* Vehicle Identification Number (VIN) Decoder: This is the most reliable method. Use the VIN (located on the driver's side dashboard, usually visible through the windshield) and input it into a Ford VIN decoder. Many online services (some free, some paid) provide this functionality. The decoder will reveal the axle ratio and potentially other axle-related information. This will give you the code indirectly, as the axle ratio is what defines the axle type.
* Sticker on the Driver's Side Doorjamb: Check the sticker on the driver's side doorjamb. This sticker contains information about the vehicle's specifications, including potentially the axle ratio. Again, this gives you the code indirectly.
* Build Sheet (if available): If you have the original build sheet from when the vehicle was new, this will have precise details, including the axle code.
* Differential Tag: There might be a tag on the differential housing itself containing information, but it is less likely to have the "axle code" in the format you might expect. It may have the ratio.
Why you won't find a simple "axle code": Ford doesn't typically use a single, easily identifiable "axle code" stamped on the component. The information is distributed across various sources, as outlined above, with the axle ratio being the key identifier of the axle type. Once you know the axle ratio (e.g., 3.73, 4.10), you can then cross-reference it with Ford parts diagrams or manuals to determine the specific axle assembly used.
