Heres a link to the manual from the original ESE hudson back in 05. "Assuming" the tooling is the same, page 27 may shed some light on the coupler, and page 28 highlights lubrication areas:
https://www.lionelsupport.com/...ents/73-8000-250.pdf
I add .5 to 1.0 ml of red n tacky grease to every new loco I get before I run it. It should then be good until the next person that gets my locomotive.
Many times grease is lacking from the factory or is stuck to the side of the gearbox instead of on the gears. Diesels are the biggest offenders when it comes to a lack of grease from the factory, but I won't take chances on a $1000+ steamer.