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diff hybrid?

Posted: Mon Jan 19, 2015 7:07 pm
by bosers
Hi, does anyone know if the internals of a med case e39 diff are interchangeable with a med case e30 diff? I'm wondering if I could change the ratio of my 3.91 lsd using taller gears from an e39? Thanks.

Re: diff hybrid?

Posted: Mon Jan 19, 2015 7:21 pm
by age
no e39 cant be used, however you can use, e36, e34, e28 and z3 diffs to make a usable diff

Re: diff hybrid?

Posted: Mon Jan 19, 2015 8:26 pm
by heathy325
I'm currently using a e34 3:23 internals

Re: diff hybrid?

Posted: Mon Jan 19, 2015 8:35 pm
by bosers
Thanks guys. So if I can find a crownwheel and pinion of the right ratio from one of the above then I should be able to swap them into my 3.91 lsd, is that right?

Re: diff hybrid?

Posted: Mon Jan 19, 2015 11:27 pm
by Brianmoooore
bosers wrote:Thanks guys. So if I can find a crownwheel and pinion of the right ratio from one of the above then I should be able to swap them into my 3.91 lsd, is that right?
Yes, but setting the correct mesh for the gears is a bit of a specialist job.

Re: diff hybrid?

Posted: Tue Jan 20, 2015 10:49 am
by HairyScreech
age wrote:no e39 cant be used, however you can use, e36, e34, e28 and z3 diffs to make a usable diff
How come E39 can't be used? I thought all 188 case internal were interchangeable?

As in the case outer changes but the inner parts are nearly standard.

Re: diff hybrid?

Posted: Tue Jan 20, 2015 12:41 pm
by heathy325
Diff mesh can be done at home as I've done it before all you need is engineers ink and patience!!

Re: diff hybrid?

Posted: Tue Jan 20, 2015 1:43 pm
by DanThe
HairyScreech wrote:
age wrote:no e39 cant be used, however you can use, e36, e34, e28 and z3 diffs to make a usable diff
How come E39 can't be used? I thought all 188 case internal were interchangeable?

As in the case outer changes but the inner parts are nearly standard.
The front end of the pinion is different

Re: diff hybrid?

Posted: Tue Jan 20, 2015 5:55 pm
by gareth
heathy325 wrote:Diff mesh can be done at home as I've done it before all you need is engineers ink and patience!!
And a stock of shims - BMW only and extortionate! Not their most helpful bit of design...