Sounds more like a bad shock absorber somewhere. You go over a bump, and the suspension loses it. There might even be a resonating frequency that a good shock would normally dampen. Then you feel it through the entire driveline. I dunno, just an idea. Have someone drive next to you and see if you can get that to happen. Have him tell you if one of your wheels starts bouncing up and down real rapidly.
If that's not it, might want to give it a once over, make sure u-joints and driveshaft and everything is cool.
If that doesn't reveal anything either, Midas will troubleshoot it free of charge. They'll want a million bucks to fix it, but once you know what it is, you can go after it yourself probably.
Just a few ideas.
