E30 LSD Parts

[Jean]

Does anybody have a link to a chart with internal/part numbers?


Something like this but for E30 medium case diff?


http://www.realoem.com/bmw/showparts...33&fg=15&hl=11

[Ian Bowers]

I've been doing the same research as you have (Building a 3-disk diff), and I can not find that exploded view ANYWHERE. However, everything I've found says the diff was made by ZF for Porsche and BMW, so this should apply:

http://www.autoatlanta.com/porsche-parts/9442-89-91/305-05.php

http://e30performance.info/viewtopic.php?f=22&t=939

That thread has some good information in it as well.

[erik325i]

Subscribed for more info. My brother has a 4-disc LSD, and I had a hard time finding any information about it online. Every time I asked a question on bf.c, all I got was "go to diffsonline".

Erik

[erik325i]

Does anybody have a link to a chart with internal/part numbers?


Something like this but for E30 medium case diff?


http://www.realoem.com/bmw/showparts...33&fg=15&hl=11

I don't have an exploded diagram, but you used to be able to buy the clutch discs from Factory 3 Performance. Last year, when they shut their doors, they sent out an email saying you can get the LSD clutch discs from http://www.harrisonmotorsports.com/

Not sure if that helps you or not.

Erik

[Jean]

The clutches I can get, I just need the view to get the other parts as well such as washers etc...

I doubt a local dealer will be able to pull any of this up either.... someone must know.

[Jean]

Ian - those links help! I wonder if they are in fact the same parts or not though..

[Ian Bowers]

Ian - those links help! I wonder if they are in fact the same parts or not though..

People (Yoshi) have put the Porsche dog ear plates in with no issues. I'm ordering up some plates myself. There are a few more links/words that reinforce that they are the same pumpkin. I'm building a 3-disk (Bimmerworld disks) clutch. The LSD I purchased diffs out like crazy.

[Jean]

Why 3 and not 4?? 3 would have un-even load/wear vs 4, no?

Can you post up exactly what you are ordering and from where? :)

[Ian Bowers]

I'm afraid of having too much lock-up with a 4 disk setup(I DD my car), and I didn't want to spend another $75. Metric Mechanic sells a 3-disk diff, so I figured it couldn't be THAT detrimental to the balance/load/wear.

http://www.r3vlimited.com/board/showthread.php?t=156816 -- thread regarding Porsche/E30 similarities.

As far as what I ordered, I ordered the parts shown in this thread. Seals, Bearings, and clutches.

I ordered everything but the clutches from Blunttech, and got them within a day.

edit: Here's Yoshi's video on building a 4 clutch LSD: http://www.youtube.com/watch?v=CM1QE...layer_embedded

[Jean]

Very cool! So, I wonder if ALL e30 medium size stock 25% lock up diffs use 2.0mm size "dog ear" plates?

And I wonder if those smaller washer things (3 on each side) need to be replaced accordingly as well depending on how many clutches you end up using. It seems/looks like they would "center" the clutch-pack or the center section w/in the lsd unit/housing ?

Machining one side down a few mm's to fit another clutch should be pretty straight forward for a shop to do.

Was blunt able to get your the porsche parts?

[Ian Bowers]

Very cool! So, I wonder if ALL e30 medium size stock 25% lock up diffs use 2.0mm size "dog ear" plates?

And I wonder if those smaller washer things (3 on each side) need to be replaced accordingly as well depending on how many clutches you end up using. It seems/looks like they would "center" the clutch-pack or the center section w/in the lsd unit/housing ?

Machining one side down a few mm's to fit another clutch should be pretty straight forward for a shop to do.

Was blunt able to get your the porsche parts?

From what I've read, yeah. All of them used the 2.0mm dog ear plates.

No clue on the washers.

Oh yeah, it's simple simple.

Sadly, no. He tried all of his suppliers with no luck. :(

[Wanganstyle]

Very cool! So, I wonder if ALL e30 medium size stock 25% lock up diffs use 2.0mm size "dog ear" plates?

And I wonder if those smaller washer things (3 on each side) need to be replaced accordingly as well depending on how many clutches you end up using. It seems/looks like they would "center" the clutch-pack or the center section w/in the lsd unit/housing ?

Machining one side down a few mm's to fit another clutch should be pretty straight forward for a shop to do.

Was blunt able to get your the porsche parts?

the machining is actually NOT that easy to do, as its hardened material. Angle grinding set is the most common way to do this and not all machine shops can handle it, Many very good ones actually CANNOT.

grinding has been done in Ghettofabulous fashion by un-named builders, via hand held grinders and you can tell it.

We have sherlock holmes'ed diffs with altered center sections before......My machine shop has been around 50 years........ :)

plates you can use between 1.9-2.1 mm, as other things vary from -.1 to over 1.0 in thickness for different generation of ZF unit ++ wear and you are re-setting everything anyway.

When you dissassemble the unit, measure the exact spec of each item individually and then you can calculate your entire stack height.

[Highway1]

3 discs is easy to do as it requires no machining. there is a spacer that is the thickness of an extra clutch and dogear. just remove that spacer and add.

About it being uneven it doesn't matter if the right side matches the left. The clutches don't link each wheel to the input gear individually. All the clutches do is hold the spider gears from rotating opposite directions.

Adding more discs will prevent overheating(slipping) which is great for drifting. the thicker clutch plates and dog ears give you more lockup. you can change ramp angles but there is no proven right way to to that.

[Jean]

the machining is actually NOT that easy to do, as its hardened material. Angle grinding set is the most common way to do this and not all machine shops can handle it, Many very good ones actually CANNOT.

grinding has been done in Ghettofabulous fashion by un-named builders, via hand held grinders and you can tell it.

We have sherlock holmes'ed diffs with altered center sections before......My machine shop has been around 50 years........ :)

plates you can use between 1.9-2.1 mm, as other things vary from -.1 to over 1.0 in thickness for different generation of ZF unit ++ wear and you are re-setting everything anyway.

When you dissassemble the unit, measure the exact spec of each item individually and then you can calculate your entire stack height.

Ok, I am going to bring my netbook with me tomorrow to a local machine/diff place to show them pictures of the e30 diff and see what they'll say about machine work.

I am leaning towards ordering 4 of the motorsport clutches here

http://store.bimmerworld.com/motorsport-limited-slip-clutches-p584.aspx

Then I need to also contact local Porsche race/repair shop and see if they can source me the washers/dog ear plates.

And hit up blunt for the other needed parts as well.

Fuck, this is a lot of work.

[Wanganstyle]

You need to bring them a center piece, as its hardened material and they should get a scope on it if they are going to be grinding down- tear down a
Dead LSD and bring guts to them or just call and ask if they can handle machining or grinding hardened steel if you don't have a sample to bring them, the zf unit was designed by Dr Porsche a long time ago, some American cars have very similar center sections as well.