[Motor31]

Welcome to out of warranty out of concern. :?

Before replacing check to see if the slide has dropped. When it goes in does the edges of the slide have equal clearance all around the opening or has it dropped a bit? If it dropped it would have a larger gap on top than the lower edges.

If it didn't drop your only solution is to buy seal material and replace it or have it replaced. Measure the seal you have now and compare to new material in a supply store and see if it did "shrink". You'll also need an idea of what size seal to buy anyhow.