Vibration
 

Can bad wheel bearings or someting inside the diff case cause vibrations while driving at high speeds, lets say 40+ miles

Re: Vibration
 

yes. any worno out bearing will allow play on any shaft and cause minor vibration worsening over time till it is violent.

Re: Vibration
 

almost sounds like a driveshaft that's out of balance

Re: Vibration
 

The driveshaft still has the weights on. could engine timing cause any of this, cause it was way out, advanced

Il still change bearings on the rear axle

Re: Vibration
 

I was thinking wheel bearings or maybe bad u-joints?

Re: Vibration
 

tires/rims?

Re: Vibration
 

How can the tires cause it?

Re: Vibration
 

tires right off the assembly line are not perfectly balanced and neither are your average rims. so we apply lead wieghts wether it be clip or stick on to even out the centrifigul force. you will notice tires being out of balance as the wear and the vehicle always feels smoother when you get your tires rotated and such..

another culprit could be water in your tires from a bad seperator in your aircompressor. mud inside your rims.

or even flat spots from the tires not being fully aired and sitting for too long between drives.

driveshaft could be the culprit being bent but i dont think that is your issue.