HELP! what diff is this? LSD? open? 411:1

[E30killer13]

Hey guys, just picked up a diff and had new seals put in it, by the looks of it it looks like an LSD, but the casting numbers on the side may tell different, trying to fit this into my 325i E30 1990.

what kinda diff is this and will it work? and is it LSD?

image2.jpgimage3.jpgimage1 (4).jpg

[euro2fast4u]

what does the tag say?

[E30killer13]

There isn't one

- - - Updated - - -

I have a feeling its a LSD from a auto 325i....

[euro2fast4u]

Confirm its an lsd:

Hold input shaft still and rotate one out shaft. If second output rotates in same direction = lsd if not its open.

Gear ratio:
paint marker a line on the input and one output.

Next turn the input 10 times and count how many times the output shaft rotates. Divide that number by 10. thats your gear ratio.

[ELVA164]

I'm sure this was just a typo, but it would be 4.11:1, not 411:1. Also, since you have the rear case off you can just count the teeth on the pinion, count the teeth on the ring gear, and divide the two to get the final drive ratio.

[82eye]

the carrier shows it is a limited slip. looks like the thinner crown gear which would be a 3.73 tho impossible to tell. confirm ratio as described above.


edit: btw the contact pattern looks great. think about cleaning it up and installing some new clutches while it is out, there will never be a better time and it is easier than most assume. you get essentially a new lsd for small investment.

with the original diff you can even do a gear change. 4.10 is a bit short for an m20. if i can do it so can you.
this is not a tutorial but hopefully inspires, https://www.bimmerforums.com/forum/s...&highlight=lsd

[E30killer13]

Yeah i can confrim it's for sure a LSD, funny story, my father was given it by one of his buddy's for free having no clue what it was, little did we know it was a perfectly good LSD off a E30 BMW that is now going in ours

how much are these brand new?

and we'd like to rebuild the clutches...don't know how to tho.

- - - Updated - - -

i think it's a 3.73, our OEM was a 4.10 and first gear was short as hell, not to mention my speedo was out by 10km/h