1997 mountaineer making thumping noise at wheel/tire when going uphill or just pulling off

What is your question?

mountaineer making thumping (like metal on metal) sound anytime it has to "pull" such as when at a stop sign and taking off. does it VERY bad when going up a hill, but no noise when regular driving on flat ground. mostly just when pulling a hill. it sounds close to front left tire. guy said it may be universal joint or gear box??

What makes this problem better or worse?

going up hill, or taking off from stoped position

How long has your 1997 Mercury Mountaineer had this problem?

few weeks, getting worse