Still not sure if it was a good idea or not but on my square shaft, I capped the inner tube and tapped a zerk next to the ujoint. I drilled multiple small (1\8") holes along the 4 sides of the inner tube. The inner tube gets filled with grease and greases the slip evenly. It works great although it does add extra weight and probably vibration to the shaft but I will never be using it on the road. Just thought I'd throw that out there!
