I have a weird shimmy in my 1950 3600 tow truck that I'm not entirely convinced is coming from the steering. I feel it more through the seat of my pants than through the steering wheel. I suspect the tires are out of round or something. It was up in the air this weekend while I was rebuilding the steering system, so I looked carefully at the wheels and tires. I couldn't see anything obviously wrong with the tires, which are 255/70/16 radials on standard dually deep dish wheels. But one of the rear wheels (passenger side, inner wheel) looks different than the others. The edge of the wheel was far less defined than the other wheels--there was less of a "step" from the wheel rim to the edge of the bead, and the outer lip is much more pronounced. Check out the photos--the first two are of the wheel in question, while the third photo shows what appears to be a normal 16-inch wheel mounted on the other side of the axle.
I did some looking and found a few photos and discussions about 16-inch tires on 16.5 inch wheels. Most of the discussion is about "don't do it!" and the accidents that people have heard/seen, but there weren't many posts saying it couldn't physically be done. I would think that it would be impossible to stretch a 16-inch tire an extra 1/2 inch (which, in terms of circumference, is more than 1.5 inches of stretching a steel-reinforced tire bead) but I think that's what's going on with my tire/wheel here. I think the moron who owned this truck was so cheap and such a hack that he figured out how to do it and risked life and limb to save a few pennies. What do you think? I don't know what a 16.5-inch wheel should look like.
