am searching for a 993 cab and have come across one with a 40% limited slip differential. Is this an optional extra and someone please explain the benefit , if any? Also does any one know if a rear seat delete is a Porsche genuine option?

 

Option 220, LSD in conjunction with ABD. Benefit is power is driven to both rear tires by load sensing. Also aids in braking stability as there is lock on decel. A good thing!

Rear seat delete is also a genuine Porsche option.

 

There was no 40% lsd offered on 993s

there were 25/65 by ZF and 25/65 by GKN and 40/65 by GKN. the latter was only available on the 993RS

 

How many miles are on the car? Unless it's a Porsche Motorsports diff, the plates may be shot.

 

Whats the life expectancy of the LSD? My car has 40k and 4 track events on it.

 

Short... mine has 45 K KMS and my LSD is shot. Will replace it with a Guard unit this winter as part of a multi process preventive maintenance. Apparently the Porsche Motorsport is also good but not as good as Guard... according to various gurus here.

I have been advised to stick with the 40% unit especially if you do not spend much time on the track.

 

Yes sadly I have seen many LSD cars with limited miles that were slipping. As mentioned before, the factory got REALLY cheap with the LSDs in the 993s, and the plates just wear out very fast. A rebuild kit is also like $900 IIRC, so you may as well put something in that isn't going to have the same issue again.

I have had EXCELLENT luck with the Guard LSDs Monique. You can't go wrong with that choice They are also adjustable (not too easy, but they are) lockup between braking and acceleration.

 

Actually, I don't think rear seat delete was a genuine option. Rear locking storage compartments was an option, though. It replaces the seats & seatbacks with locking storage bins. For legal reasons they couldn't just remove the seats, seatbacks & belts without ensuring it wasn't habitable, hence the big heavy bins.

Sorry to pick nits Chris

 

Mine has the ZF 25/65 in it but the friction discks are so worn that it acts more like an open diff. So I bought a Guard 40/60 to replace it.

 

I have option # 419: rear storage compartment instead of rear seats. The compartments do not lock - it uses the same ***** as the glove box in front, and has tie down hooks on top for bungee cords. It's a great option.

 

Thanks... got the same info from Steve Weiner. Why should I reinvent the "LSD" so to speak. My car had quite some track time b4 me. Still track it but less than PO.

 

Viper Bob installed the Gaurd LSD in my car. I gues I smoked it doing laps around my local route. I started to notice that my inside tire would spin under full throttle. Now that does not happen any more. It really help to keep the car pointed straight under WOT.

Not sure what the split is. Maybe Bob could chime in.

Tom

 

Tom's LSD was totally smoked with 35K miles. He has a LOT of HP and drives just a little hard. As he said, it was like driving an open diff on his car. Coming through a turn and applying power you could just get the inside wheel to spin. We installed the 40/60 unit as I recall that was also settable to 50/80 (requires removing the diff, but all the shims still are fine so not a trial and error process to reinstall). Tom has a lot of power, but is mostly on the street. After the diff, no issues at all. The car pulls hard coming out of the turns.

If you ever want to see a work of art, take a look at the Guard stuff. The units are incredible. The torque biasing diff is unreal. You almost just want to put it on a shelf in the living room instead of installing it in your car. Almost

 

The Guard lsd is indeed a work of art

 

Thanks for all your good advice