997.1 Turbo - Gearbox/Transmission chatter & vibration

[jonjay]

Hi All,

Been a passive member for many years (owned quite a few Porsches now).
I purchased a really nice basalt black 997.1 Turbo in December 2019 from a very reputable dealer. Shortly after collection on the second outing I noticed a chatter/vibration coming down the transmission tunnel when in traffic.

I thought it was the flywheel and I reported the issue to the dealer as the car was in warranty. The pandemic hit and the car eventually got seen many many months later. They couldn't find an issue which I found very odd as it is easy to replicate. The car was returned to me and of course the problem was still very much present. In the troubleshooting process with the dealer and another independent we have replaced the clutch flywheel.

It happens when in first gear in traffic mainly. The video taken is just an extreme action on the clutch pedal to replicate the noise for troubleshooting. its very evident when driving normally especially in stop start traffic when in first gear and it doesn't happen once in 2nd gear onwards.

https://www.youtube.com/watch?v=tbKWdPu8cfQ

Any idea on what this noise could be? Its been plaguing the car for two years now and as a result I've hardly driven it (pandemic etc..). I would be very grateful for any advise into this!

The dealer is trying to tell me its consummate with the age of the car (2007, 53k miles). I think that its nonsense as the other 3 Porsches I had and my current 996 C4S have never ever had that issue. :?:

Thanks!

 

[NickHappy]

I'm in a 2007 turbo with 52k miles and there is nothing unusual happening to mine as you describe so it seems you do have an issue. It's difficult to pick up from the video what's happening but the dealer is talking tosh.

Where abouts are you based? As a decent recommendation may help you.

 

[jonjay]

Based in Essex - the car is currently with the dealer now.

If you turn the volume up you can hear the sound just after letting go of accelerator.

 

[IMI A]

Garage is talking nonsense as I expect they maybe know a gearbox rebuilds is £10k. The gearbox is very refined and smooth with no noise or gear chatter in any gear. It sounds like it may need a gearbox rebuild or a whole new clutch assembly not just flywheel. Speak to Sport and Classic thats where I would go for gearbox rebuild. Couldn't hear anything on vid TBH though. I'm in Herts so close happy to have listen if you're still not happy I've had one of these for 15 years :thumbs:

 

[infrasilver]

The first and easiest thing to replace was the flywheel but after that it sounds like it could be one of the input or output bearings? I would also mention diff lash and the input shaft itself could also cause the problem, (I had had this problem some years ago) either way once you have eliminated the flywheel it points to looking at the gearbox internals?

 

[jonjay]

Garage is talking nonsense as I expect they maybe know a gearbox rebuilds is £10k. The gearbox is very refined and smooth with no noise or gear chatter in any gear. It sounds like it may need a gearbox rebuild or a whole new clutch assembly not just flywheel. Speak to Sport and Classic thats where I would go for gearbox rebuild. Couldn't hear anything on vid TBH though. I'm in Herts so close happy to have listen if you're still not happy I've had one of these for 15 years :thumbs:

Here is another car with same issue: https://www.youtube.com/watch?v=NJbxxzqmhrk

it was taken to show me its normal when clearly both cars have similar issues.

I agree its something to do with gearbox or clutch. Unfortunately car isn't with me for me to show you as its still with the dealer.

 

[jonjay]

The first and easiest thing to replace was the flywheel but after that it sounds like it could be one of the input or output bearings? I would also mention diff lash and the input shaft itself could also cause the problem, (I had had this problem some years ago) either way once you have eliminated the flywheel it points to looking at the gearbox internals?

Great suggestions and will certainly mention them. When the flywheel was replace the whole clutch was inspected but I guess unless you replace everything it will be difficult to potentially see if there is play in something...I may be wrong.

 

[deMort]

I'm afraid i also struggled with the video .. i could hear a lot of creaking but not really the chatter .. it's a bit irrelevant though as its hard to diagnose from a noise .

Other than whats above then all i can offer is you have a front diff .. that has a prop shaft going to the gearbox .. these have a rubber doughnut which can crack .. it would be unusual but something to have a look at .

1st gear only and in stop start traffic .. mainly take off i assume .. hmm

The clue is there...

There's slack in something .. yup .. check the prop shaft with engine off by moving it by hand each way .. it might help locate it .

 

[IMI A]

I still can not hear anything in second vid that does not sound normal. If you'd like to compare pop down and have a listen to my 997 turbo at 9e. Its done 101k miles and no noises from gearbox in any gear that I can hear at all. Maybe ask your garage to get second opinion from a reputable indy that is close by? If its a reputable indy you're dealing with they'd not skimp on a gearbox rebuild if the car needs it in my view so who's the firm? The usual suspects like JZM, 9e do not even argue just whip out gearbox in a jiffy and send it off to Sport and Classic for a rebuild if its required. Happened to 9e on a low owner 30k 997.1 turbo a few years ago. 1st gear synchro worn (abused).