I would oil them if there isn't a chance it might seep in some where it can do damage like inners of the motor. If the manual doesn't particularly call for grease I guess there's no reason to go for it. Grease last longer, but it doesn't lubricate better, oil usually makes a machine turn lighter and less to clean up when reapplying.
For a comparison I have experimented with my 201s, they have three sets of cork screw meshing gears. I have the belt driven motor on mine (the 201K-2 is few and far between here). I have tried the best of greases, but it runs a notch or two lighter with oil, and oil coats the gears and the basic oiling routine with the rest of the machine is enough. I find it easier too, and I like teflon oils like Finish Line ceramic wet lube and Triflow. A good basic oil is fine too. If you have a nice light running grease it shouldn't matter much either way, but so far I lean towards oil when it's an option.
Last edited by Mickey2; 12-01-2017 at 02:24 PM.