i basically took a wire wheel hooked it up to a dremel and just got all the surface rust off of my new trucks frame as i could then get the bedliner in a can and sprayed the whole thing and it works great

 

Everyone here has been so helpful...thanks so much! I am going to post some pics on another thread of the underside of my truck. I'd really appreciate it if you could give some feedback whether or not I should pursue fixing it. When I look at the frame, it looks like surface rust. When I look at the axles and other things (the names of which I don't know!) I am not so sure. Having an accident while pulling my horses really scares me.