I have a 2008 Cyclone 3010 Travel Trailer with one slide. When closed, the roof contacts first which I believe to be normal. The slide seals along the top while closing very well. Then the bottom pulls in several inches after the top makes contact. However, the front of the slide on the outside seals great, but the bottom rear has a decent gap. How do I adjust to pull that corner in? I purchased used, so don't own a owner's manual or know a thing about the electric slide mechanism.