Has anyone used ball bearings as window guide rollers? Good or bad idea? I need to replace the window guide wheels for my 64 Riviera. They spin, but are tight. I soaked them in penetrant (Gibbs), and spun them on a electric motor, but they're still stiff. For the cost of the replacements, I can get high quality radio control ball bearings that are the exact size I need (17mm diameter, 5mm wide). Metal bearing housings riding in steel tracks might scrape some, but to me if it's greased it should be fine. Closest thing I've seen is nylon rollers (with internal bearings) for shower doors. But they're all too wide, and would need machining to fit. I bought one to test with, and the plastic roller part is too thin to cut down. Done it, or seen it done?