I've put about 5,000 miles on it since I put it on the road in late December 2016. Didn't really notice a vibration problem when I first started driving it, but seems to be progressing. I had all of the wheels rebalanced, front rotors turned down and replaced the steering shaft, (definitely worn). There is no vibration through the steering wheel as in the front end. I'm pretty sure it's coming from the back end. When I pull up the e-brake I can feel the vibration really pick up. I also noticed that when coming to a slow stop the rear brakes squeal a bit. Upon inspection, I can see where the brake shoe(s) are rubbing on the backing plate, thus squealing. I replaced the drums with not much improvement. With the new left drum as well as the old one it replaced, when I free-spin it, something appears to be out of round or off center because it does not continually spin free. It slows down as it seems to rub the brake shoe at a high spot. I also checked, (best I could), the rear wheel bearing and couldn't find any free play.
Also to add is that the vibration is not as intense all the time. There always seems to be a [minimal] vibration, but at times it gets worse. It fades in then out.
Thanks for the help.
added 2/27/17 Had some time this past Saturday to inspect the problem. Removed drums and sprayed brake cleaner. Appears that the brakes and hardware were replaced not that long ago. Shoes were rubbing back plate. Removed shoes and hardware and replaced using lithium grease where needed. I again spun the left wheel bearing and could not see anything wrong. I clamped a screwdriver so that the tip would be right at the axle/bearing flange spun it again. Definitely bent. Put it back together and ordered new wheel rear bearings. Drives now with less vibration but still there. We'll see what happens with the new bearings.
[This message has been edited by FieroTony (edited 02-27-2017).]