hookset, do ya have the regular one or the hammer drill? I have the XRP hammer drill, that thing takes a beating. There are some plastic parts to it though. It can get heated up if you're doing a lot of drilling, or using a greenlee bit for electrical work.. Sometimes I stick mine in a freezer for a few minutes when I've been beating on it for awhile.

Normally I would say it might be your brushes, but it just your reverse is sticking, it could be the switch. You could take it apart carefully and clean it up a bit. If that's beyond you, there are a few Dewalt repair stores in NJ.Good luck.