Major Vibration while driving????

[Geno Cochino]

Hey guys, Just got new tires on my 03 FX45....
Been enjoying it for a couple of weeks now and just yesterday noticed a pretty heavy feeling vibration while backing up.... Then this morning I noticed it was way worse and was pretty serious while in Drive. I feel like its got to be a drive shaft issue or something along those lines, almost feels like a motor mount, praying its not a rear end or trans problem...
I took it to a mechanic and he wanted to service the rear end, was going to start there but now I know its not that and much worse...
Any ideas?

 

[la_fx35]

I had a straight vibration a little while back. It'smost appearent when accelerate from stop. It turns out the u-joint on the front propeller shaft was broken.
How to Replace Front Propeller Drive Shaft

 

[neva4self]

Who balanced your tires? There's a chance they didn't balance them well.