Lots of things to do here,
Give us a better description of the type of vibration, and when it occurs. Gear, speed, coasting, braking, neutral????
Your front driveshaft should spin 360 degrees when in 2WD with hubs unlocked, I'm pretty sure...
Check your engine to chassis ground. Try using a jumper cable connected to negative battery terminal on one end, the other to a good unpainted part of the engine. If latter works, it’s likely a ground issue.