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Identifying LSD limited slip differential

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cobbler2u
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Identifying LSD limited slip differential

Post by cobbler2u » Tue Dec 18, 2012 11:14 pm

Hi
Can anyone confirm the numbers on an lsd.
Been oferd one with these numbers on
33:1 / 1204 898 / 2.2 2.25.

Cheers

Mod: topic title edited, this one might go into the top tech topics or FAQ section.



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Jeroen
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Re: lsd id

Post by Jeroen » Tue Dec 18, 2012 11:41 pm

That's only the part no for the cover which is the same for all diffs. A LSD should have a white S stamped on the housing (usually that's gone) and a metal tag bolted that says S3,45 for a 3.45 Sperre for example. Most times that tag is gone as well. Even testing it (output flanges should turn in the same direction if you turn the input flange) is said to fail with some versions even though that worked out well all the times I found a LSD. And when you open up the unit the actual unit should say S25 for 25% limited slip... whatever's left of those 25% over time, abuse and incorrect oil of course.

Some examples thanks to Madhatter:

Image

Image

Image

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search engine sperre differentialsperre sperdiff sperdifferentieel sperrdiff sper sperr diff sperklok 25% 40% 75% 3.45 3.64 3.91
Regards/groeten, Jeroen

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Wondermike
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Re: Identifying LSD limited slip differential

Post by Wondermike » Wed Dec 19, 2012 6:31 pm

I did find a tiny S next to the back plate that gave it away.
The rest of the diff was so rusty that i didn't find any other clues on it.

Image
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Lars-Nord
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Re: Identifying LSD limited slip differential

Post by Lars-Nord » Fri May 03, 2013 9:51 pm

Now it has happened thing with my car. I had it jacked up to replace hardy disc. When the exhaust system was in place, it's a little tricky to get in place. Alpina made ​​slightly larger exhaust system and it`s going over the right shaft. It's a bit cramped and I have to spin a little on the mid shaft to check for subs. Then began both wheels to spin the same direction. A little surprised, I put the car in gear and started it. The wheels spun in the same direction. I tried also to hold back one wheel, but it was not possible. So now it looks as if the differential has gone from open to LSD.

Can it be so that LSD has not worked, because the car has been too much still? When I bought the car, then spun the wheels opposite directions???
81 e21 323i polaris
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Wondermike
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Re: Identifying LSD limited slip differential

Post by Wondermike » Fri May 03, 2013 10:11 pm

Open the rest cover and you know for sure.
So many cars, so little time

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Lars-Nord
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Re: Identifying LSD limited slip differential

Post by Lars-Nord » Fri May 03, 2013 10:20 pm

I will try that next week and put on the Alpina cover. ;-) Or not.... Have to make another bracket. Shit.
81 e21 323i polaris
That's a whole lott of engine under the bonnet;-)

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Lars-Nord
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Re: Identifying LSD limited slip differential

Post by Lars-Nord » Tue May 07, 2013 11:09 pm

This is also a way to find out.

Image
81 e21 323i polaris
That's a whole lott of engine under the bonnet;-)

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