Bgoldey

My 06' Cayenne S with 3500 miles has started to drift/pull right (off crown) on roads it tracked straight when new. The dealer checked the alignment (scratched the frt rt wheel in the process) and says 6 seconds from lane center to right side is within spec. Again, 100 miles ago on the same roads it tracked perfectly. 19" P Zero Rossos. I've driven 911s/993s for 20+ years (still do) and most drift /pull problems has actually been a tire issue. I detailed the car the day prior to bringing it in and checked tire pressure 30 minutes before bringing it in. I know they did the wheel damage. Needless to say it has turned into a urinary olympics. Anyone experience alignment/tire issues that caused drift?

ltc

IIRC, back in the 'early' days, there was at least one TSB/update to the Cayenne alignment specs. I would have to imagine that your dealer has the latest alignment specs from PAG.

As for following the crown of the road, the official position is that all Cayennes will tend to fall off the crown and drift, but the degree to which they do is very subjective.

Normally tire related issues (i.e. lack of road force balancing) show up as vibration, not alignment.....at least as far as I can recall on this forum.

Other things to check might be suspension components (coils/PASM, rods, ball joints, etc) for free play....but again, I would have suspected that you would have noticed that in the steering prior to noticing an alignment induced drift.

Pyroproblem

The cayenne is a heavy vehicle (~ 6000 lbs) and will usually follow the slope of the road. It is very difficult if not impossible to completely eliminate this "drift"...
Ive tried many many different alignment settings to minimize the drift and while it works sometimes, it will not completely eliminate the drift. Ive tried swapping tires front to rear, left to right, etc. and sometimes it helps, sometimes it makes it worse...Usually when I align a Cayenne, I will put the right side about 1 degree more castor than the left while still staying in spec. This seems pretty effective from my experiences...

Bgoldey

Thanks for the info....Here's some more info ....I'm also starting to see premature wear on the outer edges of the two front tires which has me concerned. I took a nail to the right rear which was repaired by a reputable tire guy, but in the past I had some pull issues with my 911SC which I was told was caused by an internal failure within the tire itself, increasing rolling reistance and thus causing the pull....hmmm. I guess a opposite side rotation would address that theory. I polished out the micro scratches left by the dealer with a little light compound and some creative buffing so at least thats resolved...The dealer's "thats the way it is, just learn to like it" reminds me of the Secondary air injection worn valve guides after 40k miles fisaco I went through with my 993.

ltc

If you're seeing outer tire wear, camber is the first thing to come to mind. That should not be happening.
What equipment does your dealer use for alignment?
Ask them for the alignment specs.
When mine was aligned, actually any of my cars, I am always given a printout of actual vs target/spec.

Bgoldey

I'm going back to the dealer monday....anything else besides the printout and machine type? It sounds as those you doubt that a nail/repair could cause enough damage to significantly alter the tire? I contacted a very highly regarded socal independent shop (track, race, mod, repair shop, 993, 996,997 some Cayennes) who were very helpful and interested in helping me solve the problem. I can live with some drift but I don't want to trash a set of P-Zeros just because the dealer says everything is fine.

Bgoldey

And BTW thanks for your help!

ltc

Sorry, but I just can't understand why a nail/repair to the rear tire would cause both front tires to develop outside wear.

Have the indy get the updated alignment specs and put the Cayenne up on their rack.
Best of luck.

ltc

You're welcome.

As I burned all of my documentation/paperwork when 'that' vehicle was 'sold' (insert Forrest Gump: "and that's all I have to say about that"), I was able to find in this post
https://rennlist.com/forums/cayenne-955-957-2003-2010/181215-lateral-g-and-the-new-alignment-spec.html
the last alignment specs/updates I was aware of: (note: these are all targets)

Rear Camber: -1.33deg +/- 0.33deg max diff left/right
Rear Toe: 0.16deg +/- 0.08deg max diff left/right

Front Caster: 8.58deg +/- 0.5deg max diff left/right
Kingpin inclination: +10.75deg +/-0deg max diff left/right
Camber: -0.25deg +/-0.33deg max diff left/right
Toe: 0.08deg +0.08deg/-0.05deg max diff left/right

Bgoldey

I educated myself on alignment today and took a closer look at all tires. The outer edge of rt frt is worn more than the outer edge of the left frt. Both frts outer edges worn more than any other edge frt or back. Assuming the kingpin inclination is correct it sounds like the left frt has slightly too much positive camber and the rt frt has a greater amount of excessive positive camber (would that be too great of a differential? hmmm...), hence the wear and the pull. But what do I know? At least I'm more educated on the topic. I agree the abnormal tire wear dismisses any tire damage issues. I will report back.