Differential Rebuild


Is it possible to take an open 3.73 dif and convert it to a LSD? And if so, what parts do you need and where can you get them.


To be legal in this series you would need a BMW diff with an LSD with a ratio that you don’t need.

Easier to find a 3.73 with the diff.


The open diff is a 3.73 from a 89 BMW 325i. Just curious if it’s possible to convert that dif to a factory spec LSD. Is it only a matter of getting the LSD clutches, shims, etc or not even possible.

I get it wouldn’t be easier just to find a 3.73 LSD but is it cheaper. I have an extra 3.73 open diff. Is another option to find a broken lsd (maybe with a bad housing) and swap the inards?


It’s not that easy. You basically need to do the same as this.

This is for a 240sx. I converted my open-> right to a torsion on the left. You still need the diff to convert it; see the big casing.

Note that the torsion is around 500$ for that model.
E30’s you can get a healthy diff for around 350.

Found this while doing so BMW research.: Differential LSD swap
Hope this helps.