Several Questions about Issues with Slide out, (pics incl)

rjxj wrote:
Maybe water got in there and you are feeling spongy wood. Lets hope not.

I agree. I would remove inner membrane molding and pull back that membrane and see if any water damage exists on the roof sheathing, and then go from there. Until then, leave your slide closed to prevent further damage.
I recommend going to the Jayco owners forum (Google) and ask what slide mechanism you have there.