Monique

My personal opinion... the Quaife is good for drag racing. In a sport car, you need the plate type ala the Guard, Porsche type.

JasonAndreas

Has anyone here ever rebuilt a Porsche LSD? Is it possible to transplant just the 8 discs (4-inner & 4 outer) from the 964 to the 993 LSD? I priced out the replacement costs to rebuild (discs, seals, bolts) my 964 LSD and including the special tools, retail is a little over $400 (unless I forgot something). Retail on the inferior plate package for the 993 is over $600.

Ron

I thought Paul Guard sells the discs to replace the ones that came in the factory LSD units.

Terry Adams

I can't tell exactly when my original LSD wore out, but can we assume the 964 type lasts twice as long because it has twice as many discs? Even if it did, I would still go with the Guard unit. Already proven at the track, as I recall from previous threads.

Terry Adams

If he does, I would want to rebuild mine with twice as many discs as the original. Still looking at 2X a short life of a street-intended unit anyway. I'm still for the GB Guard unit.

Monique

After the "lateral thinker" threw a monkey wrench in the game, I chatted with Adrian Streather. He thinks the LSD fitted to the 964 (4 clutch plates instead of 2 in 993 LSD) will fit fine in the G50/20 etc gearboxes fitted to the 993's.

I will contact VB and Steve Weiner for further guidance. Then maybe Gert could get involved.

Will

I was going to install a Guard unit, but after talking to Brian Copans at BMC & G (Ohio, 513-779-3302), who is the factory authorized transmission guy for ALMS Porsches, I decided to follow his recommendation, which is to rebuild the factory LSD using Guard ramps and a Porsche Motorsport clutch pack. (Application: 100% DE car) I bought slightly used Guard ramps (60/40) for $300 and a new PMS clutch pack ($580) from him. If your LSD case is in good shape, it should only be another few hundred bucks to have this stuff installed, since it can be done without engine removal. If you're a racer who does enduros, he advised installing a transmission oil cooler, but for DE or sprint racing, a cooler is not necessary.

I'm picking up my car today, but I'll have to wait until April to give it a try on the track. You can see why in the photo below.

KOAN

I like the paint "accent" you have added to that beautiful RS clone. I expect to see a lot of the rear view as you pass me, with the new LSD ;-)

JasonAndreas

I've had the transmission open/slightly apart before (it was on the ground and I couldn't help myself from looking inside) and it wasn't a big deal but it will be interesting to hear from someone that has actually rebuilt an LSD. I can pull my LSD out of the transmission next week and if it fails the torque wrench test I will take it apart and document the procedure step-by-step with photos. The instructions in the workshop manuals look very simple, nothing anyone with even minor experience couldn't handle in their living room. (famous last words)

Terry Adams

Thanks Monique for doing the leg work on this, and Jason for your inputs. I am hoping that the proposed Guard unit has sufficient labor savings included, ie it would have cost me to assemble the separately supplied ramps and clutch packs into my existing OEM LSD.

Monique

Hello Jason,

The statement coming from you means most mortals should not try it out.

Apparently, changing the clutch plates is easy. Dixit a reputed Belgian racer I know.

Adrian and Steve W think the 964 LSD is a good fit. Awaiting VB's take... then we see where we want to go... but at equal proce, me thinks I'd go Guard. But then they have to aswer my phone calls or emails.

Monique

Update: Sent another email to Guard this morning.

I hope they call me soon.

kahuna

Are you guys sure that the 964 lsd has 4 plates? I was under the impression that they were all 2 plates from around 1984 , except for the motorsport lsds used in RS and turbos.

Monique

Hello Kahuna,

Asked the question from a specialist a few moments ago. Stay posted.

For Jason,

I considered the option of rebuild but abandonned the thought after I was told 8 hours labor plus $700 for the plates. Apparently the snag is setting the torque correctly...

If we can get a drop in unit for equal or less money than parts + labor.. aren't we winners? Asked a specialist for a quote on the Porsche Motorsport unit... problem is that Motorsport are closed till next week.

It ain't over til the fat lady sings!

JasonAndreas

The Workshop manuals and the PET cd show the original 40% locking 964 LSD with 4 plates (2 inner & 2 outer) and the 20-100% LSD having 8 plates (4 inner & 4 outer).

Any ideas on what is difficult to torque correctly? I don't see anything in the manuals and if we are only replacing the discs there is no need to readjust the drive set (ring gear, drive pinion and/or circumferential backlash -- best I can tell). If you replace the factory LSD with a Guard LSD and that uses it's own housing you will need to readjust the ring gear (maybe that is where the 8 hours is coming from?) I will PM Chris Cervelli, if VB hasn't done this I think he (CC) is the only person that posts here regularly that has actually taken a transmission/LSD apart (I don't know how often R.Deman comes here).

Before I order anything I am going to remove my LSD from the transmission case and test it the proper way. If it won't hold torque than I will probably measure the clearance inside the casing and decide from there.