1993 Oldsmobile Cutlass Lateral shuddering while driving

Hi Guys!

I've had this problem for several years now where my car shudders and makes a dull sound while driving, especially when in a sweeping turn, as on the highway. It varies with steering angle where in the steering dead spot I typically hear/feel nothing wrong, but when I make a left or right turn I get a periodic "thumpthumpthumpthump" sound and vibration.

I also get a pronounced shudder as I brake. I thought this was just warped rotors but I've had them ground a few times to no avail.

A friend said it may be a funky CV joint, and my talents lie in electronics, not mechanical systems so I haven't the slightest idea. =P

My car runs swell, though lacking power currently and I want to see it reach 250k miles. What should I do to correct this problem? I'm donating to the website for this answer.

Thanks!