Small to medium case diff upgrade.

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bmw335icoupe
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Post Tue Sep 25, 2012 10:10 pm

Hello All,

Just wandering if it is straight forward to upgrade a diff
from small to medium case.

Many thanks for input.
cheers.
Peter.
bmw9818
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Post Tue Sep 25, 2012 11:28 pm

simple enough but the nuts are going to be hard to get off!

ideal if you have a ramp you can get some leverage on it, but possible one 19mm nut holding the diff, then four on the subframe! need lots of wd40 firstly i thought the nut was a 22 then 20 as it was caked in shit!

the hardest i found are the prop to diff nuts! there on exeptionally tight and need to be careful as to not round them!,

the driveshaft ones are 8mm allen and come out easily enough but time consuming if your doing it with a ratchet
Grrrmachine
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Post Wed Sep 26, 2012 6:32 am

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greg124
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Post Wed Sep 26, 2012 7:30 am

To remove the prop-to-diff nuts I ground about 2mm off the back face of a19mm ring spanner, thus removing the lead-ins, in order to get more contact surface on the nuts.
Schadenfreude - the German's haven't got a word for that.
bmw335icoupe
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Post Wed Sep 26, 2012 11:36 am

Removing the diff itself should not be a problem as the diff has been previously removed. What I'm worried about is if the medium case will fit with no modifications.
Has anyone than that, please?
Cheers
Peter
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Brianmoooore
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Post Wed Sep 26, 2012 11:47 am

Medium case diff. will fit in place of a small case one with no mods.
It can sometimes be difficult to get a replacement diff. fully into place, and it can appear that two of the holes are in the wrong position, but, once fully there, you will find that the holes are correct.
bmw335icoupe
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Post Wed Sep 26, 2012 11:53 am

Much appreciated.
Thank you All for the time.
Peter.