Can you see across the top of the slide box, could their be something laying their stopping the movement (are you missing the cat)
You might try posting this on the Monaco owners forum. Also their is a slide seal cleaner and conditioner to keep the seals flexible, then check for rollers under the slide, might need some silicone spray on them. I also used some Mothers Carnuba wax on my slide box. that helped it slide easier, no squeeks. I took a cheep sponge floor mop and spread the wax on the outside wall of the slide, did not buff it, just left it thick.
2004 National See Breeze LX8375, Towing a 2012 Liberty
retired. Now What?