* Short shaft: Used in vehicles with a shorter distance between the transmission and the differential. Generally found in cars and smaller trucks.
* Long shaft: Used in vehicles with a longer distance between the transmission and the differential. Common in larger trucks and some SUVs.
The internal workings of the transmission itself are identical; only the output shaft length differs. If you try to install the wrong length shaft, the transmission won't physically connect to the driveshaft. You'll need the correct length to ensure proper installation and function.