How to find out which LSD you have

[Daniel325i]

I have an 89 325i 5 speed, so theoretically i should have a 3.73 LSD (i think, can someone verify). This is what i want, but, about a month ago i got one tire off the ground (completely) and was stuck (well, i just put it in manual and pushed it...), but, i couldnt get out under my own power, so that leads me to believe that the rear end may have been changed OR my LSD is no longer functioning.

I'll be going under my car later this week so i'll look for that nice little branding indicating that i have lsd or not (its an S right?) while im there.

But, it makes me think, if it is an LSD, what can go wrong internally for it to stop working (poor maintainance, lack of oils, etc). Do you think its possible that it might just need to be opened, cleaned up, and thrown back together and work again?

[x628x]

i was told only the 'is' had LSD. and it was an option on the 'i' i think.

[Teaguer]

Yes your car would have come new with a 3.73 rear end but if its only an "i" model then the Limited Slip would have only been an available option .
The "is" cars came standard with an LS diff .

Chances are your car never came with an LS diff .
But if you decide to get under the car and check , don't plan on seeing the big white "S" stamped on the diff case as its only on the top side .
You will be able to read the tag however .
It will be located on a bolt onthe right just below the speedo pick-up .

http://v6toys.com/is/diff02.jpg

This is mine and it reads "S4.10" that means its a LS 4.10 ratio .
The tag is originally pointed up or vertical from that bolt , I just positioned mine differently and made the numbers more readable after installing a finned cover .

Even a LS can become non-functional , it has a pack of clutches that given enough wear and heat can begin to react like an open diff .

Hope this helps .

[TriFlow]

Just do a burnout and see if you leave 2 patches of rubber.. :D

[Daniel325i]

perfect, thank you.

So since the speedo pick up is in the diff, when we change diffs our speedo will keep operating normaly?

I was under the impression they were in the GB, not the diff. thats awesome (imho). I guess that makes my post in the ground control forum, or part of it, stupid... Oh well.

[318driver]

this should be stickied

[Chris]

this should be stickied

:wink:

[Teaguer]

So since the speedo pick up is in the diff, when we change diffs our speedo will keep operating normaly?

I was under the impression they were in the GB, not the diff.

Yeah all is cool with the speedo when we change ratios in our cars .
Some of the lesser European E30's did hava pick-up in the trans though .

[x628x]

Just do a burnout and see if you leave 2 patches of rubber.. :D

i thought that wasnt true... mine leaves two, and im pretty sure i dont have an LSD. i guess ill have to get under there and check to be sure.

[Teaguer]

Open diffs can leave 2 tire marks sometimes just like a LS diff .

http://v6toys.com/bmw/e21_07.jpg

This pic is my old E21 when it had an open diff and alot of the times it left 2 marks going in a straight line .
But the right rear it the driven when in forward gears .

I just dismissed that remark about burning out and checking the marks because Daniel325 already said he had one wheel up and the other wheel would not move the car . That pretty much sais it all .

[x628x]

would one of them be lighter, like it is on the pic with the e21? cuz i dont think mine is when i burnout.

[Teaguer]

Under ideal conditions they would be the same .
But most of the time one line would be fuller or thicker than the other .

Hey you might have a LS .

P.S. : Did you sell those injectors yet ?

[x628x]

ill have to check next time im at home (maybe this weekend)

no theyre still available.

[Teaguer]

What do you mean ?
Don't you have your Bimmer up in Denton ?
Or do you mean get underneath and check ?

About the injectors :
Did some research at work the last couple of days and found out that for the "i" engines you want to go up to 24lb injectors .
The 19lb injectors are really for the "e" cars .
I could not remember from when I looked into this in the past if I wanted the 19's or the 24's . But now I know I want the 24lb injectors .
For those who are wondering the "i" cars came with 15lb injectors .

Sorry man , but I'll have to pass on them for now .

[x628x]

i thought that the davelength guy had 24# injectors at first, but he was running too rich, so he went with 19#.

yeah the bimmer is here in denton, but i cant really get under it to check.

[atmh]

if one wheel is in the air, the car still might not move even with an lsd, I am pretty sure its only 25%, so if there was soemthign else holding the car in place, its not going to go. of course, if you jack up one rear tire and then get in the car and try to drive, and it drives off the jack, then you know you have an lsd, but thats a bad thing to do, other things you can do are jack up the whole back end of the car and leave it in gear and spin one wheel, if its open, it should be really easy to turn, if its lsd it should be harder, but not too hard, especially with the wheel and tire on giving a lot of leverage.

