* E4OD: A four-speed automatic overdrive transmission. This was very common in this year and model.
* ZF-5: A five-speed manual transmission. Less common than the E4OD.
To know for sure which transmission is in a *specific* 1996 F-250 4x4, you need to check:
* The owner's manual: This will state the transmission type.
* The vehicle's identification number (VIN): A dealer or online VIN decoder can provide detailed specifications.
* The transmission itself: Look for markings on the transmission case.
Without more information about the specific truck, it's impossible to say definitively.