tonys,

its this done to make sure that the giff cups do not move when its turning?

cos if uj ,the long end position its fixed, no movement to the long bar, the only piece that its able to move its diff cups,

if use dogbone, the bone its not fixed to any position, its best to use the foam to add tention between the diff cups and the dogbone position, so the dogbone and diff cups will be in a fixed position...and will not moved when its turning....

please correct me if i am wrong.....