Negative Camber in the Rear and Expensive Tires

[lolachampcar]

One of the long term test cars (Edmonds??) just found burned inside edges and toe OUT. Can someone that has received their car direct ship confirm how they are securing them for transport? I do not see any holes or hatches in the bumper in the back that indicate there is any type of tie down ring. I am beginning to suspect they are doing this by strapping the lower a-arms in the rear and cranking them back to anchor the car. If they are, perhaps they are pulling toe out during transport.

WRT the air suspension, you can set Low from Standard when stopped but the car will return to Standard as you pull away. The car will then move to Low at highway speeds.

I did a very quick check with a camber gage between Standard and Low. There was 0.6 degrees of camber gain which, in my case, means my car went from -2.2 to -2.8 degrees of camber when in the Low position. Please do not take those numbers as gospel as it was only a quick test. I realized (1) -2.2 was not going to fly so I had a problem and (2) there was nothing I could do about the camber gain thus the absolute number was not that important.

WRT toe, change in toe with suspension travel is called bump steer. Most suspensions have very little over the normal travel range (Standard to Low at highway speeds has to be considered normal) so I did not verify it on the alignment rack. I left just a small amount of toe in at Standard in case there was a change with ride height (as opposed to putting zero toe in the back).

 

[swegman]

I happened to be scheduled for an alignment check today at the Rockville Service Center and saw the Edmund article yesterday. I printed it out and gave it to the service center. When they checked my car, the toe was OUT on the rear wheels, as with the Edmunds car. I suspect it came that way from the factory, because before the alignment, the car would jump slightly to the left under hard acceleration, and it does not do that now. I have the Pilots on my P85.

 

[texex91]

Wondering, is there any info out there in regards to driving the airsuspension in the "low" setting that affects both camber and toe? Is it recommended to not drive the car in "low" due to more tire wear?

That's interesting.

Can one change the auto low over 55 or 65 while driving to standard?

 

[jerry33]

Can one change the auto low over 55 or 65 while driving to standard?

Perhaps, but it would go back to low right away. I've never tried it.

 

[lolachampcar]

I just checked the rears on my P85+ lowered a 1/2 inch with camber links. The inner most groove was 0.212" while the outer most groove was 0.220". In short, wear is within my ability to measure it at 2400 miles.

 

[Zextraterrestrial]

I just checked the rears on my P85+ lowered a 1/2 inch with camber links. The inner most groove was 0.212" while the outer most groove was 0.220". In short, wear is within my ability to measure it at 2400 miles.

but how is the far inner shoulder past the wear bars?

 

[lolachampcar]

wear is even across the tire (no inside shoulder wear)

 

[petermon]

dear lolachampcar,

we're getting a P85+ and want to follow you in adding longer camber links and setting slight toe-in (i prefer Ferrari-like squirrelyness) -- perhaps i missed it, but (1) where did you buy the .21" longer camber links and how much were they, and (2) were you able to persuade a tesla service center to install these, or did you have to find an outside alignment specialist, and how much did they charge?

thanks
petermon

 

[lolachampcar]

petermon
I drew up the links myself and had them cut from 1" stock. It takes about 1 1/2 hours to pull the original links, press out the bushings, press them into the replacement links then re-install the new links. I used strings to get toe close then the local alignment shop to do final toe. There is absolutely nothing special about MS' alignment with only toe to adjust in the rear. I simply got a five year alignment from the local TireKingdom for a few hundred bucks so I could get a quick before and after set of numbers. PM me and I can get you more info on links and get you contact info for another owner that has installed them.

There is plenty of toe adjustment available in MS for the longer links but I did run into one issue on the last car I did (P+). One side had plenty of adjustment while the other we could not get to come in. We ended up loosening the four bolts that retain the rear sub-frame at which time it "Popped" back into place. We then tightened the four bolts and the adjustment range was the same on both sides. The alignment tech said it is not uncommon.

Tesla Model S
Tesla Alignment

I hope this helps.
Bill

 

[cfOH]

Bill: Do you have any photos of what it took to adjust your rear subframe? I can't visualize how that would be done on the Model S.

 

[lolachampcar]

No photos but then none really needed. There are four studs that hang down with four nuts on them. We (the alignment tech and I) loosened the four at which point the residual stress released and the sub-frame rotated a small amount to straight. We then torqued the nuts and had equal toe adjustment range on both sides.

I remember seeing some pictures on one of the threads were a guy did his own sig P+ upgrade including replacing the subframe. The whole four point bushing style mounting system is clear in one of the pictures where the as removed sub-frame assembly with all bits still installed is sitting on the floor. It is a simple and elegant solution.

