[TowerTalk] Sluggish crank-up tower

[Rick Stealey]

K2XT, Rick here.  I've recently been having trouble getting my tower to extend easily.  It is a US Tower TX472 with the motor drive.  Symptom when I first experienced the problem last fall was very sluggish starting.  I'd give it a few seconds in each direction and then it would get going.

So now that I am in the midst of extensive maintenance (new winch cables, and some antenna work) I notice that the motor stalls out completely, and blows it's circuit breaker or thermal cutout, whatever it is, after 2-3 seconds. And of course there is no upward movement of the sections.  I replaced the starter capacitor.  Same thing.  I removed the motor and it runs fine with no load.

Ok, so my next theory is a pulley is jammed, and that's where I seek some advice.  I tried turning the "steering wheel" pulley by hand while the motor is off.  That is the approximately 8 inch pulley that is driven by the belt from the motor.  In the direction that should raise the tower sections it gets so tight that there is no way whatsoever a human could turn it more, and my gut feeling tells me there is also no way I should expect the motor to turn it.  So, do I have a bad pulley on the tower sections,  and how to know if a pulley is bad?

So, this morning, with the tower horizontal, I loosened the winch cable and removed a bottom pulley.  A 3.5 inch dia one.  I can hold the bushing and try to spin it.  It turns and I can feel the bearings inside but trying to get it to spin and it only goes maybe a quarter turn.  The feel of the bearings is sort of uneven.  Could that bit of friction be causing the trouble?  Of course I may find another pulley (hopefully) that is completely frozen, and that would solve my problems.  Any opinions?  Any first hand experience with such a situation?  I put some motor oil on the bearings, no change.  What about soaking the pulley in solvent, then oiling?

Thanks for any input.

Rick  K2XT