2003 Toyota Tundra sr5 review from North America

The frame shake began at about 20K miles. I attributed it to the "factory" tires beginning to wear out and wear unevenly. At 40K miles, I put on a set of Michelin M/S LTX and the ride got worse. I started calling. I had the tires rebalanced with no improvement. I took the truck to an alignment shop, he told me it wasn't an alignment problem. I took it to a Toyota dealer in Statesville, NC. They told me it was characteristic of the Tundra ride and everything was fine. I took it to a Toyota dealer in Concord, NC and although they told me it was characteristic of the Tundra ride, they at least tried to lessen the shaking by lowering the air pressure in the tires. I called the Toyota company customer service line, was set-up to meet the area representative, Jim P..e, who went for a ride in my truck and was again told it was very normal. Does anyone else with a 2003 SR5 Tundra have a ride so severe they can make a milkshake on the front seat? Is this normal, or characteristic? I think its the pits and it didn't start out this way. It wouldn't be so bad if they would just fix it. I would pay to fix it. They tell me its normal and can't be fixed. Personally, I've had 3 other Toyotas in the past. This one is really bad. I guess I'll go back to Ford. It's no better, but it's easier to pay for.