Originally Posted by corradoMR2
JoeZ, you might be right. I put on just the rear spacers and went for a spin tonight. Same problem
as the car vibrates slightly at highway speeds.
One thing I noticed when I removed the spacers yesterday before servicing the car at Lexus is they had an imprint of the rim
because the spacers are aluminum. (See pic) This "softness" may be what is messing up the ride. I suspect when I hand torqued the lugs, it takes one lug to be slightly more torqued than the other four to make a slightly deeper imprint in the spacer at that spot. This would result in a rotational axis that is not perfectly straight, creating a slight wobble, and hence the vibration.
My last attempt at this is find spacers made of steel and give it a shot...
Wow! I am totally surprised that it looks as though it really is a question of the spacer ending up not be the same in thickness all the way around. Even though I realized that was a possibility, I didn't actually think it was a strong likelihood. But your picture of the condition of the spacer certainly points the finger at that. I also am surprised that the aluminum would compress that much, but obviously it does. It probably is a soft grade of aluminum, and perhaps a stronger grade of aluminum would not have done this.
The same type of lathe that is used to resurface brake rotors might be able to get the spacers flat again, if there is a way to mount the space of the lathe. Then, a piece of hardened steel not nearly as thick as the spacer, cut to fit, would prevent this from happening. A sandwich of steel and aluminum, in other words. You would have to find a shop to cut the steel, which probably would not be difficult, but it would cost you a few bucks. And you would have to have the aluminum spacers reduced in thickness according, so that the resulting sandwich would not be too thick.
You know, I still struggle a little with the idea that the deformation could have been sufficiently different from one side to the other, to make an appreciable difference. Maybe so, but I also wonder if the five holes in the spacer are small enough such that there is no chance of the spacer itself going on off-center. And if there is no problem there, I also wonder if the virtual circle formed by the five holes is perfectly concentric with the spacer itself. To check that, you need only take careful measurements of the distance that each hole is, from the inner or outer edge of the spacer. The picture makes it kind of hard to tell, but it looks like maybe the five holes might not be properly centered on the center of the disc. It also looks as though a couple of the holes are enlarged and not perfectly round, i.e., the sort of thing that someone might have to do if the spacer did not fit exactly. If by chance that is the case, then the spacer might not be going on properly centered, and even if it is, the spacer itself will not be balanced if material has been removed from one side more than from the other side. If there is any chance of any issues of this sort, then I wonder if it would be possible to somehow stick the spacer to the wheel when doing the balancing, or otherwise balance the spacer separately from the wheel.
By the way, I just checked out the pictures of your car in the other thread, which I only now realized was there, and I have to say that your car is truly stunning.
Final thought: when the lug nuts are applied, they force the wheel into proper centering. The lug nuts are what does that, and until they are tightened down, there is some play in the wheel position. There is nothing that does the same thing for the spacers. If the holes in the spacer are not snug on the studs, such that the spacer can move, then it simply will not be balanced. If there is any chance of that, then you could try attaching the spacer to the back of the wheel using some double-stick carpet tape. It only has to hold the spacer until it is tightened. Once tightened, it isn't going anywhere.
Good luck with it.