1973 w200 steering?????

I hit a serious pothole this past winter and it felt like something had changed in the steering!!! Now every once in a while I get a SERIOUS left turn, right turn wobble when the truck is cold. [In the past I've just turned off the engine and restarted it and it went back to semi-normal] Yesterday it happened again, so I pulled over and I cycled the wheel left and right while sitting still. I herd and felt a small thud in the front somewhere and then I took off again and it seemed to be back to semi-normal. I asked my mechanic to check it out and he sez everythings ok and he even put a new inspection sticker on it for me. Its a mopar "708" steering box. This is not the dreaded death wobble as some have suggested but when it happens it definately is uncontrollable and I cannot procede.
Author: Coldrold52