2001 lincoln nav having problem with either vibration or vouncing of right side tire on passenger side when i exceed 60miles per hour. I had the pitman arm and the idler arm replaced and it still doing it once in a while...any advise?

Does the engine run smooth even when this happens or is there a vibration along with the noise. Are you familiar with the symptoms of a misfire, and if so, how does this compare with a misfire?

for your own safty and that of those who ride it, get it to some repair facility that has a lift-because it is only a 2008, it might be under warranty, and it might be as simple as a badly balanced tire (threw a weight?). A frozen or hanging caliper, bad wheel bearing, or a tire that is badly under inflated might also be the cause-just get it checked out.

The 2001 Lincoln Ls v8 has three fuse boxes Located: 1. Under the Hood on the passenger side, 2. Under the dash on the passenger side behind a kick panel, and 3. In the trunk next to the battery where your spare tire is.
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Which tire front or rear? also when you say right do you mean passenger side or driver side? If you wish to say I will reply back to you as it will be different depending which tire it is and if it's passenger side or driver side.

If you can absolutely verify that there are no loose components in the front end I would start looking at the tire for belt separation. This can be detected by rubbing your hand gently over the tread area. Feel for bumps,bulges, and irregularities. It should be fairly obvious.

You can also try putting the tire on a different location and see if the symptom moves to the new location.

the next thing is to have the tire checked for a hop in it,meaning its not straight and round, start there.

If you getting a lean code you may want to start by changing the fuel filter. I'm not that familiar with the Navigator but, If you look at the coil pack they have them numbered. The right front (passenger side) cylinder is number "1" it's 1 2 3 down right side and 4 5 6 on the drivers side, that's for a V-6. A V-8 is the same except 1 2 3 4 and 5 6 7 8.

Let me see know at 45 miles per hour a vehicle usually shifts gears into the highest gear so could it be the torque converter hanging up and not shifting quick enough or maybe its the U joints. Have the transmission fluid checked for proper level and color.
Here's a small test for you when your accelerating up to 55 miles per hour try letting off the pedal at 44 miles per hour and then reaccelerating up to the 55 mph and tell me if it`s smoother if it is then chances are that it`s hang up on third gear. There's also a electric sensor located on transmission that assist shifting it`s usually controlled by the engine timing.
One more thing did the repair man check to see if the tires where directional tires if there not put on right it could cause vibration and early wear out .Hope i helped you.

This is very common. It can either be your tires need to be balanced. Or your car needs to be aligned at an alignment center. One or the other should stop the vibration.

The tire it self may have gone bad. Try rotating the tires from the front to the back and see if there is any difference and start changing the tire pressure. Start by going with the recommended tire pressure for the car. There should be sticker on the drivers door and work your way up or down and do not exceed the maximum tire pressure on the side of the tire. The other problem is one of your tires may have a tire belt separation, causing the tire to deform during high speed. Good luck and hope this helps.