[syswizard]

I was driving along in automatic mode at 35 MPH when suddenly, out of the blue, there was this loud clunking/thunking sound.
I immediately pulled off to the side of the road.
Called the towing service. Car is now at my local shop which specializes in German autos.

Message center said: "Transm fault Poss. No R Gear Drive on Poss"
I've heard this fault code could be reset in many cases, but in my case I think that's not possible.
Has anyone heard of a PDK transmission failing in this manner ?
Car only has 15k miles on it.
From my research on the Porsche forums, there are indications that 2013/2014 boxster/cayman PDK trannies could have been problematic.
Boy, do I wish I had known this before I bought the car !

 

[Voyager6]

There were a couple reports of early PDks where reverse gear failed in cold weather due to an internal seal leaking. Other than that, it might be caused by low gear oil or low clutch oil. In the case mentioned, the time for reverse to engage got longer and longer.

A loud clunk makes me think something mechanical broke. Usually this is due to the clutch not releasing fast enough and both gear banks are engaged at the same time. That is usually catastrophic. The other would be if a shift fork caught reverse while going forward. Due to the design, reverse would go before a forward gear.



V6

 

[Noah Fect]

I was driving along in automatic mode at 35 MPH when suddenly, out of the blue, there was this loud clunking/thunking sound.
From my research on the Porsche forums, there are indications that 2013/2014 boxster/cayman PDK trannies could have been problematic.

What indications are those?

 

[ELP_JC]

Your description sounds like the transmission needs to be opened up to find out what broke. You didn't mention if it happened with a shift, but if not, sounds extremely odd. Also important are the car's accident and service histories (especially if bought used), including any 'tunes' that alter factory settings. Hopefully your car is clean, since it's under warranty. I've never heard of any PDK failure on a 981 either, so don't know where you got that from. Definitely an isolated incident. They failed a lot when DCTs came out in 2008 and 2009, but not 6 years later. And yes, nothing a 'reset' would fix IMO. The good news is Porsche doesn't open up transmissions, so you'd get a new one. Well, probably a refurbished one, but done at the factory, not by a dealer. But it's a major job, that unless a dealer has done it before, has the potential of creating other unrelated problems. Hope that's not the case. No much choice but to get it fixed. Best of luck, and please keep us posted.

 

[syswizard]

Thanks for the feedback guys. Well, the local dealer says the car's warranty expires in May 2018. However, there are other "rules" that govern the applicability of the warranty.
Does anyone know the "rules" ?
First thing the service manager asked was : "Who did you buy it from ?"
I told him an individual, but in actuality I went thru a broker....so I wonder if that is a disqualification ?

 

[syswizard]

What indications are those?

https://rennlist.com/forums/porsche...-2014-cayman-s-pdk-transmission-problems.html

 

[Noah Fect]

https://rennlist.com/forums/porsche...-2014-cayman-s-pdk-transmission-problems.html

2 reports in 4 years, got it.

 

[Voyager6]

I am not going to say the PDK is bulletproof (nothing is), but it had some issues and Porsche has fixed them over time. Early PDKs had an aluminum colored pan design that leaked and Porsche replaced the pan with the current black pan that solved the problem (and the revised pan is used for replacement on those transmissions as you change the pan to change filters). The Pan covers the clutch oil so loss of fluid, over time, leads to bad shift behavior or total failure.

The 9X1s have had the new pan since very early, if not day 1. It is easy enough to visually verify. It was the 9x7 PDKs that had the poor pan design. Also, handling or shipping damage could have resulted in the cooler tube leak, rather than a manufacturer defect. They come from a long way away. The GT4 manual transmission 3rd gear weld failure had several people getting a new MT that was messed up in shipping to the dealer and the owner had to wait on a 2nd one to be sent. Having seen the shipping container my 3.8L X51 engine came in, it was a steel frame covered in cardboard and I have not heard of transportation damage issues with engines.

FWIW, the 9x7 PDKs came with just one cooler and they suffered overheating issues on the track and went into limp home mode when too hot. Porsche added the second cooler to help that problem.

I also mentioned earlier that there was an oil seal issue that affected reverse engagement time when cold and that was fixed in production. This was an early 9x1 issue.

The ZF 7DT-45 PDK was originally designed for the 997 with the engine to the rear. When accelerating hard, the gear oil flows back and covers the differential well with oil. On a 981 or 987, with the transmission at the rear, under hard acceleration, the oil also moves back and away from the differential. I have heard of one report of differential failure due to lack of lubrication. I do not know if this was fixed or not. Many of the ends of the gears have grooves cut into them that help spray oil around the gearbox, keeping things lubricated. For a street car, this is not an issue and I am not sure it is an issue on the track if fluid levels are kept topped up.

