The S spline is a conventional spline stub that will yield a safe, effective and usable stroke of 3. The X spline is longer than the S spline. The X spline is cut for the full length of the spline stub. This gives a bit more than twice the contact area between the slip yoke and spline stub and a stroke of 4-1/2". This in and of itself will net more than twice the life on these two components.

With the XB configuration, we will use a heavy rubber boot which is banded down with stainless steel banding to seal all of the contaminates out and keep the grease in. The XC configuration uses the same slip yoke & spline stub but instead of using the rubber boot, we drill and tap the slip yoke for a grease fitting and use a dust cap which has convolutions that follow the spline stub for sealing. We consider the XB configuration to be the longest lasting and best value.