PDK Failure & Outcome Story
10-04-2018, 02:37 PM
#91
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I almost never drive the car in manual mode.
I used the coasting feature every day for almost three-years straight.
I drive like an old-man. I rarely drive above 5,000 or 6,000 rpm.
10-04-2018, 04:13 PM
#92
You'd have to do an experiment to prove it but heat is the enemy of everything on these cars. I guess i probably could have made a long answer short by saying that it would be easier for a PDK to live where it's never over 50F ambient but i've also seen some PDKs outlast others with way more abuse on them. I think that every now and again, the parts are just the tiniest bit out of tolerance which causes them to fail the calibration process and have to be returned. The calibration process addresses the pressure sensors, the clutches and the shift rods and when it sees a shift rod move too far out of range it freaks out and says NO WAY and then the box won't ever calibrate and has to go back.
10-04-2018, 06:16 PM
#93
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If special tools are needed to get inside them, how do performance shops install "Dodson" clutches in them, like for the 991.2 that went 8.80 in the 1/4?
Someone obviously knows how to beef them up that way, or is that a separate section from what needs to be explored?
Someone obviously knows how to beef them up that way, or is that a separate section from what needs to be explored?
10-04-2018, 07:06 PM
#94
Racer
thanks. at a loss of explaining these failures.... are you the first owner of the car?
10-04-2018, 07:34 PM
#95
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Originally Posted by Big Swole
If special tools are needed to get inside them, how do performance shops install "Dodson" clutches in them, like for the 991.2 that went 8.80 in the 1/4?
Someone obviously knows how to beef them up that way, or is that a separate section from what needs to be explored?
Someone obviously knows how to beef them up that way, or is that a separate section from what needs to be explored?
10-04-2018, 07:49 PM
#96
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The clutches are in a basket at one end of the bell housing where it mates to the motor. The valve body is the black plastic cover you see underneath your car and that's where the solenoids sit in fluid and the shift rods and gear stacks are in the middle section. It's quite easy to get to the clutches. I take that back; the clutches require the least amount of disassembly but they still need to be cut out and welded back in.
Thank you.
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davisw999 (07-17-2019)
10-05-2018, 12:58 AM
#98
For those thinking that a manual tranny would fix the problem.... it might... but just FYI the 991 manual tranny is actually a PDK tranny with a different clutch and an elaborate mechanism to map the gear shift inputs to the two-path (even/odd gears) shifting used by the PDK. If most of the PDK problems being reported happen to be in the clutch or auto-shifting mechanism then switching to a car with a manual tranny would help. Using a single transmission base for both allowed for a significant manufacturing cost savings of course.
But if it is in the core transmission and gearing section having problems then manual trannies will be having the same problems. The percentage of manual trannies out there are far fewer than automatic PDKs so maybe that is making for less reports. Dunno....
But if it is in the core transmission and gearing section having problems then manual trannies will be having the same problems. The percentage of manual trannies out there are far fewer than automatic PDKs so maybe that is making for less reports. Dunno....
10-05-2018, 01:42 AM
#99
Rennlist Member
It's interesting to note differences between drivers. I always drive in Sport, in Manual mode, with Auto Coast off, and cruise at 3000+ rpm. I have never ever driven my PDK Porsches in Automatic mode, or in Normal Sport Chrono, or with the coasting feature on and engine shutting off during stops. I use my 911 for sunny day blasts, PCA and other sports car events, and I drive it like I stole it. It's my 10th Porsche since 1970. It's a toy, a hobby and a passion, not a car. If I just wanted a car I'd buy a Prius...
10-05-2018, 01:46 AM
#100
Racer
It's interesting to note differences between drivers. I always drive in Sport, in Manual mode, with Auto Coast off, and cruise at 3000+ rpm. I have never ever driven my PDK Porsches in Automatic mode, or in Normal Sport Chrono, or with the coasting feature on and engine shutting off during stops. I use my 911 for sunny day blasts, PCA and other sports car events, and I drive it like I stole it. It's my 10th Porsche since 1970. It's a toy, a hobby and a passion, not a car. If I just wanted a car I'd buy a Prius...
10-05-2018, 02:07 AM
#101
Rennlist Member
10-05-2018, 02:22 AM
#102
Instructor
Hate to add to this...
BUT... I just had the EXACT same problem. I bought a CPO 2013 with 30k miles.. had it for 3 months and I started it, put it into Sport mode, then shifted into reverse when all hell (grinding) broke loose. At first I lost reverse, then had 3rd and 6th gear.. the car would limp forward. Then I turned the car off hoping it was some sort of ECU bug.. started back up, sort of went into reverse and then I heard more grinding and now the engine light went on. I had my car towed to Porsche Newport Beach where they said the reverse gear was shredded and fell into the regular forward gearbox and there was metal pieces in my tranny. I wasn't too worried since I had the CPO warranty.. but my goodness, they said $20K bill waived. It took them 1 day to swap the tranny and 5 days to get it so I was out of a car for a week. I verified it was a new and not refurbished tranny.
Maybe it's something in the water in Orange County
BUT... I just had the EXACT same problem. I bought a CPO 2013 with 30k miles.. had it for 3 months and I started it, put it into Sport mode, then shifted into reverse when all hell (grinding) broke loose. At first I lost reverse, then had 3rd and 6th gear.. the car would limp forward. Then I turned the car off hoping it was some sort of ECU bug.. started back up, sort of went into reverse and then I heard more grinding and now the engine light went on. I had my car towed to Porsche Newport Beach where they said the reverse gear was shredded and fell into the regular forward gearbox and there was metal pieces in my tranny. I wasn't too worried since I had the CPO warranty.. but my goodness, they said $20K bill waived. It took them 1 day to swap the tranny and 5 days to get it so I was out of a car for a week. I verified it was a new and not refurbished tranny.
