I have a 99 f150, 4.6L, 4x4. My suspension is acting weird. sometimes the truck rides just fine and other times it acts like the shocks are shot. i replace the shocks not too long ago and it started acting up about 2-3 weeks after the install. its like it has a mind of its own. also, the rear makes a like squeaking like sound too. i think it may be the bushings in the leaf springs but i am not sure. would this have something to do with the inconsistancy of the suspension?

Also, ive noticed that the wear on my front tires in not normal. on the outsides of the tires the wear is not smooth. almost like a cupping wear. it makes a roaring sound when braking and turning. i think i may have a bearing going bad. could this be the problem with the uneven wear or it is something else.. any help will be greatly appreciated...

 

Have you checked the ball joints and tie rod ends? Are the sway bar end links broken or still intact?
Cupped tires, due to bad wheel alignment or worn parts, can make a roaring sound.