i've been getting some clanking up front at lower speeds. and im pretty suer thist is the problem. could it have been cause by overuse of the difflock?

 

i don't really think you can "over use" the diff lock, unless you are in it everyday. As time goes on you prolly will notice a lil bit of looseness, How bad does the u-joint look? I have heared that not enough use of diff lock will lead to some probs. but don't know how likley that is.