Other options to replace E12 Diff...

Post your E12 technical questions and comments here. Please, no off-topic posts.

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canada karl
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Joined: Tue Jan 06, 2009 3:50 pm

Other options to replace E12 Diff...

Post by canada karl »

Are there any direct bolt on differentials from later series models that will fit the E12 without modification?
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
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Mike W.
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Post by Mike W. »

Cars that used sideloader diffs were E3s, E9s, E12s and E24 thru 82. You can install later diffs only if you change the whole rear subframe to one from an E28, although apparently it is pretty much a bolt up, but you need all of it, trailing arms, shocks, brakes etc.
Mike W.



1980 528i, 3.5 euro, 5 speed conversion
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canada karl
Posts: 815
Joined: Tue Jan 06, 2009 3:50 pm

E9 Diff

Post by canada karl »

I have a lead on an E9(3.0CS coupe) Diff in a Canadian city. Is this diff the same as the E12 one? It seems that the E9's were built up to 1975 so should be close? Where could I look to confirm? Realoem isn't clear on 3.0 CS info!
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
RDAvena
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Joined: Mon Feb 06, 2017 2:13 pm
Location: Falcon, CO

Re: Other options to replace E12 Diff...

Post by RDAvena »

I currently have an idea hat I am trying to prove.

e12 Sideloaders are 188 mm diffs. E models 23-28-30-32-34 used 188 mm limited slip carriers.
Most common LS upgrade is to swap out the open center section for an LS unit.

I have read and seen pics of one instance where an e21 diff had its open center section replaced with an e36 ls unit.

https://www.bimmerforums.com/forum/show ... o-e21-case

This is simplifying it down to one is 188mm and the other 188mm but if the dimensions and ring gear bolt pattern of say an e28 LS center section is similar to that of the open e12 unit it might save the hassle of swapping out an entire rear end.
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dsw99a
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Re: Other options to replace E12 Diff...

Post by dsw99a »

I was following this lead also a while ago. I swear i saw a listing on ebay for something that was switchable in the sideloader diff. It mysteriously disappearead, hence i could never prove the theory. I was also shamed out of the idea from a few friends, but i know i saw a siddeloader lsd that would fit into the existing e12 diff case. Please PM or share if this comes to fruition. thx.
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dsw99a
Posts: 87
Joined: Thu Jul 30, 2015 1:32 am
Location: Hawaii

Re: Other options to replace E12 Diff...

Post by dsw99a »

I was following this lead also a while ago. I swear i saw a listing on ebay for something that was switchable in the sideloader diff. It mysteriously disappearead, hence i could never prove the theory. I was also shamed out of the idea from a few friends, but i know i saw a siddeloader lsd that would fit into the existing e12 diff case. Please PM or share if this comes to fruition. thx.
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