Appreciate your efforts. It would be interesting to have an accurate assessment of usage in the cars that failed. I never experienced a PTU failure in our 2012 FF before selling it last year with about 23,000 miles. I had driven it on track twice and used it in snowy winters. Drove it fast but never did hard starts or power launches (eg using PS). Not sure if there would be a correlation. I was also the second owner and bought it with 2,700 miles so I guess I wouldn’t know what the previous owner had done.
Great analysis and thanks for doing this. I do agree, the sample size is too small to be removing what right now seem to be outliers.
Thanks guys. Regarding usage, there is a lack of comprehensive data on this as you'd expect. Of the 18 recorded failures, we know that one was tracked and one was a special event rental. Anecdotally, Safe4Now (who works at Ferrari FW) has only ever seen 2 failures and one was from track abuse (I think there are photos on this thread of the shredded front tyres). Neither of those two is on my database (AFAIK). We've also had owners experience failures despite owning the cars from new, never touching Launch Control and only ever driving them sedately on the road. Seeing the failure mode of the PTU, I'd guess that putting the fork seals under high pressure is what causes the circlips to fail and burst a seal. Having said that, I wonder how much precision goes into the manufacture and QC of a circlip? The probability of failure may simply be down to the luck of whether your PTU has stronger or weaker circlips installed in it. EDIT: I just did a quick bit of reading on circlips or snap-rings and it seems that the majority of them are stamped from sheet metal. Furthermore, they are sided and incorrect installation will result in the clip trying to ride out of its retaining groove. So I'm guessing that it's also possible that the failed PTUs could have the circlip installed the wrong way round. Perhaps Martin could comment on this?
Very interesting! Thanks for this awesome analysis. So if the PTU fails, can u drive it in wetmode? What further damage can one do? Sent from my iPhone using Tapatalk
This reminds of that old saying about Detroit made cars, you didn't want to buy one that was built on a Monday.
Thanks Martin. May I ask if you have a view on why some circlips are failing and not others? I speculated as follows in an earlier post; Are the circlips used in the PTU of average quality or are they special? Does it matter if they're inserted the correct way around or not (I'm guessing high lateral loads but no rotational loads so maybe it doesn't matter in this application)? In your earlier posts you mentioned that the circlip retaining flange wasn't wide enough (now remedied in your upgraded forks) - although the design is flawed, why are some clips breaking but others aren't? Thanks again, Reg
Hi The circlips that we have removed both broken and complete do appear to be quite brittle, The normal small amount of elasticity in a circlip appears to have gone which has been felt when removing the old clips in comparison to new clips. The circlips don't appear to be anything special just normal pressed items. As for a correct orientation of the clip I was taught that the rougher side faces out, as to whether it makes much difference I don't know just good practice I suspect. The question why are some failing and not others is also unknown, The driver really doesn't have much impact on the actual gear changes only how often they are performed, I will however from now on make a note of how many times each car has selected each gear and see if there is a pattern. I'll also compare the maximum temperature of the gear oil and see if that has some baring on the matter. thanks Martin
Thanks Martin, that's really interesting info. Are you using a higher grade circlip in your rebuilds (do such things even exist?). If not, would you consider sourcing one which is heat resistant and therefore less likely to become brittle over time? If you're using the stock circlip and relying on the wider flange of the rengineered fork to retain it, presumably it could still fail if it becomes brittle? Thanks, Reg
About the circlips, if needed I can machine some tailored ones with increased section (for example) in the right material. They won't be pressed items but EDM cut as we already do for some special applications. My main job is aircraft engines toolings manufacturing and business is low thoses days with the Covid crisis, so I can take some time for that. If Martin and Simon are ok I can draw one draft and share with them about it. P.
That’s a great idea Altoria and thank you for offering your skills. I’m no metallurgist but I wonder if material selection could be as/more important than material thickness in this application? If you could manufacture a drop in replacement for the OEM circlips out of better materials then it could be used in both Simon and Martin’s PTU fixes. If the clip is thicker then it would only work in Martin’s fix as only their forks could be designed to accept the thicker clips whereas Simon is using the OEM forks.
The material would be 45SCD6 + heat treatment. Thickness can be increased and yes need tailored grooves in the forks; it is also possible to increase the section but not the thickness in order to keep the oem forks but less efficient imho.
