Axles, C-Clips and Girdles

Let’s recap what is going on: The starter turns the flywheel; this turns the motor, which turns the transmission, which then spins the driveshaft and turns the differential. The differential now turns the axles and makes the car move. Axles contain splines on the end of the shafts. The more splines there are, the stronger the axle is. Stock axles have 28 splines which do alright for normal driving but with sticky tires, they tend to bend. Standard practice is to upgrade to 31 spline axles. To upgrade the axles, you also need to upgrade the differential since that has a 28 spline formation. By switching to stronger, higher spline axles, it allows you to launch at high RPMs with slicks and not having to worry about snapping an axle. Moser makes the strongest axles, bar none.

C-Clips are the worst items ever to be made for the rear end. If you look at the 1^st picture, you’ll notice some plates that contain 4 holes. Those are what normally house an axle in the axle housing. By bolting the axles in, they will never fly out if something bad were to happen. In the 2^nd picture, however, are c-clips. These items are very well known in the Chevy community and are slightly less known in the Ford community. The 8.8’’ rearend contains c-clips to hold the axles in place instead of plates. If an axle were to break or fail for whatever reason, the axle would fly out of the rearend. C-clips also prevent easy differential changes. The Ford 9’’ rear has a “pumpkin” which can be taken out and given to a person to install gears. With the 8.8’’, the person must have the whole car lifted and work with the rearend that way. This is much more labor intensive and will result in a higher bill to swap out gears. There are c-clip eliminators out there for our rearend but these are known to leak a little oil and are not an option when it comes to a daily driven car in my opinion. There is also another option of having 9’’ rear ends on 8.8’’ axles but that is kind of pricey.

Girdles

http://www.taperformance.com/rear.htm

Girdles help reinforce the rearend a little bit as well as allowing an extra half a quart of oil in the rear. If you are going to switch to a girdle, I recommend getting a stud kit for it instead of using your stock bolts again. After market girdles generally have bolts that help reinforce the differential bearing caps as well as a handy drain plug. If you are going to install a panhard bar, however, be sure to get one that will clear. TA offers one.