I have a new set of 37" KM3s on mine. I had the rears rebalanced twice with the Roadforce Analyzer, still didn't fix the problem. One of the rears was out of round. They put on a new one for me - no issues since. The dealer returned the bad one to the distributor as defective. I wouldn't take any large tires to a shop without that machine, since it allows the tech to measure high spots in the tire that will cause a problem even if it is "balanced".