Hi looking for some advice ? ive just brought a dlx2040spe , I think the drill in the pair is a dhp481z , any way at slow speed the drill makes a crunching noise until you pull the trigger in a bit then it stops , I spoke to the guy I got it off and he said it has hammer in every mode? if that's the case why would they put a hammer mode on the drill if its on all the time?? if I put the trigger in half way it runs smooth but if I wanted to slow right down (say putting a screw in ) at low speed it makes a hell of a noise , any help would be great thanks