Idk why and for the life of me cant figure out whats the cause but I have a terrible vibaration in the peddle and on the floor that your can hear between 75 mph and 85. Before and after these speeds theres no hint of anything. I dont get it. Any ideas?

 

tire balance?

 

u-joint maybe.

 

tires are balanced and U joints have been replaced recently.

 

Probably unit bearings or hubs then.

Mine developed a similar vibration to what you describe at about 75 mph too, but it started when I put the Toyo's on. I think they start to act up at high speeds. I know a guy who has the same Toyo's on his Jeep, and he told me his do the exact same thing at the same speed.

 

Your drive shaft could be out of balance even though the U-Joints were replaced. There could be debris (mud, dirt) on a tire causing it to be out of balance. Ball joints worn? Tie-rods?

 

So i should have my drive shafts balance checked. Ball joints have also been replaced(many times) recently. Not sure what Tie-rods are or unit bearings?

 

Tie rods are what connects your wheel assembly to your steering. There are multiple pieces to the tie rods and if one of the pivots is wearing out, it will be much more noticable at higher speeds.

To check your tie rods, climb under your truck and grab ahold of one of them and give it a shake. If it has play, then its time to replace it.

I think what he's calling unit bearings are what I call wheel bearings. Your front axles are held in by wheel bearings. They can be kind of a PITA to get out, but if they are shot, you have to replace them.

I think the way to check your wheel bearings is to jack that tire up off the ground and try to shake it a little. If you get some play, then your wheel bearings are probably shot or on their way out.

 

Shake it in what way?

 

Jack up the truck, grab your tire at 9 o'clock and 3 o'clock, and see if there is play back and forth as you push and pull on each side.