bellicose 9 Report post Posted May 19, 2009 Hey all, how do you tell the difference between big, medium and small case diffs? I'm sellin' a 3.91 diff from a '93 525i auto jap import, a guy asked me if it was a medium case and would it fit in a E30. But before i answered him he bid and met reserve. I don't want him to have to buy it if it won't fit. Anyone help? Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted May 19, 2009 (edited) Its highly likely it is medium size (188) (only the big grunters had 210 large case), no it won't fit. E34 diffs attach differently. An E28 diff case is the same, but you have to swap the drive flanges and rear cover from the E30. The crown wheel and pinion from it can probably be swapped into an E30, if properly setup after. Edited May 19, 2009 by CamB Quote Share this post Link to post Share on other sites
