matt777

Hi John. It must be nice to find out the car already has upgrades! Did your LWF and clutch come with the TO bearing and bolts (they are different) ? You might be able to see if you have a LWF by looking through one of the openings with a mirror and flashlight. I have no idea why my gbx doesn't rattle but I'm not complaining. Perhaps its got something to do with the Motorsport shaft?

johnsjmc

The car also has a giac chip and FVD mufflers.,that the Po said nothing about.It has an old PCA sticker on the side window so it was muched loved by one of it,s previous owners.I got a new factory 964 LW flywheel ,pilot bearing, Sachs pressureplate ,disc and ring gear. No guide sleeve or throwout brg. All for $750. The throwout bearing and guide sleeve and bolts are readily available. The seller bought them for a GT2/3 but then changed his mind before installing them because of the rattle noise issue I think.. I hope the Sachs plate isn,t too stiff but it is described as similar to stock feel,less than the 999 motorsport number.

trophy

Hey John, If you find you already have a LWF in your car put me first on the list for the one you bought off Ebay.....

GTgears

I just wrote a long reply which the board promptly ate. What follows is the abbreviated version.

There isn't really any "typical" regear. Most guys don't have the budget for a $3500 mainshaft with 1&2. East coast tracks are faster than West coast tracks. Changes of 1/2" in tire diameter or 500rpm in redline/shift points have a substantial impact on things. Some have a sliptfit 2nd. Some don't. Sometimes we can work around 1 or 2 stock ratios, sometimes we can't. Sometimes the car is still street driven, sometimes it's always trailered and doesn't need a highway gear.

The G50/31 is a popular solution because it's a generalized box that can be run on most any track in the world and do reasonably well. It's not perfect if one is trying to optimize for a single track or event, but it's a good all arounder. There's a bunch of different ways to configure similar performing boxes based on various different needs of performance, application and budget. If I were to say one thing is typical for 993 regears it would be 3 or 4 gears. But each case really is different and is treated as such when we consult someone on what would be best for them.

johnsjmc

If I already have one then the new one is going in after the trouble to get at it. I need to replace my 1 st gear syncro and deal with the dragging clutch on the dry splines issue. If I have a LWF already then I will have a used setup available.

JasonAndreas

You might want to double-check that. The G50/32 syncros are different but the /31 uses the same as the /20, /21, etc. Nor is the LSD a Porsche Motorsports part.

Reddy Kilowatt

Comparing your speeds/revs to the info provided by Bill Verburg many times should offer you an easy way to determine what box you actually have, aside from just noting that it "grabs revs easily."

cohare

So it doesnt have steel syncros? Or LSD?

trophy

From what understood it had steel syncros on 3,4,5,6. Not sure of the LSD

matt777

I take the no stalling observation back It stalled 3 times tonight so I cranked up the idle to 900rpm (ISV). I'll test it out next outing providing the weather holds out. There is not alot of grip with the Sumis at 50F.

JM993

You made me look it up......

According to the PET, factory manual set and technical specifications book, the g50/31, 32 and 33 all use the same Porsche Motorsports 40/65 LSD.

You may be right about the syncros as I don't see difference in the PET. Perhaps Steve W or Bill V can verify.

Cheers,
Joe

Bill Verburg

Jason is correct wrt the syncros, only the /30 & /32 have the steel syncros and stronger shift fork

wrt lsd all the /3x come w/ the 40/65 which I believe is a 4 plate unit but I've never taken one apart either, it is certainly not the same lsd used in the /2x transmissions

johnsjmc

I know what box I have, it's a G50 20 with LSD. This car grabs revs as quickly as my 3.6 with light flywheel and alloy clutch did when installed in my 1980 SC.The grab revs is referring to the possible LWF. I can,t detect the telltale rattle but Matt says his newly installed LWF isn,t rattling.
I will need to dismantle to be certain and I am expecting to only find the stock clutch and flywheel. I already have a new LWF and a clutch sitting on the bench waiting for the time to install it.

GTgears

Yes, you have the motorsports LSD. In addition to the alternative locking factor, it's got the silver motorsports plates in it. That's why the "vane kit" for yours is $300 more than the standard carbon vane kit. The standard 993 carbon plates, while they bite well when new, wear more quickly than the motorsports plates and are often done by 50k mi or less.

trophy

Does anyone know if the rebuilding process for an LSD is something that could be a DIY, or does it have to be sent to someone like Matt at GT.

Also, does a 997 GT3.1 LSD work in our transmissions?