Very bad vibration on my truck?
I have a 2000 ford ranger 4x4 with a 3 inch body lift and 4:11 gear ratio swapped for my big tires… Which are 33x12.50 mud claws. Anyways, at low speeds, it is kind of an annoying vibration around my feet area. When I get over 45mph, it gets scary as hell. The vibration turns to a shaking of the entire truck. Now, it still handles perfect, and I checked the U joints and they were fine. I checked front and rear diff fluid and it was fine. I didn't see any leaks. I checked wheel bearings and they were good. I checked the CV axles for any torn boots or play and they seemed fine. I even jacked it up and spun the tires in drive with it running, and no noise. I'm lost… Maybe it's just the tires? They are very aggressive mud treads. Maybe they aren't balanced or I slung the weights off or something. I don't know. The only thing I noticed is a little more play in the rearend than I would like. I can turn the driveline a quarter turn in both directions in nuetral and wheels on the ground. Any ideas, advise, things to check next, or anything would be appreciated.