e30 lsd diff

[JayCee 26]

I have a 4.1 open diff in my 1990 325i

I see on ebay for a lil over $300 nz i can get the insides of a 4.1 lsd shipped.

Is it a straight swap over, the insides of mine with this and hey presto i have a 4.1 lsd or is it a bit more complicated than unbolting diff amd swapping over?

[e30ftw 396]

Yes it is as easy as that.

The LSD center can fit any diff (so long as it's for a small case or medium case you need the right center for each size).

You just pull the diff out, open it up, remove the axles and take the ring gear off the open center, put it onto the LSD center then put it back together.

You can DIY it, alot of people have. I did one in my last, changed my open 3.64 bought an LSD center and swapped it in. Though I bet someone here will chime in get it done properly at a diff shop - Which is probably the smart thing to do if your cautious about things

[JayCee 26]

Yes it is as easy as that.

The LSD center can fit any diff (so long as it's for a small case or medium case you need the right center for each size).

You just pull the diff out, open it up, remove the axles and take the ring gear off the open center, put it onto the LSD center then put it back together.

You can DIY it, alot of people have. I did one in my last, changed my open 3.64 bought an LSD center and swapped it in. Though I bet someone here will chime in get it done properly at a diff shop - Which is probably the smart thing to do if your cautious about things

Oh cheers bro, im keen as to diy it. Im cautious but i will cut corners also haha if i get confused then il ask for help

How longs it take to do?

[e30ftw 396]

Can't remember was so long ago since I took an e30 diff out. I'd say give yourself an entire afternoon to remove the diff, disassemble then reassemble then install back into the car, so a few hours give or take if you have done it before and know how to get it out quickly.

Pulling the diff apart is pretty straight forward, but the hardest part is removing the ring gear from the open center. The bolts are insanely tight.

[Ahmedsinc 414]

Are 188mm diff centers capable of being retrofitted with the necessary clutch discs to rebuild them as LS? Have got a 3.15 medium case (unsure if it's LS but am assuming it's not) coming at some point in the near future and would be stoked if I can set it up as limited slip to make the most of the manual conversion.

There are a few threads floating in the ether saying the 944 (?) Porsche clutch plates are the requisite 2mm (think another model has 2.1mm, which looks to change the slippage %), and going by the prices on Pelican they're a damn sight cheaper than the BMW ones.

Apologies for the noob questions, diffs are a mystery to me at this point in time, though I'm trying to pick up what I can

[JayCee 26]

Im no expert myself mate but i am pretty sure it should be straight swaps. Both are medium case so im sure there isnt a difference i. Size. Had a 3.64 lsd in my last 325i last year shoulda kept the damn thing

[e30ftw 396]

If you mean an open center converted to an LSD then no, You can only make a Limited Slip diff using a LSD housing which is a closed unit (has clutches and stuff inside you can modify to make it tighter). The open center is just a rotating gear housing of cogs really, Can't do anything with it.

LSD:

Open:

Edited April 11, 2013 by e30ftw

[JayCee 26]

If you mean an open center converted to an LSD then no, You can only make a Limited Slip diff using a LSD housing which is a closed unit (has clutches and stuff inside you can modify to make it tighter). The open center is just a rotating gear housing of cogs really, Can't do anything with it.

LSD:

Open:

Oh i see haha didnt understand it properly.

Im replacing the whole centre piece into my diff case though correct?

[Ahmedsinc 414]

Yup, that answers that question then, ta. With the e30 medium case diffs, are there any marks on the casing to identify as LSD? Aside from the S prefixing the ratio on the tag?

[e30ftw 396]

Yep, An LSD center is the entire middle housing. You pull the side flanges out, which have shafts going into each side, then the center falls right out.

Then as you can see on the left side there are a bunch of bolts that are holding that ring gear to the center.

Edited April 11, 2013 by e30ftw

[JayCee 26]

Theres usually a s stamped on the casing itself

[JayCee 26]

Yep, An LSD center is the entire middle housing. You pull the side flanges out, which have shafts going into each side, then the center falls right out.

Then as you can see on the left side there are a bunch of bolts that are holding that ring gear to the center.

Are these the suckers that are tightened hardcore as?

[Ahmedsinc 414]

Final dumb question for the night- where on the housing is this elusive "S"?? Just been for a quick look & all I've found so far has been M & W, plus a bunch of numbers.

