Im looking at an e30 at the moment that has a medium case 4.4 LSD diff mated to an E36 5 Speed. Suffice to say that it would rip through the gears but not have a very good top speed.
For my purposes a 3.64 diff ratio would be better - I have found a non-LSD medium case 3.64 diff, could i just swap over the crown and pinion to effectively make the LSD Diff 3.64 or is there more to it than that ?
Converting E30 LSD 4.4 Diff to 3.64
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Grrrmachine
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Doing diff work is never as simple as "just swap over". You're best off shooting a PM to username "Gareth" on here for info, but by all accounts it involves access to a considerable toolset.
In your particular case, the 4.4 diff (which BMW never made - it's 4.45) will be small case, and the 3.64 will be a large case; these two are incompatible anyway.
In your particular case, the 4.4 diff (which BMW never made - it's 4.45) will be small case, and the 3.64 will be a large case; these two are incompatible anyway.
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HairyScreech
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Easiest way to tell the case size is to look at the back plate drain plugs.
If they are inline then it is a medium case. (188)
If they are staggered (one offset to the right) then its a small case (168)
If they are inline then it is a medium case. (188)
If they are staggered (one offset to the right) then its a small case (168)
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Superleggera
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Theo - car is not in my hands yet but if I do get it, I will let you know.
It is possible to swap the ring an pinion from the same size case to change to ratio. I encountered this problem when I was sent a 3.91 LSD instead of the 3.25 I requested.
I ordered the 3.23 ring and pinion from another medium case diff and had my mechanic swap them in and it works just fine. But what was said above is correct information, the 4.45 and 4.27 diffs were all small case.
I ordered the 3.23 ring and pinion from another medium case diff and had my mechanic swap them in and it works just fine. But what was said above is correct information, the 4.45 and 4.27 diffs were all small case.
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Superleggera
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Ill get some more information on the diff but I am assured it is a 4.45 Medium case LSD - it is currently on a rally car so likely to have been built up that way rather than a standard item.
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martinpallot
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4.45's came in e28's in medium case and are a direct swap into an e30N-Gen wrote:what was said above is correct information, the 4.45 and 4.27 diffs were all small case.
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gareth
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Yep 4.45's are out there. Not standard on E30's but asthmatic 4 pot E28's had them 
These will be swappable but as mentioned above, it's not 'just' a case of changing parts, there's a considerable amount of setting up do do if you want it to last more than 5 minutes
These will be swappable but as mentioned above, it's not 'just' a case of changing parts, there's a considerable amount of setting up do do if you want it to last more than 5 minutes
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