Glide block replacement?
 

Has anyone replaced the glide blocks that ride the vertical guide rails on the bottom half?

I think you can use the same instructions for raising the roof for replacing the roof gasket. It is then raised high enough to replace both the gasket and glide block. That info is posted in this forum.

Question: What is the problem with the glide block? Why does it have to be repalced?

I replaced some of mine several years ago, I stopped at the factory repair place, which is now J&R Repair. The fellow there told me to remove the guide rails on the side opposite the broken ones also remove the guide rails where the blocks were broken, you do this with the top up. Then lower the top and push a piece of wood between the top and bottom of the trailer, this swings the top over just enough to use a 90 degree driver to remove the 4 screws. He said it isn't easy to do but he assured me it can be done as that is how they do it. It wasn't easy but I got them replaced.

The gasket was replaced a couple of years ago, the glide blocks are just plain worn out, they are not grabbing the guide rails. It's a 17 year old trailer.

Did it and it worked like a dream. Thank you!