how does an LSD work??

[cschollum]

i have an E34 with im guessing no Limited slip diff, heres the situation, cars on rough ground, one wheel just touching the floor, the other firmly planted on it, i accelerate and the one wheel thats just touching slips and all power goes to that wheel, result - i go nowhere

does this mean i do or dont have a slip diff, and how can i get power to both wheels if one should loose traction?
chris

[Jay 535i]

does this mean i do or dont have a slip diff, and how can i get power to both wheels if one should loose traction?

You don't, and you can't.

That's why an LSD is preferred. It limits how much torque one wheel can waste. Once that spinning wheel reaches a certain speed, the LSD forces some of the torque to the other wheel, getting you unstuck.

[Jay 535i]

presumably i could fit an lsd? its to go on a 525 m20 how many types are there, is there a prefered version?

cheers
chris

Sure you could. As for details, someone else around here will know better than I :)

[632 Regal]

preferred would be a unit that has the same gear ratio as your current unit. as for different styles I dont think you have to worry much with a 1.8 litre engine.

[dacoyote]

http://auto.howstuffworks.com/differential8.htm

[rob101]

are the BMW lsd's the salisbury (clutch) type or are they a torsen/quaife type

[Jay 535i]

are the BMW lsd's the salisbury (clutch) type or are they a torsen/quaife type

The former, I believe. Don't quote me.

[Zeuk in Oz]

LOL : I read this thread heading quickly and thought it said "how does LSD work" : after yesterday's great debate I thought - not again ! :D

Is your car manual or auto, by the way ?

[Zeuk in Oz]

manual 525 m20
I was under the impression that all 5 speed M20 525i cars had an LSD. Is there anay way to check by serial no etc ?

[Jon K]

they work with a little bit of elbow grease provided by two baby rabbits and a gerbil working in unison.

[rob101]

The former, I believe. Don't quote me.

yes thats what i suspected. hehe sorry to "quote" you

[632 Regal]

dont forget the snowballs...
they work with a little bit of elbow grease provided by two baby rabbits and a gerbil working in unison.

[dacoyote]

dont forget the snowballs...

Isn't that what your snowman has... balls of snow?

[dacoyote]

maybe is has, but from what i described, others said i didnt have one??? perhaps i do i cant tell from looking at it

Don't quote me... but I sure think that the LSD was part of the cold weather pakage... (Noted by having heated seats)

Otherwise it's a open... (not the same thing)

[zygoteer]

just as an aside to LSD's ... some people here may be interested in some basic reading about diffs here :
http://auto.howstuffworks.com/differential.htm
and about LSD's in particular here :
http://auto.howstuffworks.com/differential8.htm

[632 Regal]

BIG balls of snow!

[dacoyote]

just as an aside to LSD's ... some people here may be interested in some basic reading about diffs here :
http://auto.howstuffworks.com/differential.htm
and about LSD's in particular here :
http://auto.howstuffworks.com/differential8.htm


This post has some intresting links about LSD's :-)

http://www.bimmer.info/forum/showthread.php?p=124315#poststop

[dacoyote]

BIG balls of snow!

Are they hairy?

[rob101]

hmm this reminds me about a conversation i had with a guy that ran one of the racetracks around here (queensland raceway), he said he had an M3 GTR with a Cam and Pawl LSD, which are seriously old school but i think there are newer similar LSDs coming out with more wear resistant parts (which is the weakness in the design of the Cam and Pawl diff they wear out to quickly) he said it was quite violent when it locked up, you could hear a bang when it locked up. could have been a locker i guess, but i assumed this guy knew what he was talking about (professional rally driver back in the days (70s)).

[632 Regal]

LSD description (http://www.nida.nih.gov/Infofax/lsd.html)

[Jay 535i]

Don't quote me... but I sure think that the LSD was part of the cold weather pakage... (Noted by having heated seats)

Otherwise it's a open... (not the same thing)

I have the cold weather package and no LSD :(

[dacoyote]

I have the cold weather package and no LSD :(

I should have said that better...

LSD was a feature on Manual cars with the Cold Weather Package...

Those of us that have auto's all got a open.... (once again, don't quote me... someone should lay some smack down if I am wrong)

[Kalevera]

All have frictions (which wear out, obviously). The quaife is a $3000 upgrade.

The fun thing to note about BMW diffs is that *no* car that came with ASC/DSC could be optioned with an LSD, with the exception of M cars. These days, you can't buy anything with a limited slip from the factory, and all of the new differentials are shoddily built, designed to last the length of the warranty.

So, if you own an LSD, hold on to it -- it'll be very valuable in a few years.

best, whit

[Torque]

I should have said that better...

LSD was a feature on Manual cars with the Cold Weather Package...

Those of us that have auto's all got a open.... (once again, don't quote me... someone should lay some smack down if I am wrong)Dad's auto m50 525i has a LSD. It also has the Cold Weather Package ... maybe just a coincidence? Who knows

[dacoyote]

Dad's auto m50 525i has a LSD. It also has the Cold Weather Package ... maybe just a coincidence? Who knows

Werid... does he have ASC?

[Torque]

Werid... does he have ASC?No. Car is a 09/90 aka 91

[dacoyote]

No. Car is a 09/90 aka 91

Ahhh werid... I know for sure the ASC used a open from the factory.. maybe thats where the line is.....

[632 Regal]

snow isnt hairy...what you smoking?
Are they hairy?

[dacoyote]

snow isnt hairy...what you smoking?

Grass.....

as in some of the times you can pick up grass is there isn't enough snow.. thus making it hairy