So... while taking out the driveshaft for new u joints I checked out the slack in my rear end (where the driveshaft bolts on). Way too much movement, I think its time for a new main bearing.

Could this bearing have caused other damages as well?

do you mean a U-Joint??

I think he means pinion bearing(s)....

If the flange is flopping around you could try tightening the pinion nut some. If it's moving a lot then it's probably too late to try to fix it.