TrackJunke

I looked up the options on my car and I have option 220 which says locking differential. And also 224 for ABD. Is the lock differential code actual the limited slip differential? Also, I was told at my last service that the car does not have a limited slip or it is completely worn out. I am not sure how they checked but I thought I had a limited slip obviously. Is this somthing that would wear out in 36k miles? If so, will it do any harm to drive it while it is worn out?

I also have the inferior fuel option on my car. What makes it different than the other cars? I changed the spark plugs and the ones I got for the car were different than the ones that came out so I figure that is one of them. Anything else?

Thanks

kary993

As I understand it they can lock down one wheel on one side and use a torque wrench on the other to determine if it is working. The other less reliable way is to spin the rear wheel and see if the other wheel moves or not, it should. Mine does not. Both of those scenarios are up on a lift BTW.

Are there any other possibilities to determine LSD failure?

Bill Verburg

The 993 lsd is notoriously weak and wears out quickly. Some apparantly had 4 friction discs as in the older transmissions but most only had 2 and the material was far less durable than that used in earlier tranmissions. If you rebuild be sure to use 4 of the plasma-sprayed variety which will last much longer.

An even better bet to to score a G50/31 assymetrical lockup trans from a motorsports model like the 993RS.

Coleman

if your diff it worn or not working, get it apart quick.. it could save you bank in the long term... I just had a Gaurds Transmission LSD instlled in mine.. the billet build quality is amazing compared to the stock unit...

Coleman.

chris walrod

Coleman, did you get your car back together? How is the fresh gearbox? I did see it all apart at Hergies, some time ago..

kary993

Coleman, is the Gaurds a Porsche motorsport like version with the ramp up and down?

Greg Fishman

He makes both. Clutch or Torque Sensing differential.

kary993

Greg, which one are you using?

Greg Fishman

I have a Guard Torque sensing diff. When I replace the steel synchros or another part that has worn out, we will change the diff to a motorsport clutch-type version.

TrackJunke

I jacked up my car and turned one wheel and the other turned in the opposite direction. Is this a sign of the diff being worn out? Is my "locking diff" just porsche's way to say limited slip?

993tt

Are you saying that something will break evetually if the LSD is worn out? If that's the case I don't understand why? As far as I can tell, it cannot get more "broken" than completely slipping. Or am I missing something here?

/Erik

TrackJunke

I was wondering the same thing??

Paul

The fibrous material of the stock 993 LSD friction discs will some times disintegrate entirely, migrating throughout the transmission, causing more serious problems than just a worn-out LSD. I don't hear about this too much, but occasionally.

flatair

Greg & anyone else,

I've always wondered, what's the pluses and minuses between a torque sensing and clutch type diff? I've always thought the torque sensing design was superior?

Brad

Greg Fishman

Torque sensing only works under acceleration, no lockup under braking. Benefit of the torque sensing is that they don't wear out as quickly as the clutch type as they are gear driven.

Clutch type has lockup under braking and you can tune the car for the optimum handling. Lockup under braking will cause more understeer so the car will need to be dialed in.
Here is a basic article regarding the types of diffs.
http://auto.howstuffworks.com/differential.htm