Jack

Looking to accumulate data on this issue.... I've personally witnessed 4 GT3's suffer a crank pulley failure at track events -- the locking pin breaks and the nut securing the pulley comes loose. Pulley comes off, no water pump, power steering etc.. As a side note, all of these GT3's have had the LWF installed.

Anyone else seen or heard of this issue?

Z06

Missed shift's at or over 9000rpm.

roberga

+1 Z06. The only one I have witnessed.

JMeager

I knew of a 996 GT3 Mk1 that suffered the crank pulley coming loose. Cost the crank as it ate the crank end... very expensive failure....

Jack

None of the guys fessed up to a missed shift.....????

mooty

jack, this is my VERY WILD guess. bear with me.

i was told that GT3 and RS had different crank pulleys. i believe RS has steel and GT3 has alum. i dont know why they are different. would it be something to do with harmonic vibration such that LWF needs steel pulley while GT3 flywheel needs alum pulley?

again, i dont know what i am babbling about. but it is rather interesting that all the cars with this prob are GT3 with LWF. LWF is a factory part so it's just like RS. if the logic follows so far, then the only variable is the material of the pulley???

sharkster

You are correct. There are two different ones. Early ones had two holes in them. Others have ones with many more.... They require different tools (me being one of them) to tighten them. At first I thought it was just different for the RS and 3 but it's not... Seems like early cars.

9 more GT3s with LWFs since December and notta a peep, knock on wood or a pulley I guess.

PogueMoHone

But have they been over revved yet?

It seems like that might be the root cause.

What happens if the RS is over revved, or are these better driven (empirical evidence?) and is part of what the extra $17K gets you?

Food for thought and analysis?

Certainly a topic worth monitoring (thanks Jack).

mooty

i see, more confusion....

sharkster

The GT3 ECU reads quite differently and doesn't show over-revs in the same fashion as a standard bosch motronic 7.8 (motorsport lol) but to make it even more confusing there is an RS owner that we also know of that had the same issue. He's in Florida and the PIWIS didn't show anything. The dealer warrantied it obviously. With the tools I've got at my disposal the cars I've scanned haven't but then locally there have only been two. Someobody mentioned that there was a TSB on the torque specs as well.

prysma997gt3

Folks,

I have my car at the dealer now for some regular maintenance. I mentioned this issue to the service manager but he said he checked on it and could not find any info (Danbury Porsche).

Would you please point me to the right thread so I can gather some info and give to him? The car is there so they my as well check on it, or re-torque the thing.

Thank you

Luiz

roberga

Maybe someone that has a race shop can ask them. The cup cars over rev and stay together.A Motec guy that supports ALMS said he sees Porsche over revs of 12K+ and the motor keeps going. What is the difference with their pulleys?

richardmacpherson

I have had this lwfw change done to my 997 GT3 and changed the pulley as well.

The technician advised that it was neceassary to avoid this problem and directed to do so by porsche.

Rgds,

Rick

spare tire

It happened to a friend of mine in Chicago and I am sure he didn't over rev. He does have a LWFW.It wasn't expensive to fix but it happened @ 8:15 a.m. in the first session so it cost him the track day.
I also have an RS LWFW and mine is a O.K..

mooty

are you in walnut creek?