The aluminum end caps on my slide toppers had badly worn the axle hole into an oblong shape. Moving the slides in or out was accompanied with a clunking sound. Don't know how long it would be before some type of catastrophic event so I decided to replace them. I could not find the end caps for sale online except as part of the complete spring assembly. They cost $95 each, I had four needing replacement. Cost for parts would be in excess of $400 with tax and shipping. I decided to repair mine instead, total cost for all four=$12.
I made an external steel bushing using thick washers and attached them with drill screws. I spent more time making the bushings than I did installing them.
See you down the road!
Larry
2000 Winnebago Adventurer
20,000lb F-53 w/ 310hp Triton V-10
towing: 2005 Dodge Ram 1500
towing gear, Blue Ox
Our blog: Dispatch from the Road