bmwe21.net forums

Hi , are the 3.45 diff from a 2002tii and e21 6 cylinder the same? I.e the way it mounts and the same fitting?

I seem to recall 2002tii diffs are 3.64 ratio which is the same as a 320/6 . 2002 short nose diffs have 8mm bolts to the output flanges which early e21,s up to about 1978 also had. later e21 diffs had 10mm bolts which had a slightly different p.c.d and i think the output flanges were slightly narrower on the later diffs . To fit a late e21 diff on a 2002 the output flanges need new holes drilling and tapping and spacers between the flanges and the driveshaft c.v joints .....edd..below is a link to a page that you may find interesting.

http://www.bmw2002faq.com/_/technical-a ... -build-r74

Yh cheers but I was planning the other way round by putting the 2002tii diff in my e21 as it's 4 speed and the 3.45:1 ratio works well with the 4 speed manual box