How to tell if you have an LSD?

[g323]

My 323i has the whole sports setup, even the dogleg gearbox-now, I should have an LSD, but Ive always thought that I didnt but now I dont rememeber why I thought that.

How is the procedure to check? And where on the Differential does it have the numbers? do I have to be completely under the car?

[pthm]

easy way that was explained to me was to pull over to the side of the road wth 1 drive tire in the dirt and one on the pavement, then peel out.

if only the tire in the dirt spun you dont have a lsd, or the lsd is worn out

[Quailane]

Put both tires off the ground and spin one. If the other moves in the same direction it is an LSD. If it rotates the opposite way, it is an open differential.

[pthm]

quailane it wont spin the other one in the opposite dirrection, lol only one of them will spin

[320iCar]

quailane is correct, if its an open diff they will spin different directions. pthm, try it out one time.

easiest way to check is drop the clutch at 3000 and see if you leave 11's haha

[g323]

11s?

[DrewDude320i]

the easiest procedure is to use the search function.

After that, lift up the back end, and spin one wheel. If the other spins the same way, you have a LSD. If it spins the other way, you have an open diff or a broken lsd.

[wayfast]

11s?

you know, the marks left on the ground would look like l l <-- two tire marks

[pthm]

oh woops I misread qualines post lol, sorry. I thought he ment put the both off the road, and into the dirt sorry.

yea if you lift both tires off of the ground, and spin one, if both spin the same way its an LSD,(or possibly possy for that matter), if the other spins the opposite way of the one your spinning

[JusLearning]

Was the LSD optional on a 320i? Or did it only come on the 320is and 323i? Only asking because, I've lifted my car to check before and they turned the same way, and another time they didn't, and the last time they did. I also tried looking for the (S)tamp but I couldn't find it. The cars away for the winter sorry I can't try dropping the clutch, any thoughts?

[sonomaGTLN2]

This is getting almost as absurd as people asking about why their heated mirrors don't work on their 2007 3-series.

[pthm]

just learning- the 320Is technically never existed. the 320is was a name given by enthusiasts for the 320i with the sport package

[g323]

Update, so merry christmas all!,

I just had a moment to jack up both sides of the car. What I found was this:

First try, both wheels spun the same direction for a moment.

Then, I went back and forth spinning both sides, after doing this a couple of times, I now spin one, and the other spins in the other dirrection! what gives!

The numbers I got off of the bottom of the Diff are:

11 1207 219.0 GTS-G40 11'H

24 6 80

From the back of the diff:

Middle
1.3 225

Top
33.11-1 204 898

This provide any clues for anyone?

Thanks!

[mrbobian]

Well if that happened you obviously have an open diff or a worn out limited slip. The first time you turned the wheels it probably didn't "open up" or however a diff works. Much like when you burn the tires on pavement that is really level and equally sticky for both tires, you may leave two marks. The best test is to really burn em' good with one wheel in the dirt I think...

[pthm]

from what I have heard there is a S on the diff to signify a LSD

[320iCar]

yes unless you swap the internal gears from an lsd into a normal diff case. which may happen if you crack your diff housing (however someone would manage doing that)

[ianpringle]

Page 100 of Mike Macartney's "'02 Restoration Guide" has a brief blurb re: how to tell if your car has a limited slip. For some reason (?), I still can't post on this site, but if anyone would like a copy of the article, shoot me an email - Ian Pringle: pringle_5@sympatico.ca

[DrewDude320i]

This is getting almost as absurd as people asking about why their heated mirrors don't work on their 2007 3-series.

no joke. this is ridiculous.

[g323]

Almost a frequently asked question then is it? AKA FAQ? as they say

[DrewDude320i]

no, this doesn't deserve it's own thread in the FAQ. I thought it was common knowledge in the car world, but at a minimum it's all over the internet. google could have given you 220,000 answers in 0.14 seconds.

[HenryHide1886]

if the gear oil is thick then it can cause an open diff. to act like a LSD in the test. g323, check your diff. case for a "S" marking on it. You might want to drive the car around a bit before doing the wheel spin test. But I think that you do not have one.

[m20powered]

Both wheels can spin the same direction during this kind of test on an open diff if the tranny is in neutral (because then the driveshaft can spin, just like when you're driving).

http://en.wikipedia.org/wiki/Differe...anical_device)

[Thecatmilton]

I think my silver car may have a LSD. I did a burnout and I left two marks. My henna red car doesn't do that. However when I jack it up and spin a wheel they go opposite directions which confuses me. Can a really worn out LSD do that? I think I may remove the back cover and check things out inside.

[epmedia]

I think my silver car may have a LSD. I did a burnout and I left two marks. My henna red car doesn't do that. However when I jack it up and spin a wheel they go opposite directions which confuses me. Can a really worn out LSD do that? I think I may remove the back cover and check things out inside.

This is how I check for LSD:
Chock two wheels, front and back. Jack only one rear wheel off the ground. Release hand brake and put trans in neutral .

Put your lug wrench on a lug and turn the wheel. If LSD, the wheel will not turn easily (unless the lsd is worn out). There is a torque spec (how much torque it takes to turn the wheel hub). For a good LSD the torque required to turn the wheel hub is - I forget! (?? somewheres around 30-40 lbs/ft ??). If it's an open diff, the wheel will turn with very little resistance.

Edit:
I edited this, because I totally brain farted on the 'open diff' explanation

[pommeree]

Put your lug wrench on a lug and try to turn the wheel. If LSD, the wheel will spin with some resistance. If the wheel does not turn, don't break the lug trying to turn it, it's an open ...

That's the opposite. An LSD is designed to resist the rear wheels moving independently. An open will let the wheel spin in the above test with only the resistance of having to move the diff & driveshaft.