Violent shake on light acceleration
 

Let me provide a brief bit of info about the truck first, then describe the issue I'm having. I have a 95 C/K 2500 extended cab 2wd. It is bone stock, except for the tires which are GoodYear M/T R's. Last year I had the midship bearring replaced because it was making a loud pounding noise. Ever since then, I get a violent shake when I modulate the throttle to either keep my speed even, or on slight acceleration. It seems to only do this in 3rd gear, because once I throttle hard enough to drop down to 2nd, it does not shutter. Does anyone have a clue what this could be?
I though at first it might be the Ujoints, but it is throttle controlled, not speed, or RPM related. Any help would be greatly appreciated.

I still would say something with the drive shaft still. Either the u joints or carrier bearing. The only for sure way to check u joints is to take them apart. I had to. As soon as I did they fell apart.

It sounds like to me the converter is locking and unlocking for some unknown reason. I would try to isolate when exactly it does it and when it doesn't.

Well, it happens when in 3rd gear, and I try to accelerate lightly. If I accelerate enough to drop down a gear, it only sudders until it drops down, then hauls ass.

bumps