I had new Yokohama Geolandar A/T-S tires installed on my Tundra and now I feel a vibration that wasn’t there or that I didn’t notice with the original tires. The Yokohama tires are relatively quiet considering the aggressive tread pattern and I had them Road Force Balanced. I can’t feel anything unusual in the steering wheel but I can feel it coming up through the seat and in particular in the center arm rest. I am guessing that the frequency is below the range of normal human hearing. In fact, I am not even sure that it is tire related. It is possible that it has always been there. The vibration isn’t strong enough to be noticed by most passengers but the old champagne glass trick confirmed that it is not my imagination and that it is fairly constant at all highway speeds. Any ideas on how to isolate the vibration would be appreciated.