Starting to wonder if what I've bought might not be what I thought it was

[JayCee 26]

Final dumb question for the night- where on the housing is this elusive "S"?? Just been for a quick look & all I've found so far has been M & W, plus a bunch of numbers.

Starting to wonder if what I've bought might not be what I thought it was

Pretty sure its stamped / or painted on top of casing. Dont think my 3.64 had it maybe came off after time but was defs a slipper. Cant you test by turning one side whilst holding the other side and they should both spin in same directio..

Something along the lines of that. Dont quote me though

[Ahmedsinc 414]

Tag only has 3.64 stamped onto it, casing is still covered in 30 or so years worth of road grime so no clues there. Screw this, will pull the cover off tomorrow after work. Not gonna be a happy boy if I find an open centre!

Strangely, when you turn either output flange or the input everything turns in the same direction, as i would expect from an lsd, though as soon as resistance is applied you can get it to slip pretty easy. Am thinking the clutches are stuffed.

[e30ftw 396]

Were you told it's an LSD? The tag would normally have the S stamped into it with the ratio.

[thorburn 120]

There is no sure way of telling unless you take the back cover off.

People (scumbags) swap tags. The "S" is printed on some non lsd diffs as well

[Ahmedsinc 414]

Were you told it's an LSD? The tag would normally have the S stamped into it with the ratio.

Wouldn't have bothered buying it if it wasn't.

Pulled the cover off this afternoon to discover.......

Only reason I bought it was for the LS carrier. really disappointed, the seller was a member on here. Will get in touch with him and find out what the story is before I start making any loud noises.

Sucks

Edited April 12, 2013 by Ahmedsinc

[JayCee 26]

Wouldn't have bothered buying it if it wasn't.

Pulled the cover off this afternoon to discover.......

Only reason I bought it was for the LS carrier. really disappointed, the seller was a member on here. Will get in touch with him and find out what the story is before I start making any loud noises.

Sucks

Bro that sucks. If they sold it to you saying it was LS then they should defs refund you.

[Ahmedsinc 414]

Bro that sucks. If they sold it to you saying it was LS then they should defs refund you.

Well, the ball is in his court. Contacted earlier & informed that what I was sold are definitely not the goods described.

Serves me right for thinking I was getting an LSD for $70

F*^%!!!!!!!!!!!

[e30ftw 396]

Ha, Well for that price no way it was going to be an LSD. But still that sucks.

[Ahmedsinc 414]

Lesson learned. Seller not willing to do anything, was "unsure" if it was limited slip or not, although I recall a different tone to the conversation it's my word against his

Lesson #1: NEVER buy parts unless you either know the seller is informed & legit

Lesson #2: If someone offers you an LSD for $70, it's probably not LSD.

Dumb me (sorry for the thread jacking OP)

[JayCee 26]

Lesson learned. Seller not willing to do anything, was "unsure" if it was limited slip or not, although I recall a different tone to the conversation it's my word against his

Lesson #1: NEVER buy parts unless you either know the seller is informed & legit

Lesson #2: If someone offers you an LSD for $70, it's probably not LSD.

Dumb me (sorry for the thread jacking OP)

Been interesting reading this dude. Why dont you buy the LS inners like me and use this casing. Could be a good little project mate

[Ahmedsinc 414]

Been interesting reading this dude. Why dont you buy the LS inners like me and use this casing. Could be a good little project mate

Well at least it gives me options I suppose. Already have an E36 3.73 plus I've got a 3.15 open on its way soonish. Got any links to the ebay seller you used? Ideally I want LSD for the soon to be fitted manual kit for the 325i, still deciding between the .15 & .64 ratios. The E30 medium casing is of no use in the E36 so will definitely become a parts donor at some point.

Back to the drawing board!!

[pldubs 308]

Ill put my hand up and say I sold the 3.64 that didnt turn out to be LSD.

I took it out due to it being noisy ( could have also been the f**ked wheel bearing but took it out anyway )

It always spun 2 wheels and behaved like an LSD so I was convinced, but due to excessive noise I thought it was only worth what I paid for my replacement, $60. I honestly regretted selling it up until tonight when you contacted me because I realised how much e30 LSDs are worth.

Once again sorry bro, but im not going to bother getting you to ship it back to me just so you can regain $20 ( probably less seeing as I hooked you up with shipping ) from an unfortunate circumstance.

EDIT: Shipping would have been $76.48 for a cash sale.

Edited April 12, 2013 by pldubs