V6

 

[geezer lawyer]

I have a 2015 Cayman GTS. It had this same issue at about 6,000 miles. Porsche NA told the dealer to pull it, send it back and they would replace under warranty. It should make no difference from whom you bought it as long as it's under warranty. No one but Porsche NA knows what happened, nor will they.

 

[ELP_JC]

Does anyone know the "rules"?

That's what I referred to on my previous post. If your car never had any 'tunes' or alterations potentially affecting the transmission, or wasn't involved in an accident or mishap that could have affected the transmission, you have nothing to worry about. Porsche can find out about the former with a DME download (which they always do for a claim like that), which includes number of launches, etc. And the latter with a simple inspection. As I mentioned, if your car is clean, no worries. And no, it doesn't matter who you bought your car from; only what has been done to the car, and that it's still under the 4-yr/50K-mile warranty. Good luck.

 

[syswizard]

2 reports in 4 years, got it.

Yeah, you are right....I blindly ran into that one.

 

[PCA1983]

Are you saying it's not under warranty, and Porsche won't cover it?

I was driving along in automatic mode at 35 MPH when suddenly, out of the blue, there was this loud clunking/thunking sound.
I immediately pulled off to the side of the road.
Called the towing service. Car is now at my local shop which specializes in German autos.
Message center said: "Transm fault Poss. No R Gear Drive on Poss"
I've heard this fault code could be reset in many cases, but in my case I think that's not possible.
Has anyone heard of a PDK transmission failing in this manner ?
Car only has 15k miles on it.
From my research on the Porsche forums, there are indications that 2013/2014 boxster/cayman PDK trannies could have been problematic.
Boy, do I wish I had known this before I bought the car !

 

[syswizard]

Are you saying it's not under warranty, and Porsche won't cover it?

No...I'm saying it's under the warranty period (till May 2018), but because of a prior "mishap", Porsche may not cover it.

 

[PCA1983]

Can you explain what you mean by "prior mishap"?

 

[syswizard]

"prior mishap": jumped a curb....ouch.

Well, the PDK failure was "false".....the problem was in a loose CV joint. Smartly, the boxster shut down the drive train quickly when this was detected.
Of course the diagnostic was ominous, but not the real problem. For 2 weeks, I was on the edge of my seat.....and looking at a potential $10k+ cost of repair.

What I learned from this:
1) Don't jump to conclusions
2) PDK transmissions after year 2012 don't fail, they just don't.
Any claim I would have submitted to PCNA would have been highly scrutinized.

The car is coming home today !!

 

[jsykes]

That is awesome to hear. I think everyone with a PDK was probably watching on the edge of their seat as much as you. Its also good to know that there may be other issues out there that manifest themselves as transmission issues, so its important to have a competent shop do the diagnosis.

Thanks for the update.

 

[syswizard]

If you remember Dorothy from the Wizard of Oz...."There is no place like Kansas, There is no place like Kansas, There is no place like Kansas..."

Repeat after me: "PDK's after 2012 don't fail, PDK's after 2012 don't fail, PDK's after 2012 don't fail...."

There is no question Porsche has made the latest PDK transmission the new hurdle for other manufacturers to beat.......it's likely the most sophisticated transmission in production. In the electro-mechanical engineering world...it should be in the top 10....no question about it.
Top 10 Engineering Wonders of The Modern World

 

[Noah Fect]

1) Don't jump to conclusions

Usually a good plan.

2) PDK transmissions after year 2012 don't fail, they just don't.

Well, there have certainly been a few PDK failures (geezer lawyer's post above, for example), but nowhere near enough to suggest that 981/991 or even 987/997 transmissions from any particular model year have frequent problems or widespread defects. Glad yours wasn't among the exceptions!

 

[geezer lawyer]

I'm here to tell you that post 2012 Caymans have catastrophic failures with PDK since my 2015 GTS had one.

 

[syswizard]

I'm here to tell you that post 2012 Caymans have catastrophic failures with PDK since my 2015 GTS had one.

Yes but that's an entirely different PDK transmission, correct ?
It seems like Porsche just loves to create new product numbers and it's difficult to discern what are the differences between the models.
For instance, when I was looking for a used PDK, there were a ton of 981 "S" model transmissions.
But no one could tell me if I could interchange it with my base model.
So the question is: does the failure rate vary between sub-models ?