Dig, welcome to the Newmar forum and irv2.
If you go to
QT # 1 & 2 and scroll down to the slideout information section you will find the info needed to fix your problem in the Trouble section of the old slide spec link.
Before you do anything go outside and look under the slide and see if you have any broken stop rods or brackets attached to the rod stops on slide outside edge or the one under the frame of coach that rod guides through.
You may need to only release the torque bushings and with help push the slide in and re-tighten the bushings.
You will find more info for your coach in all the Quick Tips links at the top of this forum, let us know how you make out with the problem.