Shake in front end

Okay, so I am a mechanic, these things do not usually stump me, but I cannot figure out my problem. I bought new tires last year and have had no problems with them until now. I was going about sixty five down the interstate this week and the steering wheel started to shake very badly, and it seemed to come from the right side. So I thought is was either hub, or a belt in one of the tires. When I got home, I jacked up the front and checked the hub on both sides. Both checked out. Next I moved the wheel back and forth to check the tie rod ends and it all seemed to check out. So I figured it was the tire. So I put my spare on instead and took it back down the interstate, and same thing. Any ideas?