I'm going to oil bathe this shimano nexus 7.. the proffesional bike repair person I asked to do this for me sprayed wd40 in it, €80 later I decided to just buy
Shimano Nexus 7 Speed Hub
Redondo 26 Inch E-Bike Rear Wheel Rim Shimano Nexus 7 Rear Pedal Brake : Amazon.de: Sports & Outdoors
Review: Foffa Urban 7 Speed Nexus bike | road.cc
Shimano Nexus 7 speed hub Archives - O2feel e-bikes AU