Sailmaker,
If you have the tools and the know-how to do it yourself, you can save a bundle of money on replaing the ball joints. However, If you feel you are mechanically challenged or don't care to make those repairs, simply take your vehicle to other indiependent shops for some quotes. I'm sure you will find that the labor rates you pay at a Ford dealership are at least twice what you will pay at any other reputable repair shop in your area.
The best part of doing it yourself or having an independent shop replace the balljoints is that you will find that nearly all aftermarket balljoints are better and cheaper than anything Ford will replace them with.
If you brough you vehicle to the dealer at 33K miles complaining of shaking and they did not make any repairs, you should argue that point with the dealership. They may not do the balljoint repair for free, but they may give you a significant discount. You can also replace the tires and if you still have the shake it would indicate that their original diagnosis was wrong. Agressive tire treads do not cause shaking or vibration, but they usually make more road noise.
You should have challenged them when they told you that line of BS, but you didn't and that told them that they had a nieve truck owner. The service writer probably told you that when you arrived at the service department and never wrote up your complaint and so they never checked out. If they never wrote it down, you don't have any documentation to prove that you had the shaking problem at 33K miles and brought it in for that reason.
Just a rule of thumb to avoid your complaints from being brushed off...
Always insist that they write down your complaints as completely and accurately as possible. Even if the service writer gives you some half-baked excuse for that problem, Tell him to write it down, and if nothing is found to be wrong, still ask him to write down his half-baked excuse as the reason no action was taken, If they write it down on the service order, they cannot deny that you complained. If you accept their excuse and they never write your complaint on the service order, you have no documented evidence that you ever made the complaint.
...Rich