I bought a full new set of tires per the recommendation of my local mechanic, Ron Raimes automotive. The tires were again wearing heavily on the inside sidewalls in an unusual pattern as you can see in the picture below. The standard inside wear markers were not yet worn down. These set of tires are not nearly as bad as the last set, but they still did not wear very evenly.
When he looked at the alignment before installing the new tires, the alignment for both the toe and the camber were again out of spec. My mechanic suggested that he would install the tires, align them and then suggested I come back again in 1,000 miles to see if the tires would stay aligned.
Since Tesla had been quite responsive when I had alignment issues in the past after emailing them at the VP level, I decided to send them a note discussing this current state of alignment. Only 7,000 miles had passed since the Minneapolis center had adjusted my alignment again, so I was a bit concerned.
I took my car to the Sunnyvale service center and explained the entire saga. I had only driven my car 200 miles with these new tires. When they checked my alignment, the tires were again out of alignment. The alignment had shifted in those 200 miles but the vehicle measurements clearly show that the camber is out of alignment. A tire shop has no ability to adjust the camber. The camber in the rear was at -2.3 and -2.32 with the spec being between -1.4 to -2.1.
Because I had expected to wait at the service center, I did not bring my house key or garage door opener, and the car was driven 30 miles between the first 6/26 check by Tesla and the second set of numbers the next day when they did the alignment. I am a bit concerned about the amount of variability in the shift of the front toe. The front left shifted from -0.16 to -0.27 in 30 miles and the front right shifted from 0.07 to 0.31. I have included five sets of alignment data in the table below over the course of 250 miles. I am a little concerned that the alignment does not appear particularly stable although these numbers are quite small.
In both shops, I watched the alignment process. They use the same brand alignment machine, Hunter, which uses lasers to accurately check the alignment. As an odd side note, my summer job between junior and senior years of college was working with laser interferometers at Hewlett Packard, so I know these machines are very accurate.
My local garage did complain that the rear tires are physically difficult to align. The configuration of the car makes it quite difficult to get the mechanic’s arms in the correct place to adjust the alignment.
Sunnyvale Tesla in the end concluded the problem with my alignment was the camber bushings, which is the rubber part in the camber arm. They replaced both camber link arms with a newer upgraded version.
The new camber arms also have an improved design and a more complex shape that should support more torque than the original camber arms. I am hoping the challenges with alignment are completely solved, but I will have it check again by both my local mechanic and Tesla to ensure I can drive many miles with these new tires.