Ironically, the guy who came out told me that lubricating the rollers
at the bearings was one of the causes of them wearing out because it
causes dirt and grit to stick which grinds them down. Only lube the
shafts. I'd sprayed WD40 on them many times but didn't seem to make
any difference. I wondered if that was the proper lubricant and he
said use a silicon spray.

Brad