diff hybrid?

Mon Jan 19, 2015 7:07 pm

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.

Mon Jan 19, 2015 7:21 pm

no e39 cant be used, however you can use, e36, e34, e28 and z3 diffs to make a usable diff

Mon Jan 19, 2015 8:26 pm

I'm currently using a e34 3:23 internals

Mon Jan 19, 2015 8:35 pm

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?

Mon Jan 19, 2015 11:27 pm

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.

Tue Jan 20, 2015 10:49 am

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.

Tue Jan 20, 2015 12:41 pm

Diff mesh can be done at home as I've done it before all you need is engineers ink and patience!!

Tue Jan 20, 2015 1:43 pm

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

Tue Jan 20, 2015 5:55 pm

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...