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-   -   How reliable do you think PDK trannies will be? (https://rennlist.com/forums/991-gt3-gt3rs-gt2rs-and-911r/785881-how-reliable-do-you-think-pdk-trannies-will-be.html)

ethel19 11-12-2013 02:18 AM

How reliable do you think PDK trannies will be?
 
When I got my 997 GT3.2 one of the thoughts I had in my head was that my manual trannie just might be more reliable in the long run than a PDK, ect.
After having many cars over the years that had hundreds of thousands of miles on their manual trannies with no problems whatsoever I thought it was the way to go. Well with about 15,000 miles on my car the car started to pop out of second gear all on it's own. The dealer was great and pulled the trannie out and put in a new "kit" they said even thought they admitted that neither they or Porsche knew what was causing the problem. Now with 20,000 miles on the car the trannie is fine. No more popping out of second. Having said all that I must admit I was a bit saddened that this happened. Like I said I have NEVER had this happen or any other problem before despite many cars before this with manual 's only. How do you think that the new PDK will fare in the new GT3 and can anyone comment on if they have had any problems with past cars that have had a PDK before?

Mike in CA 11-12-2013 02:32 AM

In 4 years with my 1st generation PDK '09 Carrera S I had no issues whatsoever.

Macca 11-12-2013 04:17 AM

Issues with MT 911 is not unheard of. There were a few issues reported on this board for the 997 gen GT3s.

Quite honestly Porsches gearboxes haven't ever been "class leading" ever IMO.

Lets that the G50 units (and skip altogether the G15s that were dogleg 1st and never cooperated till warm and then needed care in shifting). The G50 unit suffers from weak synchros on 1/2/3 - much better feel than the G15 IMO but still not a perfect gearbox and not a box that can be rushed on the track.

The 996+ generation moved to cable shift which also robbed some feel from the box IMO. I found the 997 6 speed unit a bit "rubbery" compared to my 993 G50 with SSK.

The 991 7 speed gearbox when first launched was just all wrong so I'm told by many that own it. 7th is overdrive, too many ratios, not particularly precise are all the comments from owners so I have heard. Apparently they have improved it a bit (linkages) and I heard they have auto blip on change dowen feature - whats the point int hat?

tcsracing1 11-12-2013 04:36 AM

the PDK will surpass the 997 Manual gear box.

SamFromTX 11-12-2013 11:03 AM

I drove my 2013 C4S PDK car for 17,500 miles, of which about 3,500+ where track miles since I bought it in January of this year then I traded it in a couple of weeks ago, . Had zero issues with it. I realize you are inquiring about PDK-S but this is my only reference.

MaxLTV 11-12-2013 02:34 PM


Originally Posted by ethel19 (Post 10899162)
When I got my 997 GT3.2 one of the thoughts I had in my head was that my manual trannie just might be more reliable in the long run than a PDK, ect.
After having many cars over the years that had hundreds of thousands of miles on their manual trannies with no problems whatsoever I thought it was the way to go. Well with about 15,000 miles on my car the car started to pop out of second gear all on it's own. The dealer was great and pulled the trannie out and put in a new "kit" they said even thought they admitted that neither they or Porsche knew what was causing the problem. Now with 20,000 miles on the car the trannie is fine. No more popping out of second. Having said all that I must admit I was a bit saddened that this happened. Like I said I have NEVER had this happen or any other problem before despite many cars before this with manual 's only. How do you think that the new PDK will fare in the new GT3 and can anyone comment on if they have had any problems with past cars that have had a PDK before?

One thing to keep in mind is that making manual transmission reliable is actually a more difficult engineering task than ensuring reliability in automatic. Automatic has more consistent speed of shifting, more consistent force applied to moving parts, better controlled engine revs etc. So load characteristics are much better controlled within narrower range. It all results in higher reliability and longevity, all else being equal. Of course, all else is not really equal - auto transmissions have more parts that can fail. So it's tough to say which factor will "win", but with good design and absence of defects, automatic should be inherently more reliable and longer lasting.

