MT 2015 conversion today for the first time. I did not understand the concept of lubing the spine however now I get it. I was unaware the spine moved in and out of the universal housing. That’s why the spring is there. Duh. The spine was dry as a bone. Not any longer. Also lubed the universals of course. It was a learning experience for sure. The project was pretty straight forward. Just took time. I did tie the fore and aft u joints together with a rope prior to starting. Worked like a champ. Just an FYI for those interested.