E36 diff ratio in E30 casing?

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TomCresswell
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Sun Mar 15, 2015 6:26 pm

Hi, will an E36 crownwheel and pinion fit my E30 casing? I've got a medium case LSD 3.91 and I want to put a longer ratio in it. Like a 2.93 or 3.15 and have seen a few E36 diffs on ebay.

Thanks

Tom
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Sun Mar 15, 2015 7:22 pm

yes it will.
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heathy325
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Sun Mar 15, 2015 7:51 pm

Yes it will I've just done this myself
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TomCresswell
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Sun Mar 15, 2015 8:01 pm

Grand. Thank you.
craigieeb
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Sun Mar 15, 2015 9:28 pm

Is it an easy process?
I thought you needed to space them correctly etc
whats actually involved..?
is it just as simple as taking out/off the old and torquing up the new ratio?
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DanThe
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Sun Mar 15, 2015 9:50 pm

Its not just nuts and bolts as you have to ensure the mesh and preload are correct.

Not all 188 CW/P are compatible with all 188 diff spools, as I explained to you on the phone the other day Tom and im 99% certain you will not be able to fit that 2.93 CW/P to your 3.91 LSD unit
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TomCresswell
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Mon Mar 16, 2015 12:04 am

Aha, forgot about that. Cheers.

If all is well at work tomorrow I'll see you tomorrow late morning Dan.
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TomCresswell
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Mon Mar 16, 2015 6:19 am

craigieeb wrote:Is it an easy process?
I thought you needed to space them correctly etc
whats actually involved..?
is it just as simple as taking out/off the old and torquing up the new ratio?
You want about 6-8 thou backlash (rotational rattle) on the pinion gear when the things torqued up.
HairyScreech
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Mon Mar 16, 2015 5:08 pm

Your far better off with a Z3 6 cylinder diff and just fitting the LSD unit.

It will already come in the correct housing.
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gareth
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Mon Mar 16, 2015 9:58 pm

DanThe wrote:Its not just nuts and bolts as you have to ensure the mesh and preload are correct.

Not all 188 CW/P are compatible with all 188 diff spools, as I explained to you on the phone the other day Tom and im 99% certain you will not be able to fit that 2.93 CW/P to your 3.91 LSD unit
Correct :) 3.15 is the tallest ratio you can fit the E30 spool. You can however move the whole spool (LSD + CW&P) from say a 2.93 E36 LSD into a E30 casing.

They do need to be set up properly though, i reckon 1/3 of the rebuilds that find their way to me are entirely due to someone "having a go at it" :D The shim sets needed to do the job are stooopid money!
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TomCresswell
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Mon Mar 16, 2015 10:14 pm


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