'Crunch' sound and vibration from rear - dealer says it's normal
12-21-2016, 01:54 PM
#31
Instructor
Thread Starter
wow. Please update when you get the truck back. Two transfer cases is astonishing. I'm going to have my brakes done next month by my indy mechanic; I'll have him change the diff fluid also and see if it makes any difference.
12-22-2016, 01:27 AM
#33
Instructor
Thread Starter
Two transfer cases and no improvement. Why did two separate dealers both think the transfer case was the source of the issue? Hopefully they swap the diff and that solves the problem (or does the new fluid added during the diff swap actually solve the problem temporarily). Glad you have a CPO to cover you. Hopefully they gave you a decent loaner while you are waiting. Please update us when you learn more.
12-29-2016, 05:16 PM
#34
Rennlist Member
Latest update....dealer decided that it was the differential (and that I was right all along). New diff put in, four wheel alignment and presto, no more vibration. The CPO covered over $10k in repairs, about half of which was actually needed. BTW, the change in fluid on the original diff did nothing.
12-29-2016, 06:22 PM
#35
Drifting
Latest update....dealer decided that it was the differential (and that I was right all along). New diff put in, four wheel alignment and presto, no more vibration. The CPO covered over $10k in repairs, about half of which was actually needed. BTW, the change in fluid on the original diff did nothing.
12-30-2016, 01:51 AM
#36
Instructor
Thread Starter
Thanks for updating. Glad the noise is gone and hopefully the fix is permanent. Does the paperwork from the dealer indicate what exactly was replaced? Thanks again.
05-13-2018, 07:08 AM
#38
Drifting
05-13-2018, 02:22 PM
#39
Rennlist Member
Just to add to this thread. What I originally thought was my transfer case turned out to be my front dif, which was replaced under warranty CPO, and all is fixed.
07-09-2018, 04:48 PM
#40
Racer
Just an FYI here from Oregon; friend and I have '12 CayenneTurbo's, both with PTV Plus and PDCC(for the record we don't think PDCC is involved in this noise issue). One CTT has ~89k, the other ~57k(57k truck is louder actually).....same symptoms; thudding/shuddering felt, mainly on slight left hand turn from a stoplight. Replicates itself daily at the same stoplights. Some days it might be quieter. It's FAR worse when driving up a steep uphill and turning sharply left to make an immediate U-turn. During this U-turn, one can hear/feel a loud friction sound from the LR. This sounds to us like the LR brake caliper is applying in order to allow the vehicle to turn sharper on itself(PTV+ is also providing more torque to the RR tire to spin the vehicle around quicker?). Which would follow suit in how PTV+ is supposed to work; https://www.porsche.com/middle-east/...plus-ptv-plus/
Would be interested to understand why there is usually no thudding/shuddering when turning right. Perhaps something to do with the length of the LR vs RR axles? The algorithms in Porsche control units are pretty tight lipped it seems.
No other issues noted, besides the annoying noises, which we've all learned to live with.
All in all, I assume these rigs had no noises when brand new? I can't believe Porsche would ok the PTV+ system to have such noises; "Buy a $150k rig, and you get free thudding noises!"
PS--very interesting to see CarGuyNVA have 3 repairs done, and the noise is still present.
https://rennlist.com/forums/cayenne-...l#post13813343
Would be interested to understand why there is usually no thudding/shuddering when turning right. Perhaps something to do with the length of the LR vs RR axles? The algorithms in Porsche control units are pretty tight lipped it seems.
No other issues noted, besides the annoying noises, which we've all learned to live with.
All in all, I assume these rigs had no noises when brand new? I can't believe Porsche would ok the PTV+ system to have such noises; "Buy a $150k rig, and you get free thudding noises!"
PS--very interesting to see CarGuyNVA have 3 repairs done, and the noise is still present.
https://rennlist.com/forums/cayenne-...l#post13813343
07-09-2018, 08:42 PM
#41
Rennlist Member
My Porsche Tech told me that these cars (All Porsches) start out quiet then develop noises and creaks over their life which they can't do anything about. It's a Porsche, drives like a bat out of hell and you'll just have to live with the little noises that it produces.
07-09-2018, 08:56 PM
#42
Racer
My Porsche Tech told me that these cars (All Porsches) start out quiet then develop noises and creaks over their life which they can't do anything about. It's a Porsche, drives like a bat out of hell and you'll just have to live with the little noises that it produces.
07-09-2018, 09:29 PM
#43
Drifting
No other issues noted, besides the annoying noises, which we've all learned to live with.
All in all, I assume these rigs had no noises when brand new? I can't believe Porsche would ok the PTV+ system to have such noises; "Buy a $150k rig, and you get free thudding noises!"
PS--very interesting to see CarGuyNVA have 3 repairs done, and the noise is still present.
https://rennlist.com/forums/cayenne-...l#post13813343
All in all, I assume these rigs had no noises when brand new? I can't believe Porsche would ok the PTV+ system to have such noises; "Buy a $150k rig, and you get free thudding noises!"
PS--very interesting to see CarGuyNVA have 3 repairs done, and the noise is still present.
https://rennlist.com/forums/cayenne-...l#post13813343
As for the reference above to “3 repairs done, and the noise is still present”, that is just not accurate. What actually occurred was 2 transfer case replacements (which originally was thought to be related to the rear diff “crunch” here in the forum...but turns out it’s not). The 3rd service was when I had the fluid replaced in the rear diff related specifically to that problem. I never took it in for 3 service visits related to the PTV+ diff. Again the other 2 service visits were for transfer case replacements, having nothing to do with the PTV+ diff noise.
Hope that clarifies things.
