I have a 2002 Tundra with 40K miles. From day one there has been a steering wheel shimmy. Numerous re-balance, rotations, and new tires have not solved the issue, only helped to lessen it. I have not had the tires balanced while mounted on the truck.
I have spoken to other Tundra onwers in the same year range that had similiar problem.
Any thoughts on balancing or an after market steering dampener?
Sounds more like a steering issue that a tire. I would think that a 02 would have a rack and pinion, which might have a defective design. Especially since other owner have had the same problem. You should check with your local dealer and see if there is a recall on it.