Winter Diff refurbish

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paultv
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Tue Dec 17, 2019 10:49 am

Finally finished re building and re furbishing my 3:46 open diff... out with the 3:73 limited slip unit for now.

PSX_20191217_114235.jpg

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
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aimlessrock
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Tue Dec 17, 2019 1:57 pm

that looks factory fresh..
E30 320i Convertible (1989)
190 Mercedes (1988)

"there is nothing more expensive than a cheap E30"
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paultv
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Tue Dec 17, 2019 3:46 pm

I didn't take a shot of it before - it was a massive rusty rancid heap of junk!

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
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flybynite
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Tue Dec 17, 2019 4:08 pm

Did you swap the internals or just the whole unit? Just wondering if you had to do much to the preload and backlash.
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paultv
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Tue Dec 17, 2019 6:40 pm

I took everything out except the pinion gear - re used the same input nut/washer after having marked it's position carefully - as per Bentley - checked the pre-load - it was close to 2Kg - as the bearings have not been replaced I guess some wear would be expected - as far as I know there should be about 2.5 kg for the pre-load for new bearings.

The output bearings also remained unchanged - everything felt and looked very good - so the only thing is to mark which side is which for the bearing holders and the spacers - the gear mesh pattern looks fine both forward and reverse - in other words, on both faces of the drive gear... so although the diff was in terrible condition, all the seals, dust covers were rotted away - the internals looked very clean, quiet and no strange marks anywhere.

This is going to be my winter "autobahn" unit for some of the long drives I do in Europe - should feel a bit less busy at 140 - 160kph - with the 3:73 first is almost unusable, or at best a bit pointless unless I'm pissing around on dry backroads in the summer for fun! and being able to drive fast here, it will be good to get the revs down a bit -

Next few weeks will tell, I've got a noisy rear bearing so the back ends all coming out -


Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
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flybynite
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Tue Dec 17, 2019 8:00 pm

Good work!

Let us know how you find it , I'm having a bit of back and forth over the ratio for one of mine. Only want to do it once ideally
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paultv
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Tue Dec 17, 2019 8:13 pm

I'm a bit mad thinking of having a swap out diff whenever I feel like a change!

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
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Foe
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Tue Dec 17, 2019 10:48 pm

Nice work Paul :thumb:
magpie
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Wed Dec 18, 2019 12:08 am

paultv wrote:
Tue Dec 17, 2019 8:13 pm
I'm a bit mad thinking of having a swap out diff whenever I feel like a change!

Paul :-)
did you buy my 6 speed box set up ?
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m52 b30 stroker 6-speed 318is Galvanizer
m42 touring
+ a yard full of scrap turds :)
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paultv
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Wed Dec 18, 2019 9:11 am

Nope... but what exactly was it??

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
magpie
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Wed Dec 18, 2019 11:45 am

sorry,got you mixed up with someone else
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m52 b30 stroker 6-speed 318is Galvanizer
m42 touring
+ a yard full of scrap turds :)
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