So i was under my car today cutting and replacing some rusty exhaust tubing. i was looking at my diff and i noticed yellow numbers in paint, looks just like the junkyard marks on my alternator, so im thinking mabey this is an lsd. i didnt have time to look as it was getting dark and i needed to finish welding. so i took it our for a spin and everytime i did a burn out it left 2 solid black stripes. what do you guys think? Does anyone have a pic of a stock '87 diff? thanks a lot.

 

with the car in neutral and the ebrake off, jack the back of the car up and spin one wheel. see which way the other wheels spins.

 

well i cant right now. but shouldnt the both spin the same way.

 

S4 Limited Slip Diff. Typically LSD's will have a tag on the FILL (upper) plug that says LIMITED SLIP ADDITIVE REQUIRED, or something to that effect.

My S4 Open Diff looks exactly the same.

 

well i left my jack at a friends but i got under the car. it looks ecactly like that but i couldnt move well enough to see what the fill plug said.

 

what model do you have.

And two burn out strips mean you hve a traction problem... it has nothing to do with a LSD

 

i have a base model.

 

well then it didn't come with a LSD. You would need to jack up the rear and, turn one wheel and see if the other moves the same direction or the opposite direction to see if someone swapped in a LSD

And as a note, if you have the base sized wheels and tires, and you couldn't break both tires loose, I would be surprised.

 

You spin one wheel forward and the opposite wheel should turn in reverse.

 

if you have an open diff, yes.

However if you have a working LSD, they both will spin the same direction

 

i knew the base didnt come with an lsd which is why i never looked into it.

well the last burn out i did left about a 15 foot double stripe. i can get the tires to totally break loose. fairly new tires too.

 

To tell what type of diff it is, turn one wheel and watch the other.

Open diff = wheels turn opposite direction (one forward, one back)
Clutch diff = wheels turn same direction (both towards front or back)
Viscous diff = other wheel doesn't turn or takes a sec to move in the same direction.


so viscous diff still go the opposite way if the diff (pumpkin) is out of the car?

 

that the difference between and open diff, clutch diff, and a viscous diff. well the other day i jack my car up and found a tag that says lsd. its a S4 Gxl

 

Yes, a 86-88 GXL should have a factory LSD

 

ok, now im confused. i have an S4 sport. and the sticky FAQ says no sport from 87 had an LSD. but when i jack the car up, one wheel turns, and the other just sits there. if i spin it for a while, then the other one will start to move. and it dosent seem to matter which side its on....so? do i have an LSD?

 

Not from the factory.

And for it to have a viscous diff that someone installed after the fact, then it would take a spin or two and then spin the same direction.

Anytime a wheel spins the opposite direction, it is an open diff

 

put in gear, i did the same thing and was so happy till a friend said "NOPE.....TO BAD"

awwwwww no lsd lol

 

icemark i pm'd you

 

does it matter if its in gear or not?

EDIT

nevermind.

 

i tink so...........

 

ok....so i read that a miata LSD will work in my S4. Does anybody know and i swear i saw it some where here, but does anyone know the link??

 

no, i cant remember where the link is, but if you type "miata LSD" in the search, you will get a bunch of anwsers, and its like the 3rd or 4th one down. its the torsen diff from the 94-97 miata 1.8 liter. and it fits all 2nd gen. NA diff boxes, but something about equal link driveshafts or something...i dont remember...im tired, ive been looking for one also for the last several days. nothing yet, but if you find a source, let me know, the cheapest ive found so far is 750 plus 50 shipping.

 

what the f***! if i spin one rear wheel of my S5 TII the other one doesn't move, even after several revoultions of the first one! what't up with my diff? i think S5 have LSD? what's wrong with mine??

 

your diff might need to be rebuilt. only S5 GTUs(note the "S") and Turbo models have VLSD.

 

so my diff might be worn out?? 'cause i had some serious traction problems at the 1/4-mile this summer! i had one choice: launch like a grandma', everything else was wheels spinnin' like crazy...