Rear end Question

[big gear head]

I'm assuming that you mean semi-floating axles and full floating axles. The semi-floating axles bear the weight of the car on the axle shaft itself, where the full floating axles only use the axle shaft to turn the tires. Full floating axles have 2 tapered bearings inside a hub on each end of the housing that bear the weight of the car and the cornering loads. This is what is used in NASCAR and other forms of racing where high corner loads occur. It is also used in the top alcohol and top fuel classes of drag racing.