Open diff and LSD cwp interchangeable?

Post Thu Dec 06, 2012 11:14 am

Are the crown wheel and pinions on open diffs interchangeable with LSD units?

Post Thu Dec 06, 2012 12:49 pm

Depends on the ratios, too big a jump and the flange that the CW bolts too will shift over in the case to allow for the size difference

Post Sat Dec 08, 2012 11:23 am

I never knew that, ZF only has one part for the LSD case which implies it accepts all ratios.

I have done a few swaps now, never had a scenario where the offset of the CW was different between the ratios.

However I have only gone from 3.15 all the way through to 3.91.

Andrew

Post Sat Dec 08, 2012 2:31 pm

I was thinking of going to 4.25. So if I got a 4.25 open diff, the crown wheel could be fitted to my LSD unit?

Post Sun Dec 09, 2012 10:32 am

Are you guys sure you are not confusing two LSD units because of Small case and Medium Case LSD's for the E30?

I just had a look and BMW seem to have a different part number for an E36 328i Auto and Manual, the Auto is 3.07 and the Manual is 2.93.

One could conclude the LSD case CW offset 'could' be different, but it could also simply contain different ramps (like I recently found out).

Or

We could conclude that the crown wheel on the 2.93 needs more of an off set than the > 3.XX ratios.

Will try and find some photos online of a BMW 2.93 CW and Pinion.

Post Sun Dec 09, 2012 2:45 pm

Demlotcrew wrote: We could conclude that the crown wheel on the 2.93 needs more of an off set than the > 3.XX ratios.

Pretty much this, I found it when trying to swap from 3.15 to 2.93, you can make a spacer when going the other way. Bigger teeth= bigger CW/Pinion