I have an 03 Coleman Niagra with a middle slide out for the dinette. This thing seems to be sliding out very roughly. Do they normally roll or glide out? We put new peel and stick flooring down in the camper and now can visibly see the bottom edge of the slide-out on the inside is rubbing the floor as it is pushed in an out and it looks as if it has done this for some time. The edges on the inside portion are chipping as it is slid in and out. Before you wouldn't notice it because the floor was a yellowish-brown and so was the sawdust/wood shavings but now it is a dark floor we are able to see exactly where it is rubbing. I also have to "bump" the slide with my weight to get it to go all the way in.. I guess because towards the end it is contacting the floor as if it is leaning some. What should I be looking for to try to fix this? How much clearance is between the bottom of the slide-out and the floor inside usually?