terrysteer

Does anyone know if there is an LSD option for the 996, specifically whether there will be one on the 2002 model?

thanks

terry

Terry's 911 page

DJ

Someone will certainly correct me if I'm wrong, but... No, you can't get LSD. It was available in '99, maybe in '00, but no more.

Cupcar

PSM (stability management) is not compatible with a coventional LSD, hence conventional LSD deleted when PSM introduced. The reason is that the PSM works by applying individual wheel brakes to stabilize the car, this would be confounded by a conventional LSD. You can buy LSD for early 996 and install but you will have to deactivate the PSM.

Mike Schuster

Cupcar,
I believe the Corvette uses both an LSD and an active handling system, so I don't think these systems are fundamentally incompatible. I do think there may be other reasons. First, dropping the LSD is a cost savings. Second, on the street, PSM seems sufficient for reasonable balance without LSD. And finally, the 996 MY99 LSD is a chinsy 2 plate plus 2 spacer design that wears out rapidly.
Mike

Cupcar

Mike- Good point about the Corvette. My information is from a factory Porsche service book: "Service Information Technical Introduction Model Year 2001 911 Turbo", part number PNA 488 120. In this book on page 3-1 in the Manual Transmision section it has a note that says: "The Porsche Stability Management system (PSM) is standard equipment on the new 911 Turbo. As a mechanical locking differential would have an adverse effect on the PSM system, the 911 Turbo cannot be equipped with a locking differential". I assumed this was the case with all Porsches as PSM appeared as LSD's dissappeared. Interesting that the LSD was so chinsy anyway. Too bad the 911 didn't come with the G50 based gearbox and LSD the GT3 did.

SleepRM3

This is disconcerting? Mike, my old '93 Mazda Rx7 Twin Turbo (Type FD) came with a Torsen limited slip, and I never had problems with it, except for changing the diff fluid once a year? My current '97 E36 M3/4-door also has a variable locking/limited slip diff, and needs no other maintenance except for diff fluid changes.

Are you saying that if I go with a '99 996 with P72 option code (220, 222, 224--locking diff, anti-slip, active braking diff) that I'll need to replace the diff clutches on a regular basis? How often, and how much $$??!!

10 GT3

Torsion and cone types are not the same as clutch-type diffs. I had a Miata with the torsion and it actually does not lock like a clutch type. Everyone who has owned a Mustang 5.0L knows about clutch diffs and their wearing out. You won't get 100K miles on a clutch diff without needing to change the clutches. You don't actually replace the differential, just the clutch pack which comes as a service kit.

They are designed to wear just as brake or clutch linings do. The difference from brakes or clutches, when they start wearing it isn't as noticeable since the diff still functions; just more as an open diff than a locking one.

1999Porsche911

The LSD is very durable and mine continues to work as new even after 55,000 miles of hard driving. It is not common for needing any other maintenance other than lube change.

10 GT3

Terry,

There was no LSD option for the 996 in the US in 2002. It is a load of BS for anyone to say that the LSD is incompatible with PSM. All 2004 40th Anniversary Jahre editions had both mechanical limited slip differentials(only 20%/40% locking) and PSM standard. What's more, the LSD has continually been an option in Europe and is so today (check out the options on the UK or Germany Porsche sites). It just hasn't been optional for the US market.

Alan C.

I was told by Brian Copan that he could put an LSD in my 02 if I wanted one.

cooz

i beleive cupcar is correct that there has been no LSD option on 996 cars since/because of PSM. this is also true of 997 cars, except new 997 turbo which also has PSM standard does have option now for "LOCKING DIFFERENTIAL". they are not calling it LSD.

more to come

cooz
aka
norm mandell

10 GT3

FYI,

Keep in mind PSM is standard on all 997's. Here it is quoted from the 997 option list of the Porsche UK site as part of the sport suspension option:

10 GT3

Here it is in German off the Porsche Germany website:

vove

Yeah, its also on the 997 GT3 too. What a way to ruin a thorough bred.

SleepRM3

US-market 996 owners (except for the '99 996 owners) aren't real "drivers" LOL
Good to know. Thanks!