Every time you hit the accelerator or brake to increase or decrease speed, your transmission is hard at work, shifting gears and regulating torque. Most vehicle transmissions have an ID code tag that indicates the transmission model, as well as revealing other information about your vehicle. If you own a Ford, the order of the various codes on your transmission tag depends on your vehicle's model.
Park your car and prop the bonnet open. Disconnect the negative battery terminal before you start.
Look for the front rail of the trans case where you should find the VIN. It could also be along the front rail. Find the transmission ID tag on the top surface of the transmission or under a servo bolts on the transmission. An "R" on the servo cover of a C6 transmission indicates that you have an "R" Servo, which only comes on CJ/SCJ transmissions.
Examine the tag, focusing on the set of numbers and letters that are separated by a hyphen. This the ID code, identifying your transmission model. Cross reference the ID code with an online transmission identification database (see Resources). For example, the ID code for a 429 Mustang/Cougar is "PJC-G." The bottom row of numbers is transmission serial number.