[mulligan]

I would give the track a good cleaning first. Then, considering that the roller system deals with 3 different materials (nylon roller, steel bearing, aluminum track), I would get a can of dry spray silicone and spray the roller area under the doors. Open and close the door to spread the lube, and give it a second shot. Let it sit for a few minutes, and give the track another wipe. Doors like new.