Weird acceleration vibrations from drivetrain

Truck is still shaking from 30-40 mph after torqueing the bolts down again, specifically the rear end is shaking, when I get a chance I am gonna balance the two rear wheels and already ordered the spacer.

 

Driveline shudder is how I found this site. I tested to see if it was my problem by loosening both bolts, completely removed the other and added about 3/4" worth of heavy duty washers as a makeshift spacer. It worked, so I ordered the real deal.

 

So I started to hear a clicking noise coming from the rear of my truck, makes me think I've been experiencing symptoms of a bad axle bearing, anyone know what parts I will need for this job?

 

I think I've got a bad axle bearing along with some vibration from the driveline never really noticed the clicking noise until yesterday when I hauling some stuff in my bed