Ok first I have a 1996 1/2 ton 2 wheel drive about 8 mo ago all of a sudden I got a vibration took and had tires rebalanced still there replaced all u joints and career bearing still have it then replaced rear wheel bearings put back together still there replaced all bearings in rear end still there went had tires checked for run out all tested good. the vibration is bad enough to shake the lug nuts off I have lost 4 lug nuts and then one day my wife was driving all lug nuts on drivers rear was gone but the lock pulling my hair out jacked up checked every thing I can any suggestions has about 180,000

 

Maybe the gears in the differential are damaged? I'd jack both rear wheels off the ground and put the rear and on jackstands so that the rear wheels don't touch. Then have someone set in the truck and spin the rear wheels up and see if you can find out where the vibration is coming from

 

I did that also could not find any thing that is why I pulled rear end apart and changed all bearings and looked over the gears real well could not see any thing only thing I can think of is have drive line balanced but have not justified 180.00 just to have it checked out yet then to find out that was not it thanks NullHead That's what I am looking for is other theories

 

Possible the drive shaft is out of balance? It has been known to see drive shafts take a hit to knock them out of balance or simply they can through a balancing weight to send it out of balance.