many [most?] ball bearings now have plastic cages, shouldn't cause a problem, but that's likely the cheapest Chinese production, look for a better one at a local store - NAPA has a replacement guarantee, they gave me a complete new clutch kit when my throwout started making weird noises at 11 months .... the manual is talking about the 50 year old style that wasn't a sealed bearing, only takes a very light wipe of grease on the contact surface of todays style
Bill
