Where does one start to regain the smooth ride his truck once had. Toyota Tundra
The first thing to check are the shock absorbers.
Shock absorbers can fail in the internal valving. When this happens, the shock can no longer compress to absorb bumps. This results in a very stiff/harsh ride.
Go to each corner of the vehicle, and push down and release it in a manner that allows the suspension to begin to ocillate up and down. If there’s anything wrong with any of the shocks, you won’t be able to get that corner occilate down and back up.