I have a 2000 itr tranny, the passanger side tire shakes at around 65-75mph, i inspected my brakes, alignment, hub bearings and they checked ok. I picked up the front of the car and placed it on jack stands and i strap the rear end to ancher for safety. i noticed my passanger side axle as it rotates moves up and down like not center, so i went to buy a new axle and problem still there.

any suggestions?

 

Its probably your diff bearing that needs replacing. We can do that for you. PM me.

 

It is very possible you have a flat or high spot in the tread of the tire. Put each tire up in the air, and spin it to see if you got a flat or a high spot. Bent rim will do that as well.

If you feel it in the steering, its probably in the front, if you feel it in the seat, its probably in the back.