Keep in mind that if its a fatigue failure of the circlip EDMing a replacement wouldn't be the best idea as there is a hefty fatigue knockdown associated with heat affected zone that EDM generates. You could certainly make that up by using a material with better fatigue properties, but without knowing what the originals were made of it would be difficult to insure you've made a better part. I also think its far more likely that the difference observed by martin in the brittleness of the clips would have been from manufacture, not something that happens in service. It would take temperatures above 500F to effect the heat treat of the steel and the PTU shouldn't be anywhere near that. Seems more likely that it was a bad batch, or poor process control to begin with. If you're going to go to all the work of pulling the PTU and rebuilding it, I think it would be worth replacing the forks anyway. It also sounds like there are probably multiple failure mechanisms. If all of these failures were just do to something as minor as a circlip failing, I have to imagine Ferrari would have updated the PTU to fix that sometime in its ~8 year life.
Both Chris (Simon Furlonger) and Martin (SS Autotech) have confirmed that all the failed PTUs they've seen have had failed seals. I told my service manager at my franchised dealer that there is now a fix available 'outside the network' and he confirmed that the most common cause of PTU failure is a seal failure inside the PTU. I agree that it seems odd that Ferrari have not updated the design or parts. Or perhaps they have and this is why we have fewer recorded Lusso failures on the board than FFs? I think (but can't be certain) that all of the Furlonger and Autotech repairs have been FFs. No Lussos.
Hi Guys ive been looking at getting a FF then spotted this, has anyone had the PTU removed? what did it cost? I want a FF for the V12 and 4 seats/folding rear seats just so i can use it like a normal car (and keep my 458 spider for fun days)
They can be rebuilt now for a fraction of replacement. If you go back several pages you'll find all the info you need.
Don't let this issue put you off buying an FF, They are fantastic cars and a very good everyday car. As G Pepper said they can be rebuilt now.
Dude this is exact what I have done FF for every day and 458 spider for fun days Sent from my SM-F916B using FerrariChat.com mobile app
To all There is again a new PTU victim. I got this in my email today on which i replied Hello. I am an owner of a 2017 GTC 4 Lusso. Owned the car for two years (12,000 miles on it – no longer under warranty). It was my everyday driver for first year then had to get second car due to problems. Car has, unfortunately, proven to be a reliability nightmare. Many problems with the PTU system and battery. If they do not buy it back from me, I may be forced to litigate with them. Read the thread you started on Ferrari chat. Curious to know how your lawsuit shaped up. Would appreciate any information you can share. Bart B. Hello Mr B.B., As you probably know lawsuits are time consuming and especially in Belgium, this case is still running. For the moment the judge appointed an expert to investigate if these problems are concept faults and if my car is fully repaired. I told the expert that there are concept faults in the PTU and that the PTU is under-dimensioned to cope with the big power load of a V12. For the moment I know around 20 cases with malfunctioning PTU’s. But there are many more, Ferrari has replaced a vast number of PTU’s under warrarnty of which we are not aware. Luckly for them most FF and Lusso’s have very low milage and are not up to a replacement yet. So once your car is out of warranty all cost are on your behalf, and I assume that these victims will start complaining. I am convinced that sooner or later this car will give problems with the PTU and certainly if you drive it in urban traffic. On the highway the PTU is not engaged so then the problem is not existed. You have read my chat on PTU problems regarding the LUsso, I assume you have seen that third party workshops have repaired PTU’s where Ferrari doesn’t. Ferrari asks around 30.000$ for a replacement of the PTU and they only swap it, they don’t repair it on site even tough it is possible And your swap is most probably a repair from another Lusso owner and this repair is still prone to malfunctioning. So even if you repair your car, am I quite sure your car will mal function again after approximately 15.000km. If I was you I would definitely litigate or you will end up with a very vulnerable car and a repeating repair cost on the PTU. My lawer Yvan Verfaille is reading this email I will ask him to send you copies of the summons and conclusions and the expert report when available. They are in Dutch but you can reasonable translate with google translate. Did you read my other thread : https://www.ferrarichat.com/forum/threads/recall-action-ptu-on-lusso-ff.626555/ What is the mileage of your car when the PTU failure occurred? Can you give a detailed info about the other problems on your car? b. rgds Frank vancauwenberghe
Hi ModenaChallenge i guess you have seen my previous post to mr B.B. I don't think the FF or Lusso is a good idee as a daily car. Altough it is a nice car to drive the PTU is just not made for daily driving. It is just to weak to cope with the hugh power force the V12 makes on the small gearbox. i would advise FF and Lusso owners to avoid urban trafic and use the car only in long distance trips. i assume you don't want a cost of 30.000$ every 15.000km and with the risk of damanging your engine. But if you don't care for the trouble and the money it is a fantastic car to own and drive. rgds
Frank, this 30K$ every 15KKm is made out of thin air and based on exactly no data at all. I would suggest taking it easy on that line, because making such assertions invalidates any points you might have - in my eyes, at least, because it makes it seem like you're either unfamiliar with concepts the of statistics, induction, and negating an implication, or you're irate beyond reason.
