Steyr through the shaft for the bridge on the important transmission parts,transmitted to the role of the rear drive axle.The quality of a direct impact on vehicle quality is normal or not.Input spline original drawing structure for the rectangular spline, processing technology: rolling rectangular spline a – grinding cylindrical c – knurled key d – heat straight after the c – grinding rectangular spline a. In 2007, the company tried to change the str through the shaft spline involute spline, and a small batch of trial processing, processing technology as follows: hot pre-grinding cylindrical b – rolling involute spline a —- Hot pre-grinding cylindrical c – knurled key d – hot straighten c – hot straighten b, spline connection to involute, eliminating the original rectangular spline grinding cracks, but the phenomenon Need to add an external grinding process before the hot c, but also because of the heat after the need to meet at the same time a, c at school straight precision, to the processing of great difficulties, and the production efficiency is affected to some extent.