I have an 05 Equinox AWD automatic. It has a vibration throughout the car when I am driving between 35 and 50mph. If I let off the gas, or apply the brakes, the vibration stops. It only vibrates when I'm on the gas between 35 and 50. A friend said it might be the steering column. Does that sound reasonable? If so, does the whole steering column have to be replaced? (It also makes clanking sound over bumps, but I think that is because I need to replace the front brake caliper bushings)