For those new to the Tesla S and X, you may be on your first set of tires. What comes next is the inconvenient truth. You may not understand until you drive a few more thousand miles. For now, read on.
The rear suspension of these vehicles is largely not adjustable yet is very dynamic. Toe is the only factory adjustment. Camber is not, but camber does change with ride height. That is the camber angles and heights are interrelated. You find yourself being told you need tires and an alignment. Here we go.
Before working on your vehicle, the alignment tech tells the vehicle to change height. The vehicle goes through a dance and ends up somewhere in spec. We can guarantee that this height is never the same twice. It is close.. But inevitably not exactly the same each time. This is not a flaw but the reality that the vehicle has to be able to cope with ride height changes on uneven ground. Most road surfaces are in fact not even and thus it has to have a reasonable bit of height roll and variance that it can call “acceptable.” It should be a bit more repeatable on a flat surface like an alignment rack but there is a large tolerance there. In addition, what occurs on a flat rack will be different when it levels itself on uneven surfaces like your home driveway or work parking lot.
Planes and Automobiles
To define a plane, you only need 3 points. When you introduce the fourth point, you now have 4 separate planes or 4 solutions to the problem… A 4 wheel car is overconstrained. With real world road surfaces almost never being perfectly flat, how does the car handle these situations?
With 4 different possible planes, which one is correct? If you are getting confused, don’t worry so is the car. Things just need to be “close enough” for it to be happy. As a human you will see 4 sensors, one on each corner. How can we simplify 4 sensors into 3 points? Internally the rear sensors are averaged and treats their outputs as one. (generally speaking)
This variation in ride height or roll, heave or tilt plays a part in the geometry of the suspension. For the rear, more travel will result in more camber. Specifically if a car is tilted, one side is lower than the other and you end up with differing values on each corner. The stock suspension components are very repeatable and “not adjustable” as you have heard time and time again. Most of the variation comes down to the tolerances on the vehicle height, not actually from differences in the components. These height variations are driving the differences in cambers.
Countless Tesla owners have been not only to Tesla, but have been to 3rd party alignment shops and are begging service advisors to please help them. They get their car aligned not once, not twice but countless times. The end result is the same. Tire wear is so bad that you can’t believe it is that bad. Yet every time you hear the same “it is within spec.” Camber is “not adjustable.” While technically true, it is not the whole truth.
They may not be able to help you at first. But we can give you good advice. Instead of concentrating on the symptom, attack the cause first. Instead of measuring camber, find the flattest surface you can and measure from the ground to the lifting pads. If heights are different from left to right, you are probably on to the first issue you need addressed. Unfortunately it will require a Tesla service visit to perform, but get an SC appointment and ask them to calibrate the ride height. Tell them what you found and specifically have them level the car better left to right.
This could solve your left/right issue, but you still need to address the “more than optimal” overcamber in the rear for low or “normal” ride heights.
Lucky for you, MACSBOOST offers high quality parts that are all you need.
For first generation up to 2021 (AC rear drive motors) you need a camber arm kit.
MACSBOOST Tesla S X Camber arm set
For refresh 2021+ vehicles you need a palladium kit.
MACSBOOST Tesla S X Camber Kit 2021+ Palladium