twitchett

Please correct me if I am wrong, but I used to see posts stating that the LSD wears out and requires rebuilding depending on the mileage. As much as I'd love to have the option on my sticker, if I felt I needed it wouldn't it be both cheaper and perhaps provide better performance to install a modern LSD? I'd consider it if I was an experienced driver or tracked my car.

I am not trying to de-value the option, but I am trying to understand if it is the rarity of the option or the added performance that people most value.

GC996

Most folks don't know the benefit of an LSD if they just drive around town and garage their car in the bad weather months. Many 996 came with PSM and without an LSD. Some even came without PSM and without an LSD.

However, IMHO, an LSD is critical in adding stability and safety to the rear end, on and off the track. The reason is that with an LSD, you have power going to both rear wheels. Without an LSD, you don't.

But it costs money. Hence a potential premium on cars with one.

Yes, like everything, it can wear out. I put a rebuilt guard on mine over 10 years ago. I drive it on the street and track. No problems. Works like new. But it cost me.

twitchett

Thank you so much for the explanation. I knew that it put power to both wheels, but I did not realize it would have functionality off the track. That's awesome!

My car has a never ending list of needs and wants and I guess I can add that one in there somewhere once I have refreshed all of the 23 year old factory parts.

plpete84

That's a great explanation. I think LSD is definitely a nice value add. Some Porsche buyers are real sticklers for originality so I suppose having a factory LSD is nice. What I'm curious about, as I genuinely don't know, is what actually wears out in the LSD. I know they have a different percentage lock under various conditions and require fluid changes with LSD additive to function properly. I just did this on my 40th - super easy job.

GC996

​​​​​​if you drive slow around town it certainly is a wasted item. However, you will notice the difference in bad weather, playing around in the snow, hot ******* thru a turn locally.

Regardless, most folks have never been thru any driver training with their car and therefore don't truly know how to control and drive their car on and off the track. Further, they don't know the limits of their car in braking, turning, etc. So most won't notice a difference.

This is why we see so many accident videos on YouTube with high end cars. The classic phrase, "more money than brains" is fitting.

GC996

Guard may have info on their website. Unfortunately, I can't give you a solid engineering explanation. Certainly someone else can.

twitchett

This explains my car's tendency to throw its rear into the next lane if you go WOT in cold/damp conditions. No rolling burnouts for me I guess

zbomb

Porsche factory LSD’s, Guard and OS Giken are plate LSDs that use friction plates to achieve lockup (similar to a clutch for manual trans).

The friction materials, number and stacking of plates contribute to the aggressiveness of the lock up.

The plates friction material sheds over time and their ability to lock up reduces, the replacement of the plates and friction discs are what is generally done to recondition.

GC996

Yeah, tires are a critical consideration as well. Wrong tires in the wrong conditions at the wrong temperatures with the wrong air pressure can create a boat loads of problems in addition. We can spend hours on that topic.

Flat6 Innovations

What's under your decklid is responsible for that :-)

twitchett

Haha you're absolutely correct! Perfect amount of power for the little car.

SRMPDX

You would think if they were trying to get $65k for a 996 they'd at least have a professional detailer correct the swirls in the paint, and maybe spend $60 on a replacement LCD for the climate control.

JBSL

I get folks wanting to make a couple bucks flipping the 996, but damn it's getting old.

Mike Murphy

When people bought these cars new, the LSD was probably good enough and wouldn’t wear out in time for the warranty to expire. I’m guessing the performance was the main reason people added the option, but now 21 years later, LSD is going to be a rarity thing…and the LSD is probably worn out.

LSD also helps with threshold braking in these cars with adding stability to help to prevent the rear end from wandering.

GC996

Absolutely. Better to have 2 rear wheel firmly planted versus one. Haven't seen the stats, but conversations I have had suggest that the vast majority of 996s came without LSD. Maybe someone has the actual stats.

Most don't even know they don't have one. I thought I had one, but later found out I didn't. Then it clicked at the track as I was getter faster and my inside rear wheel kept spinning when I would get on the gas and I wasn't gaining any speed. Guys were asking me why I was taking a couple of turns slower and I had no answer since I was on the gas early enough but not gaining any speed. Simple as adding a LSD to fix the problem. It may be the single best upgrade I put on the car for speed, stability and handling.