameter of the differential housing and third member, and the spline count on the shafts can help distinguish between common Ford axles.
- Cross‑reference with official Ford catalogs or reputable axle-code resources. Dealers, service manuals, and established online databases can map codes to specific axle models and ratios.
- Check the VIN or build sheet for original axle configuration. Some vehicles list the axle in the window sticker or build data, which you can use to verify the correct model.
With the markings matched to a model and gear ratio, you’ll have a precise answer for parts shopping, gear‑swap planning, or maintenance planning.
Practical tips and caveats
Not every axle will have a readable tag, and some rebuilt or aftermarket axles may not carry the original markings. If you’re unsure, compare the ring-gear diameter, count visible spline segments, and review the bolt pattern of the differential cover. When in doubt, consult a knowledgeable mechanic or post photos to a Ford‑enthusiast forum for a crowd‑sourced diagnosis.
VIN-based and dealer resources to verify
If you have access to the vehicle’s VIN, several routes can confirm the axle configuration: use Ford’s official parts lookup, a dealership service department, or reputable online VIN decoders that pull build data. This can provide the exact axle type and gearing that rolled off the assembly line.
Summary
To identify your Ford rear axle, locate the axle markings on the housing, cover, or tubes, then cross‑reference the code with Ford’s catalogs or a reliable axle‑code database. If markings are missing, measure key dimensions and compare with known Ford models (8.8", 9", 7.5", 6.75"). Use the vehicle’s VIN/build sheet when available to verify the original axle specification. Accurate identification leads to correct parts, gearing choices, and reliable maintenance.
