[B-52Gunner]

I would start with a process of elimination. I would go back to stock wheels/tires (if you still have them) without spacers and try that for awhile. If there is no problem, then I would swap the stock wheels/tires out for your aftermarket ones (if you can without spacers) and try that for awhile. If there is still no problem, put the spacers back on. By doing this you should be able to find out the cause of the problem (if it is caused by one of those items).