07-09-2018, 09:57 PM
#44
Racer
Greetings, CarGuyNVA here.....so let’s clarify this whole business. If you read my latest postings on this topic (in various threads), the specific problem with the PTV+ rear diff “crunch” noise was completely resolved, with only one service visit for that problem. A fluid change with the correct Porsche fluid specified for the PTV+ locking rear diff completely eliminated the noise/symptom. At the time I traded it on my Macan GTS 3 weeks ago, the PTV+ diff was still perfectly smooth and silent. Case closed.
As for the reference above to “3 repairs done, and the noise is still present”, that is just not accurate. What actually occurred was 2 transfer case replacements (which originally was thought to be related to the rear diff “crunch” here in the forum...but turns out it’s not). The 3rd service was when I had the fluid replaced in the rear diff related specifically to that problem. I never took it in for 3 service visits related to the PTV+ diff. Again the other 2 service visits were for transfer case replacements, having nothing to do with the PTV+ diff noise.
Hope that clarifies things.
Regarding 3 repairs done(I should have used the word operations, as 2 of them were reprogramming, not actual parts replacements/repairs), I was referencing the info you provided in post 23 above(12/14/16)--underlined/bolded below;
"Okay, I checked the dealer service records for my CTT and mine has had it all done....the ATI 3965 for transfer case replacement, the WC26 for 'recall - reprogrammed 4 wheel drive', and the WD-31 'reprogrammed rear diff control unit'.
And just like other owners in the thread from another forum I provided a link to earlier today, mine still makes the noise occasionally on slow tight left turns. It seems that more frequent rear diff fluid changes with the approved fluid keeps the symptom mostly under control, again as mentioned in the other thread. Even those that had their rear diffs completely replaced, the noise eventually returned (probably as the fluid aged?). It makes sense to me because as I've mentioned before, other vehicles I've owned with LSD/locking diff units have sometimes exhibited a similar condition which was often tamed with a fluid change using the correct fluid with the additive to specifically quiet and smooth operation of the LSD clutch packs. These additives do wear out. Something very similar going on here with the PTV setup I believe. Nature of the beast? I'll just have my dealer change the rear diff fluid next time I go in for an oil change."
I was under the impression this was still unresolved, as I hadn't clicked on your post #38 link yet. But now I see that your noise has been fixed with a rear diff fluid change using OEM Porsche fluid;
https://rennlist.com/forums/cayenne-...ferential.html
https://rennlist.com/forums/cayenne-...l#post15006017
Very glad to hear, and thanks very much for the info! We'll report back on our noises...
07-09-2018, 10:18 PM
#45
Drifting
Thanks for clarifying CarGuyNVA.
Regarding 3 repairs done(I should have used the word operations, as 2 of them were reprogramming, not actual parts replacements/repairs), I was referencing the info you provided in post 23 above(12/14/16)--underlined/bolded below;
"Okay, I checked the dealer service records for my CTT and mine has had it all done....the ATI 3965 for transfer case replacement, the WC26 for 'recall - reprogrammed 4 wheel drive', and the WD-31 'reprogrammed rear diff control unit'.
And just like other owners in the thread from another forum I provided a link to earlier today, mine still makes the noise occasionally on slow tight left turns. It seems that more frequent rear diff fluid changes with the approved fluid keeps the symptom mostly under control, again as mentioned in the other thread. Even those that had their rear diffs completely replaced, the noise eventually returned (probably as the fluid aged?). It makes sense to me because as I've mentioned before, other vehicles I've owned with LSD/locking diff units have sometimes exhibited a similar condition which was often tamed with a fluid change using the correct fluid with the additive to specifically quiet and smooth operation of the LSD clutch packs. These additives do wear out. Something very similar going on here with the PTV setup I believe. Nature of the beast? I'll just have my dealer change the rear diff fluid next time I go in for an oil change."
I was under the impression this was still unresolved, as I hadn't clicked on your post #38 link yet. But now I see that your noise has been fixed with a rear diff fluid change using OEM Porsche fluid;
https://rennlist.com/forums/cayenne-...ferential.html
https://rennlist.com/forums/cayenne-...l#post15006017
Very glad to hear, and thanks very much for the info! We'll report back on our noises...
Regarding 3 repairs done(I should have used the word operations, as 2 of them were reprogramming, not actual parts replacements/repairs), I was referencing the info you provided in post 23 above(12/14/16)--underlined/bolded below;
"Okay, I checked the dealer service records for my CTT and mine has had it all done....the ATI 3965 for transfer case replacement, the WC26 for 'recall - reprogrammed 4 wheel drive', and the WD-31 'reprogrammed rear diff control unit'.
And just like other owners in the thread from another forum I provided a link to earlier today, mine still makes the noise occasionally on slow tight left turns. It seems that more frequent rear diff fluid changes with the approved fluid keeps the symptom mostly under control, again as mentioned in the other thread. Even those that had their rear diffs completely replaced, the noise eventually returned (probably as the fluid aged?). It makes sense to me because as I've mentioned before, other vehicles I've owned with LSD/locking diff units have sometimes exhibited a similar condition which was often tamed with a fluid change using the correct fluid with the additive to specifically quiet and smooth operation of the LSD clutch packs. These additives do wear out. Something very similar going on here with the PTV setup I believe. Nature of the beast? I'll just have my dealer change the rear diff fluid next time I go in for an oil change."
I was under the impression this was still unresolved, as I hadn't clicked on your post #38 link yet. But now I see that your noise has been fixed with a rear diff fluid change using OEM Porsche fluid;
https://rennlist.com/forums/cayenne-...ferential.html
https://rennlist.com/forums/cayenne-...l#post15006017
Very glad to hear, and thanks very much for the info! We'll report back on our noises...