 

[lolachampcar]

Back by popular demand

 

[yobigd20]

Well, this thread hasn't been up to date with the recent developments, but I wanted to point out some updates from another thread.

Basically 2 things:

1) Tesla has release a new camber adjustment bolt to the service centers so that camber can now be adjusted
http://www.teslamotorsclub.com/show...e-Bad-The-Ugly?p=494599&viewfull=1#post494599

and

2) the Hunter alignment machines were programmed incorrectly for the Model S. so its possible any SC with this machine was not aligning the cars right at all.
http://www.teslamotorsclub.com/show...e-Bad-The-Ugly?p=495166&viewfull=1#post495166


Now I wonder if they are going to recall for alignments or release a TSB for those new bolts...

 

[lolachampcar]

YBD,
Can you shed some light on exactly what was off with the alignment specs?

The tech I worked with at the Dania Service Center had a good bit of experience. We did not spend a lot of time looking at the machine's specs concentrating instead on how the car was aligned and how that affected wear. He most certainly knew what he was doing and would not have allowed machine specs to drive him to do something like toe out in the rear (which will kill tires).


BTW, what does "Crippled Air Susp" actually mean?

 

[100thMonkey]

lolachampcar, do you have a sense if Edmunds is right and their is something giving/fatiguing from the high torque that is leading to the rear alignment going out after production? From the sounds of it there are several factors obscuring the issue, Camber, inaccurately calibrated alignment machines and/or something in the engineering knocking alignment out. Wonder if Tesla is taking the third likelihood seriously or if they already know about it and are just trying to avoid a massive and expensive recal/fix, involving eating a bunch of tires that have no MFG warranty for them to fall back on.

 

[yobigd20]

Can you shed some light on exactly what was off with the alignment specs?

per that other thread I linked, the vendor for the Hunter alignment machines at the service centers had programmed incorrect alignment specs for the Model S.

BTW, what does "Crippled Air Susp" actually mean?

v5.8 crippled the air suspension by the disabling it's lowering at highway speeds

 

[lolachampcar]

Thanks YBD.... I'm 5.8 speed lowering off as well.
My question on the alignment specs were aimed at what was not correct in the spec.

100th,
I'm going to go out on a limb here and guess that transit tie down was pulling the rears to toe out and there was/is no predelivery check to catch it. I'm reasonably certain that the cars were properly aligned leaving the factory (rear assembly built on a jig and then a thrust angle check once it is a attached to the car). The eccentric adjusters Tesla is using are industry standard and have been working well on many a car for many a year. I guess there could be something amiss with the torque spec but then we would have seen a service bulletin to check toe eccentric torque (which we have not). Again, just a guess.

Going back to the tire wear survey, my best guess is that Jerry's statement that camber is not a wear angle by itself but will magnify other wear angles (like toe out) is spot on. High negative camber on air cars puts more load on the inside shoulder. Lower profile stiffer sidewall tires increase this loading by not letting the contact patch comply as much with the road. Toss on top of this some toe out and you get 4K miles. As before, just my guess.

Lastly, I can not imagine any tire manufacturer would warranty any tire against wear the likes of which is occurring in a worst case on MS. It is obviously a car related and not tire related problem.

 

[Musterion]

I'm going to go out on a limb here and guess that transit tie down was pulling the rears to toe out and there was/is no predelivery check to catch it. I'm reasonably certain that the cars were properly aligned leaving the factory (rear assembly built on a jig and then a thrust angle check once it is a attached to the car).

My car was out of spec on camber and toe with documented uneven rear tire wear, but never saw a transit truck -- was a factory pickup. Photo and alignment here: Checked Alignment: The Good, The Bad, The Ugly - Page 16

 

[Kraken]

My car was out of spec on camber and toe with documented uneven rear tire wear, but never saw a transit truck -- was a factory pickup. Photo and alignment here: Checked Alignment: The Good, The Bad, The Ugly - Page 16

same

 

[lolachampcar]

Well, there goes that theory I was really really hoping they were not leaving the factory with toe out or somehow just "slipping" to toe out on both sides all by themselves.

Tesla really should step up to the plate and communicate on this issue. It is one thing to have an unexpected transport issue pull out alignment, quietly fix it and then move on. It is another to have cars leaving the factory with toe out in the rear or loose enough toe adjuster that the cars just "fall" out. I guess this backs up the posts were owners said the back was driving all over the place under acceleration and deceleration. The problem in those cases was determined to be something loose (which sounds an awful lot like toe flopping about). Did anyone have toe adjusters confirmed as being the culprit?