Z trapezoidal leadscrew
Magnalube can be used for lubricating the Z trapezoidal leadscrew. Spread about ten drops of grease over the entire lead screw. Raise and lower the build plate through the menu again to equally distribute the grease.
Do this approximately once every six months.
Caution: Do not put Magnalube on any of the other axles as this will affect the working of your Ultimaker 3.