Maybe it's something in the water in Orange County
10-05-2018, 03:24 AM
#103
Had mine replaced in the last weeks of my CPO. 2012.5 with 20K miles at the time. There was NO transmission functional issue and it worked perfectly, however it was a real task to duplicate as the issue was a clattering/shuddering that only happened in the first few seconds of driving (when starting the car for the first time of the day) and ONLY when driving uphill. My garage happens to be on a slight hill, so if I lived on a flat street I probably would have never even known the transmission had any issue. It was doing it since I got the car and who knows for how long before that, and who knows if it would have affected the life of the transmission or if the trans would work fine even with it. After the first few seconds of driving uphill, the issue disappeared and was find for the rest of the day (and again, without driving the car immediately up a hill after first starting it for the day, you'd have no idea it existed).
As one can imagine, it was extremely frustrating and hard to reproduce. I even thought to just live with it, but obviously paranoia set in. Finally, the stars aligned and I was fortunate enough to be directed to a dealer and excellent SA who happened to be located RIGHT at the bottom of a hill. When he called me with those magical words: "We were able to replicate the issue" I literally felt like I won the lottery and was running around like a madman in joy. They replaced it, and all is good.
I bought a Fidelity Platinum warranty good for 60 years and 60K miles anyway. Which is an excellent value considering the cost of the components on the car.
What I would like to now know is if Coasting has any affect on the transmissions lifespan (you'd think Porsche would engineer it to handle that with no issues), and how much Porsche covered in O/P's bill, though I assume he was asked not to share that info. I'm assuming over 50% at the very least, and most likely 60-75% or so.
Interesting. I imagine any PDK replacement would have this done automatically? I didn't know about this so didn't ask my dealer whether it was done. Clearly they're instructed to, and we can only hope the process is streamlined enough to ensure it happens regardless of whether we mention it.
Judging by how well priced my Fidelity Platinum plan is, for a car like a newer 911, I can imagine as reliability reports suggest; these issues are very rare and Porsche indeed stands by their products and parts.
That begs the question: Whether more shifting and/or coasting is worse, or leaving it in gear to engine brake and coast around at higher RPM's, or downshifting harder to engine brake coast at higher RPM's is technically worse for a transmission.
As one can imagine, it was extremely frustrating and hard to reproduce. I even thought to just live with it, but obviously paranoia set in. Finally, the stars aligned and I was fortunate enough to be directed to a dealer and excellent SA who happened to be located RIGHT at the bottom of a hill. When he called me with those magical words: "We were able to replicate the issue" I literally felt like I won the lottery and was running around like a madman in joy. They replaced it, and all is good.
I bought a Fidelity Platinum warranty good for 60 years and 60K miles anyway. Which is an excellent value considering the cost of the components on the car.
What I would like to now know is if Coasting has any affect on the transmissions lifespan (you'd think Porsche would engineer it to handle that with no issues), and how much Porsche covered in O/P's bill, though I assume he was asked not to share that info. I'm assuming over 50% at the very least, and most likely 60-75% or so.
Thanks for the information. I found the TSB. Maybe I'll mention this to my SA next time and see if I can proactively retrofit:
NHTSA ID: 10055043
TSB ID: TI-85-13
Porsche: a new type of vent line must be used, if pdk transmission needs replacing, and installed prior to new pdk transmission. model 2013-2014 911 carrera, 911 carrera s, 911 carrera 4, 911 carrera 4s.
NHTSA ID: 10055043
TSB ID: TI-85-13
Porsche: a new type of vent line must be used, if pdk transmission needs replacing, and installed prior to new pdk transmission. model 2013-2014 911 carrera, 911 carrera s, 911 carrera 4, 911 carrera 4s.
The most informative statistic, and the only one that could possibly be compiled by someone not employed by Porsche, would be a plot of extended-warranty prices normalized against MSRP over the last decade or so.
If PDK failures are occurring after factory warranty expiration at a ruinously-high rate and not being adequately addressed through goodwill, that will be reflected in extended-warranty prices. If it ever became a real problem, aftermarket companies would simply stop offering coverage on modern Porsches.
In other words, they are not going to sell you 3 years of coverage for $5000 if they think there's a 25% chance of a $20K repair bill in that period. My guess is they want the odds in their favor by 5x or more.
If PDK failures are occurring after factory warranty expiration at a ruinously-high rate and not being adequately addressed through goodwill, that will be reflected in extended-warranty prices. If it ever became a real problem, aftermarket companies would simply stop offering coverage on modern Porsches.
In other words, they are not going to sell you 3 years of coverage for $5000 if they think there's a 25% chance of a $20K repair bill in that period. My guess is they want the odds in their favor by 5x or more.
That begs the question: Whether more shifting and/or coasting is worse, or leaving it in gear to engine brake and coast around at higher RPM's, or downshifting harder to engine brake coast at higher RPM's is technically worse for a transmission.
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AM6007 (02-25-2022)
10-05-2018, 03:45 AM
#104
Burning Brakes
It's interesting to note differences between drivers. I always drive in Sport, in Manual mode, with Auto Coast off, and cruise at 3000+ rpm. I have never ever driven my PDK Porsches in Automatic mode, or in Normal Sport Chrono, or with the coasting feature on and engine shutting off during stops. I use my 911 for sunny day blasts, PCA and other sports car events, and I drive it like I stole it. It's my 10th Porsche since 1970. It's a toy, a hobby and a passion, not a car. If I just wanted a car I'd buy a Prius...
I am on my 4th 911 and they all have been my DDs. No PDK faults, however my previous 3 all where manuals.
10-05-2018, 08:01 AM
#105
If there is a weakness in a particular aspect they should not offer it as an option.