tranny diagnosing question...LSD or not
 

I recently purchased an SC to use as a daily driver and apparently it was ordered with a Limited slip diff. I have one in my other car and I know the wheels are supposed to spin the same direction with the LSD and the opposite direction with an open diff.

Well on this SC, if you spin one tire manually, the other one does not move at all. Both can be moved independantly but it does not affect the other side.

What tranny do I have or is there a problem with the internals of the tranny...everything seems to drive fine though

Any help would be much appreciated.

Chris

Either a malfunctioning limited slip or no limited slip...

Chris:
My LSD works as described: Turn one wheel and the other one turns in the same direction.
Hope someone knows the answer to your riddle.

Is the car in gear or neutral?

the disks do wear, causing the break away force to asymptotically approach zero

the dynamic breakaway force will always be greater as the applied torque increases

so could it be worn discs? Is this part of a general rebuild or does it involve replacement of the LSD? What is the damage on something like that?

Yes, the car was in nuetral.

Yes, they lsd did can be rebuilt w/ new friction discs, IIRC ~$700

Even worn discs will turn other tire in same direction if both are off the ground and brake ain't binding.

If other tire doesn't move at all, you have plain vanilla open diff.

Look at the bottom series of numbers on the transaxle casing... look for the "-12" between the type# and serial#. If it's there, it should have LSD.

- Wil

That most certainly is not true. I have a lsd equipped G50 in my gararge right now. Worn discs and no rotation of the opposite wheel.

Discussions w/ several well respected transmission/diff guys confirm it.

OK, so I looked at the original bill of sale from the factory and the car was supposedly delivered with a LSD tranny. If I have a worn disc, is there any problem with driving it as is? The rest of the tranny works well...little hesitation in some gears and careful downshifts. I guess the question is: am I going to do more harm by not fixing it now?

Chris:

Your LSD is simply worn out,....:) If you didn't have an LSD, the opposite wheel would turn the other way when you rotate a wheel.

Its pretty simple to pull it out the side cover, unbolt the ring gear and have it rebuilt (after you drain the oil, of course).

You'll not do any harm by leaving it alone.

I would confirm model numbers, the car may have been delievered with an LSD but who knows what happeneds over time with different owners. I would be sure that it truely is an LSD before you go to the hassel of tearing it apart.

PorscheGuy79 makes a good point.... verify that it *should* have LSD first ...( first-things-first, huh?)...

Look for the -12 as stated earlier...

- wil