If it's just discolored from being overheated, it's a judgement call. I've been using Moly for nearly a decade and never had a callback for a motor problem. Just oiling old bearings will not last. Factory lube gets like honey, then siezes up. That's why it's important to wash it out.
Some capstans have two different bearings, a roller type on the bottom and sleeve on top.
In my opinion, it should be the other way around since the top bearing takes most of the load with the pinch roller pressed against it. The sleeve bearings are the ones that need the new lube.