pontiacgp said:
The reason why any wheel nut can loosen is the wheel expanding from heating up and stretching the stud then cooling down The thermal expansion rate of aluminum is far greater than that of steel and that's why the issue arises more often than with steel wheels. We use 1/2" studs on our race car and the wheels are tightened before it heads out for some test laps. When it comes back and we let it cool down in we always get a 1/4 turn or more out of each nut and that's on a steel wheel. The aluminum spacer does not compress, it expands and that could cause a problem if the wheel studs are not able to withstand the stretching. If you want to run a 1" aluminum spacer I would suggest to go to a 1/2" stud..and always use anti-seize no matter what stud your using
Sorry, but your logic is wrong. Let's consider your race car with steel studs and steel wheels. Your're suggesting that the looseness of the lugs is the result of thermal expansion? How is that possible when both the studs and the wheels are steel, so the expansion rate is exactly the same?
I wonder if the looseness you're seeing could be due the fact that you're using anti-seize lubricant on the studs?
The hub-centric spacers that I recommended are 2" thick. The spacers are counterbored so that the thickness clamped between the lug nut and the hub is no thicker than on stock aluminum wheels, thus there is NO additional load on the wheel studs. The fact that the spacers are hub centric means that the shear load of the wheel on the vehicle is carried by the hub, not the studs, just as it is with stock wheels. Ironically, using lug-centric aftermarket wheels will load the studs much more than using hub-centric wheel spacers.
By the way, the expansion rate of steel is 7.3 microinches per inch. The expansion rate of aluminum is 12.3 microinches per inch. Assuming that the hubs get approximately 400 degrees F hotter, and assuming that the clamping thickness is 0.5" (which is about what it is on the 2" spacers I have), the amount of differential in the growth of the aluminum spacer (or wheel) vs. the growth of the steel stud is a whopping 0.001". That's right, exactly one THOUSANDTH of an inch. Feel free to do the calculations yourself. Wanna bet that the factory torque on the stud puts waaaay more than that stress on the stud?
Math is your friend.