* E4OD: A four-speed automatic overdrive transmission. This is likely the original transmission if it's a heavier-duty or higher-trim F-150.
* AOD: A four-speed automatic. Less common with the 351W, but possible, especially in lighter-duty trucks.
* M5OD-R2: A five-speed manual transmission. Also possible, but less common than the automatics.
To know *for sure* which transmission will fit your specific truck, you need to:
1. Check the VIN: The Vehicle Identification Number (VIN) will tell you the original transmission code. You can then use a VIN decoder online to find this information.
2. Look at the transmission itself: If you can access the transmission, the transmission case will have an identification tag. This tag contains the necessary information to identify the transmission.
3. Check your truck's build sheet (if available): If you have access to the original build sheet, that will clearly indicate the transmission used.
Swapping transmissions can be complex and involves more than just finding a transmission that *might* fit. Bolting pattern, bellhousing, output shaft, and even the computer control system all need to be compatible. Using a transmission from a different year or even a similar truck isn't guaranteed to work. Always carefully check for compatibility before attempting a transmission swap.