[BS87]

other things you can do are jack up the whole back end of the car and leave it in gear and spin one wheel, if its open, it should be really easy to turn, if its lsd it should be harder, but not too hard, especially with the wheel and tire on giving a lot of leverage.

Or, just pop it in nuetral, and spin the right rear wheel. If the driver's side wheel goes the same way, it's LSD. If it goes the opposite way, it' Open.

[erik325i]

How do you change your diff? What needs to be done to replace it? It's probably pretty simple, just never done it.

[Nick]

Put the car up on jackstands....

Detach the axles w/an allen socket...
Then detach the driveshaft.
Unbolt the differential.

You get good at it, it's about a 1/2 hour job.

[BS87]

Also have something to support the diff with unless you're hans and frans, it weighs a good 60-70 lbs.

[revhard05]

the only cars to come with the a factory lsd are the 325is and m3 .....the 325es and 318is were factory options

[jogfrogjog]

what about the e36 diffs? any info about them?

[325eTurbo]

Just do a burnout and see if you leave 2 patches of rubber.. :D

i thought that wasnt true... mine leaves two, and im pretty sure i dont have an LSD. i guess ill have to get under there and check to be sure.

IF it leaves two homie, either a brake is stuck on one side hahahahaha or you got a LSD

[325eTurbo]

Just do a burnout and see if you leave 2 patches of rubber.. :D

i thought that wasnt true... mine leaves two, and im pretty sure i dont have an LSD. i guess ill have to get under there and check to be sure.

IF it leaves two homie, either a brake is stuck on one side hahahahaha or you got a LSD

[mulishaflesh969]

what does the S mean? and what type of oil should i use to fill it up?

teaguer and x628x you two live close to me.... up for a meet on monday?

[superj]

s means something in german about being a limited slip diff. search for lsd oil, its been on before but i don't remember what everyone said to use

[balibavarian]

LSD FTW

:search3:

[husyrs]

ya iwanna know what LSD do ihave on my eTA

[irija]

Any information on what the 3.25i cabrios came with? Mine is an automatic and would it make it that much hard to drift or try to learn? I know that it won't perform like a manual, but I just don't have the or the money to change out the transmission just yet. I also am not that versed in changing anything that large out. I wish that I was. The rear diff doesn't seem that hard. I'm haven't been able to life my car up, but I will soon.

[balibavarian]

Swappin autobox to manual tranny.. Forget about it dude, it would save you time, money, sweat n tears just to get another e30 with manual tranny..

[320guy]

Swappin autobox to manual tranny.. Forget about it dude, it would save you time, money, sweat n tears just to get another e30 with manual tranny..

The swap isnt acutally that hard.

[balibavarian]

Well you're probably more skilled than me, or have more time... But to me, it just don't cut it.. IMO

[e30kartsport]

Is Ftw!

[320guy]

How many pages did you have to browse back to bump this 3 month old thread?

[balibavarian]

How many pages did you have to browse back to bump this 3 month old thread?
LOL.. Worse i've seen was 2 1/2 years in this very same forum.. This is nothin.

[thatkrisdude]

just ran across this old thread and thought i should add that the ix has a 3.91 lsd

[320guy]

Oh the irony.

[joonsup]

lol

[320guy]

Almost to the day, a year later...

[Bimmerdread]

Almost to the day, a year later...

Two years later!;)

[E30_3I8I]

check ur diff if it has oil in there... my uncle has a 1970 chevelle ss with in posi and when he did a burn out only 1 tire spun... and when he checked his oil.. it was very low.. he filled it up and it worked again...

[AlienBlood]

check ur diff if it has oil in there... my uncle has a 1970 chevelle ss with in posi and when he did a burn out only 1 tire spun... and when he checked his oil.. it was very low.. he filled it up and it worked again...

hmmm do you think that at some point in the last 5 1/2 years, he might have already figured that out? Let this thread die.

[penetrator]

haha .. good info tho

[54bobby]

the only cars to come with the a factory lsd are the 325is and m3 .....the 325es and 318is were factory options
325es was standard, but only a 279 in early mods and 293 on later mods.