I’ve always been of the opinion that anything you can do on the ground, can be done on the tower. It’s mostly mind over matter. I think I enjoy the focus it requires. I’ll concede it takes longer - this was just over 4-hours - and having everything you need if you are packing can be a challenge. The bigger challenge in this work is rotating the blades without a gin pole. They pretty much have to go on one at a time in the (downward) vertical position. This means you need some means of a rotor lock, and I highly recommend one for maintenance work. In our case it is just a set of two coupler nuts that I thread on to the backside of the rotor. They stick out just enough to lock against the stator bracket, and with two, you can walk the thing up, or down, in stages.
These are the threaded ends (4 of them):
I think you can see one in use here; helpful when ultimately you need two rotated up at 60 degs off vertical, right:
Timken recommends between .001-.005 end play. Their procedure is to:
torque to 50’# while rotating,
loosen one full turn
continue spinning and torque to 10’#
back off 1/6 to ¼ turn
The spindle is fixed with respect to the tower, so from a horizontal position your just pulling down. It’s pretty simple.
I didn’t mess with any of this on this round. I found that two flats was tight to where there was noticeable pre-load and some restriction; one flat was “just right”. A lot of work for one flat, but if it keeps it quieter and prolongs the bearing life, I think it will be worth it.