Mike in CA 11-12-2013 05:04 PM

I hope I'm remembering this correctly, but the life expectancy of the PDK clutches is on the order of 200K miles. Also, I recall reading that Porsche has durability tested a PDK tranny for over 1000 launch control starts without failure.

aamersa 11-12-2013 05:19 PM

The pdk on my 991C2S was rock solid. It could take all the abuse from day one (forget sissy break in procedures) without any problems whatsoever. And when pdk transmissions do fail, it is generally early in their life well within the warranty period, so if you are in that unlucky 1% or less, at least your pocket won't pay.

It is my understanding that DCTs have an unlimited life expectancy and the clutch never needs to be replaced.

kosmo 11-12-2013 07:45 PM

I really dont think theres enough sampling. Only time will tell. However ive seen several cars go into limp mode at the track and ive seen a few transplants at the dealer. The problem us that the dealer doent knows the cause of the failure as they just ship the old ones back to porsche.

reidry 11-12-2013 08:13 PM


Originally Posted by kosmo (Post 10900940)
I really dont think theres enough sampling. Only time will tell. However ive seen several cars go into limp mode at the track and ive seen a few transplants at the dealer. The problem us that the dealer doent knows the cause of the failure as they just ship the old ones back to porsche.

PDK debuted commercially in '09 so there are units out of warranty, sky hasn't fallen yet. From my reading, as previously stated in this thread by another poster, those that die tend to die early in the warranty period.

Some have been due to sensors on the transmission and not the internals, others have been due to internals and true enough they just get shipped back to the mothership, one assumes for teardown and root cause analysis.

On the positive, there are a number of folks building PDK Cayman race cars so it appears that they can survive under track conditions.

As you say, time will tell the full story.

Ryan

ethel19 11-12-2013 08:16 PM


Originally Posted by MaxLTV (Post 10900186)
One thing to keep in mind is that making manual transmission reliable is actually a more difficult engineering task than ensuring reliability in automatic. Automatic has more consistent speed of shifting, more consistent force applied to moving parts, better controlled engine revs etc. So load characteristics are much better controlled within narrower range. It all results in higher reliability and longevity, all else being equal. Of course, all else is not really equal - auto transmissions have more parts that can fail. So it's tough to say which factor will "win", but with good design and absence of defects, automatic should be inherently more reliable and longer lasting.

MaxLTV-

This is a most interesting response. All my life I thought the exact reverse what what was true here. That manual trannies were always easier to build and more reliable! Go figure. Thanks to all for the different angles on this topic,
I've learned alot.
I had a 1999 Ferrari F355 F1. Had it for 5 years. It was always said that these trannies were a mess. Now I know that they were not DCT's. Not even close. But after nearly 30K miles I never had a problem with the trans or clutch or anything on the car for that matter.
Again thanks for all the responses.

john weires 11-12-2013 11:59 PM

Almost 30k miles on my 09 C2S with PDK and no problems.

ScottKelly911 11-13-2013 03:51 PM


Originally Posted by Mike in CA (Post 10900565)
I hope I'm remembering this correctly, but the life expectancy of the PDK clutches is on the order of 200K miles. Also, I recall reading that Porsche has durability tested a PDK tranny for over 1000 launch control starts without failure.

I'm not doubting the projected reliability of the PDK transmission. But your statement reminded me of when Porsche came out with the first Gen PCCB's and they were advertising them as brakes that will have super long life and last nearly forever. Shortly thereafter, they started cracking and they were pretty much forced to back away from the claims of the longevity of the PCCB's (particularly more evident on cars that were tracked). Time will tell how the PDK reliability is long term.

Mike in CA 11-13-2013 04:51 PM


Originally Posted by ScottKelly911 (Post 10902973)
I'm not doubting the projected reliability of the PDK transmission. But your statement reminded me of when Porsche came out with the first Gen PCCB's and they were advertising them as brakes that will have super long life and last nearly forever. Shortly thereafter, they started cracking and they were pretty much forced to back away from the claims of the longevity of the PCCB's (particularly more evident on cars that were tracked). Time will tell how the PDK reliability is long term.

I suppose it's wise to take all claims with a grain of salt. With PDK, at least, my personal experience was good.

kosmo 11-13-2013 04:53 PM

^^^ yeah but those PCCB sure are purdy.


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