my 85 300TDT. HAve a vibration from right under the drivers feet. Feels like its dragging the car, thought it was wheel bearings, replaced them again and same. Thought it was power steering cause I just replaced the steering gear, so I cut the power steering belt to take it out of service, no change. Cut the A/C belt figuring maybe the unused compressor clutch was somehow causing the vibration or noise... nada.

It's bad, loud, goes away if if I turn the wheels slightly while driving, it dependent on engine speed, and If I shut engine down doing 80 it will go away (hence thinking maybe the PS or A/c)

The car feel under powered

The brakes and rotors are brand new bosch quietcasts. I've replaced the inner and out wheel bearing and chases on both fronts and the drivers side now twice.

It's driving me nuts and I'm having to park the car till I figure it out.