[TowerTalk] Stuck thrust bearing? Help needed.

[W7ZZ]

Today, I tried to rotate my antennas in a clockwise direction.  My Green
Heron control box for the Prosistel 61D gave me a “no rotation” error
message.  I verified by looking out the window that the antennas were not,
in fact, rotating.  I then tried to rotate counterclockwise and the antennas
did turn, although it seemed that they turned more slowly than usual, but
that’s hard to tell for a small amount of rotation.  I went back and forth
like this several times until the antennas had been rotated counterclockwise
about 90 degrees.  They still would not rotate clockwise, and finally they
wouldn’t rotate counterclockwise either.  I applied the “truth table” to the
rotator and it seems to check out OK.  The Green Heron checks out OK.  I’m
thinking I have a stuck thrust bearing.  I use two pillow type thrust
bearings supplied by the tower manufacturer (AN Wireless) and the tower has
been in the air for about 3 ½ years now.  I lubed the bearings before
putting the tower up and once since then, probably about a year later.

 

Any other guesses as to what’s wrong?

 

If my guess is correct, any suggestions on what to do, since removing the
bearings would require me to remove a 2 element 40 meter beam, a 4 element
Steppir and the mast, not an easy task at the top of a 70 foot tower.

 

Suggestions appreciated.

 

73 Doug W7ZZ