first off, im going to be getting a daily driver FC to compliment my Project FC, i was thinking of something not turbo, and that has a LSD, that would be a GXL right?

ok my second question is how would i go about telling if its shot, im not too familiar with LSDs and how durable are they on the S4's ?

 

Unless you get it low mileage, don't hope for a fully functioning LSD. It's a clutch type, the friction surfaces will wear. S4's are rare to find, even more at low mileage.

FAQ has all the information on which models had and didn't LSD.

 

You can always have it rebuilt if you're worried.

 

do a burn out...look at pavement.
2 lines of rubber equals one workin LSD.

 

A lot of these S4 clutch type LSDs are in pretty bad condition when you find them used or at the junkyard etc... Your best bet is to do a fluid change without any LSD additive and see if it chatters on you. If so add a little bit of LSD additive at a time until the chattering goes away. Most of the LSDs out there are so worn out you don't need any LSD additive... Less additive means more lockup.

 

I got mine with unknown milage. When I spec'd all the plates, they were each in the high range of thickness spec. The thrust washers, however, were corroded and worn. I replaced them with the thicker Mazda Motorsports part, which would make lockup happen a bit faster.

Preload on these diffs was very low, like 30-40ft-lbs. I think that's why people think they are "worn out."

 

how much would it be to rebuild it ?

 

You can jack up the car in the rear end. Either side works. And try to spin the wheel thats in the air. If it moves easily then its worn pretty bad. If it hard and it trys to turn the engine, then it might be in decent shape.

 

Not always true.

I did a burn out in a beat up old '86 SE. It had a stock open diff with around 230,000 miles on it. It left two solid black stripes in first and then a blank spot between frist and second, then two more black stripes. Once again, a fully open diff can make two black stripes.

My GXL on the other hand, (which has an LSD with 178,xxx miles on it) will diff out and spin the right tire when ever it feels like it except when turning left. It will light 'em both up and do a wicked burn out/slide when I turn left. I think it all has to do with the way the clutch discs wear on the older LSD's.

 

You wont know until you take it apart and measure everything. Don't listen to anyone who says "it WILL be $400,569,395 to rebuild it;" you only have to replace whats worn. In my case it was just the thrust washers. You can look up the part prices on Mazdatrix.

 

I'll sell you a s4 n/a lsd. Recently rebuilt.

 

I too have left 2 burn out marks with an open diff..... However I have left darker and far longer burn out marks with an lsd.

 

So I'd like to revive this one up for a question. In the FAQ it only gives diff. information on US models and still doesn't have non-US information there.
My friend has an 1988 NA FC that he's going to be parting out, I just want to know if his particular model has the clutch-type LSD or an open diff. In Canada, is the GXL the only Nonturbo model that had an LSD?

 

jack the rear up and turn the tire, if they both turn the same way, it has lsd.

 

Not if it's worn out though from what I understand... and the car has over 200,000km on it.

 

There will be a Tag on the drain plug of the diff and ya it will be an LSD if its an S4 GXL

 

Even if it is REALLY worn out at first both tires will spin the same direction... even if for half a second lol. If it was open it will be immediate one tire spinning opposite then the other.