The strangest body noise and vibrations

[troylatif]

Hi all, after recently getting my 85 380se to idle properly, I've been confronted with a new noise coming from the front right wheel well and general vibrations at higher speeds.

the vibrations first: I can drive the car around town up to about 40 mph. I can accelerate all the way up to about 75 mph on smooth road with generally no trouble. However, the minute I hit a rough spot in the road or I have to tap the brakes, I typically get a strong vibration through the steering wheel. I've already suspected unbalanced tires. I've taken them to the discount tire where I purchased them originally and had them rotated and balanced. I suspected shoddy balancing and took them back and they rebalanced them.

After the second go with balancing, I still get vibrations starting at ~45 mph and they can last up to about 65 mph. Vibrations can also now start anywhere above 45 up to about 65 mph. Could it still be a balancing issue? What could explain the fact that the use of brakes generally starts uncontrollable vibrations?

I read on another post created recently a response that listed out a number of possibilities having to do general vibrations. I get a strong feeling (quite literally), that the source of my vibrations are coming from the wheels but I can't quite figure out how. I distinctly remember the day they all started; I was driving out of my parking lot and I hit a huge deformation in the road doing about 45 mph. Since then I've had the brake pads changed and I don't recall the rotors being anything but smooth.

The body noise: Sometimes when I'm pulling out of my parking spot in the morning, I'll reverse and apply the brakes to stop and put it in drive. At the point when I put on the brakes I generally either stomp on them or ease on them.

In the case of easing on the brakes in reverse, I don't get any noise.

In the case of stomping on the brakes to stop the car in reverse, I often get a loud thud noise from the front right (I think) wheel well. What could that be? I had the front suspension completely rebuilt about a year ago which makes me think that something might be loose; perhaps a guide rod linkage, or an upper sway bar bolt, or an upper control arm bolt? The thought's also crossed my mind that maybe its a worn wheel bearing slopping back and forth, but that'd be a bit extreme wouldn't it?

At any rate, I appreciate your advice in advance,

-Troy