When I start down the road my truck shakes like the wheels is coming off then after driving about 20 minutes it stops. Feels like the rear end is coming out or the wheel is coming off.

If you live in a cold climate, switch to 5W-30 synthetic engine oil. I would also drop and clean the transmission pan and magnet, change the filter, and refill with Valvoline Synthetic ATF+4 transmission fluid. Similarly, I would drain and refill the differential with Mobil 1 Synthetic 75W-90 Gear Lube LS.