88 Club Sport

On my first DE with my new to me GT3 (https://rennlist.com/forums/showthre...ferrerid=80597) I lost the ability to shift. No slippage but one could not get into gear or change gear when the motor was running.

Yesterday it went to Velocity Motorsports to remove the tranny and figure out what happened. On the way back from the airport today I stopped by and when I walked in I heard “Oh oh, Craig’s here”. Not generally a sign of good news.

It appears that at some point in time one of the tabs had broken (pic 1 and 2). With everything being operational, the car was driven not knowing that the broken tab was flying around and digging into the bell housing……..deep gouging (pic 3). Clutch, pressure plate, flywheel, bell housing…..toast! This will not be your normal $2500 clutch job.

Here is the plan:
1. Replace the bell housing since this one is not usable with a 6GT3 Cup housing…..it’s a few bucks cheaper (?) and better (reinforced in places etc). Gbox has one waiting with my name on it.
2. I can either put back my toast diff into the Cup housing or address that at the same time. I think we will go with a 7GT3 Cup diff. It is adjustable and Stan (Gbox) believes it to be the best alternative out there for a track car.
3. Replace the Sport Sachs clutch with a MUCH better 996 GT3 Cup unit. Way better suited for track abuse than the Sport one that failed.

Sorry for the crappy phone pics but they make the point I guess.

I need a Martini……or two !

FFaust

It sucks, but at least your car is still the best looking one out there

85Gold

Cup car clutches are like a light switch not street friendly at all. Just a FYI from someone who had 1 in a 6GT3 as an emergency replacement.

Peter

FFaust

Not sure if you mean a puck clutch, which is what I have. It's fine, really.

Only thing is, and I don't know why, but I start to sweat like a pig if I see a red light coming at the top of an incline

Serge944

Don't install a cup clutch. Just go with one from the 4.0 RS - that one should put up with any abuse you throw at it.

Sucks that this happened to you so soon into your ownership. But, it's not the end of the world. Looking forward to seeing it back on track!

4porsh

LOLs, me too.
I have cup clutch and it can be done, but driving around town is work.

mooty

only idiots put cup car clutch in a street driven car. you will burn it out just exiting your driveway . that's why cups are usually winched or pushed into the trailer.

C2 Turbo

88 Club Sport

Ok.....I'll stop by the shop today and talk more about the clutch, I might have misunderstood them when we talked yesterday. The last thing I want to be is "stupid".....right Motty

007DT

I can't believe this...

When my clutch went out on my race car I was on the track and suddenly couldn't put it in gear. It ended up that the bolts backed out of the flywheel.. No consequential damage beyond the clutch needing replaced but I thought it was so odd that it just stopped like that.

My experience has always been that the clutch would slip or that there was warning or signs of wear.

I hate this...

88 Club Sport

This falls into the "**** happens" category Dave. The damage to the bellhousing has probably been going on for some time but no one would have known of the broken tab becasue the clutch opperated fine while the damage was being done. We will never know what the trigger was for the damaged tab. It will come back stronger and ready for more track time!

996FLT6

Had lite scratches on mine when mine grenaded. I take it bell housing is not reparable with that gouching huh? Mike

onefastviking

Well actually....... we probably can figure out what and why it happened. The tab, more commonly known as a pressure plate "drive strap" fails because it is made by design to handle a force mainly in one direction. They typically will fail on cars with lightweight flywheels, sticky tires, and sticky clutch discs. All these items combined with a missed shift, hard engine braking, using a dyno brake to load the car too hard, will all cause the strap to be pushed rather than pulled and then cause a very short time later the strap or rivet to fail. Since the car is new to you it may have been a previous owner issue, or maybe you remember a missed shift or engine brake ? There are a few sources for stronger pressure plate straps and rivets although also going to a more stock clutch disc vs a higher performance one is actually another way to fix it, then the disc will slip vs bending and fatiguing the drive straps resulting in the buzz saw effect to your transmission bell housing.

On a side note, this is not just common to Porsche, BMW actually had many more frequent issues with this happening. There are probably some ex-M3 racers on here that will remember it happening to them.

Hope that helps you understand it a little better.

007DT

My M3 clutch is like my women.

Strapless.

FFaust

^ Excellent, thanks for that Viking. Every time I don't throttle-match perfectly on a heel-n-toe, I get that little shiver that says, "ooh, pressure plate didn't like that". Mind you, it almost never happen to ME (j/k)