LSD Rebuilding

[lolcantturn]

My 4.10 small case LSD seems like its hitting the end of its life. My poor M42 can't seem to get my new 205's sideways without massive one wheel spinning. I believe I might have blown the LSD feature of my diff!

That being said, I'm looking to bring it back to OEM lock, probably use the Porsche clutches as they're a bit thicker and will give more lock but that's as far as it goes.
The BMW TIS manual is taken off the Internet so I don't have a clue on how to go about it. Is this a job for everyone? Ive done my fair share of motor swaps and what not but this will be my most "technical" DIY. and is there another TIS online or a read up on how to replace the clutches ? Thanks.

[dustyperez]

http://www.bimmerdiffs.com/

he has great tech articles and sells the dog ears and plates. prices seem good too. and actually the rebuild doesnt look too bad imo

[lolcantturn]

http://www.bimmerdiffs.com/

he has great tech articles and sells the dog ears and plates. prices seem good too. and actually the rebuild doesnt look too bad imo

Way cool! Thanks for the link. Pretty comprehensive.

[Jean]

Here you go, and he is a forum member here - you should read his posts, guy knows his stuff.

http://www.r3vlimited.com/board/showthread.php?t=287474

[Wanganstyle]

My 4.10 small case LSD seems like its hitting the end of its life. My poor M42 can't seem to get my new 205's sideways without massive one wheel spinning. I believe I might have blown the LSD feature of my diff!

That being said, I'm looking to bring it back to OEM lock, probably use the Porsche clutches as they're a bit thicker and will give more lock but that's as far as it goes.
The BMW TIS manual is taken off the Internet so I don't have a clue on how to go about it. Is this a job for everyone? Ive done my fair share of motor swaps and what not but this will be my most "technical" DIY. and is there another TIS online or a read up on how to replace the clutches ? Thanks.

Why limit yourself to a 168mm small case when a 188mm just bolts right in?

the 168mm units are not designed modularly like the 188mm setups (that are in e30's). its also TINY and likes to blow up when abused

Install 4,10 or 4,27 or 3,91 or 3,73 in the 188mm standard + LSD of your choice.

build the OEM 188 LSD to however you like before; or install a Torsen/brand new built ZF/Aftermarket LSD if you don't want to open up yourself a larger can of worms than needed.

If sideways is the desire than 168mm is not the ticket.

[lolcantturn]

Why limit yourself to a 168mm small case when a 188mm just bolts right in?

the 168mm units are not designed modularly like the 188mm setups (that are in e30's). its also TINY and likes to blow up when abused

Install 4,10 or 4,27 or 3,91 or 3,73 in the 188mm standard + LSD of your choice.

build the OEM 188 LSD to however you like before; or install a Torsen/brand new built ZF/Aftermarket LSD if you don't want to open up yourself a larger can of worms than needed.

If sideways is the desire than 168mm is not the ticket.

sideways is not the desire, I'm an auto-x guy myself, but I do need something that promotes a little less one wheel spinning.

These 168mm cases are 20lbs lighter than the medium case, I haven't come close to blowing one up with my M42 (120whp and like 33ft/lbs of torque).
Are there truly little options for rebuilding a 168mm case?

[Herr Faust Schinken]

metric mechanic will build you a small case but its not going to be cheap

[Wanganstyle]

metric mechanic will build you a small case but its not going to be cheap

So can I or D.O.l. or Blanton.

Doing up a 168mm to the ultimate requires a true 2002/e21 lsd for the internal spiders

+
E30/36 late model lsd for the stronger housing/cap. Or billet cap.

I happen to also cryogenically treat some 168mm stuff for strength. The 168mm discs I use are proprietary metal compound instead of organic- everyone has their own setup.

Cheap?? Not at all.

Sent from my GT-N7100 using Tapatalk 2

[Holland]

I don't know about a 168, but a 188 is cake for clutch replacement.

It's really, really simple. it seems complicated until you do it, then you realize it's as difficult as changing a water pump.

The only challenge is remembering the order everything goes in.

[Wanganstyle]

I don't know about a 168, but a 188 is cake for clutch replacement.

It's really, really simple. it seems complicated until you do it, then you realize it's as difficult as changing a water pump.

The only challenge is remembering the order everything goes in.

168mm and 188mm and 210mm come apart and reassemble pretty much the same

the 168mm has no factory allotment for more internal clutch discs on the modern 168mm LSD units; the spiders only have teeth wide enough for 1x clutch discs per side.

the Vintage 168mm units have spiders with teeth wide enough to fit 2x clutch discs; some were avail with different internal configurations from the factory.

If building a 168mm for a E30/E36 one would have to franken-hybrid a Modern 168mm and a Vintage 168mm + custom machine the stack limitations and + proprietary thickness discs/steels to make it a 3 or 4 clutch disc unit.

If building a 188mm one can toss the dead spacer and convert the 2x disc 25% lockup unit to a 3 disc 40% lock up unit- many people are claiming this as a "built" aftermarket diff; its kind of but not really; it will hold 500rwhp for a street car but the internal setting is un-even and to do it properly requires custom thickness items and internals to spread the stress correctly.

210mm units require machining to fit more than standard 2 discs and custom internal stack thicknesses; additional oil paths will also need to be created as machining will remove the oiling passageways of the capsule.


4 disc is the BMW motorsports factory setup style; Deleting the springs is often done by ZF in Ferrari and Alfa Romeo applications; Springs and Preload is for simple very basic setups; for racing use and Auto-X Competition DECREASING preload ideal; One can see the championship lap times put down by OS Giken LSD units and tell that the patented ANTI-lockup function of the OSG is the benefit.