Can you replace the bearing in an idler pulley?

I suppose you could, but these idler pulley's are not that expensive to replace the whole thing. They do fail (a weakpoint for these motors), but usually give some audible warning, also check for loosness. Do your best to purchase the steel idler pulley and the bearing will come with. When these items do "let go" they can leave you stranded, if you see a problem replace as soon as possible. Hope this helps. "G"