Universal bearing pre-load tool and method for using thereof

1. Field of the Invention A universal differential bearing preload tool includes a pair of opposite cylindrical discs simulating differential bearing cups, a disc spreading device for adjusting a distance between the discs, and a force measuring device associated with the disc spreading device. The opposite cylindrical discs are removably fastened to the preload tool and selected from a plurality of discs having assorted external diameters simulating differential bearing cups of different sizes and manufactures. The bearing preload tool is used for mounting a differential case in a differential housing with a predetermined bearing preload.