[TowerTalk] crankup use and winter maintenance

[K7LXC@aol.com]

>  I am a relatively new crank-up owner (1 year) and have been  following the 
thread on crank-ups.  Jim's post on "crank-up use and  winter maintenance" 
begs the questions of:
a. What do you  lubricate the sliding surfaces with?
b.  What should be  used to lubricate the cable.
 
Howdy, TowerTalkians --
 
    Here's the lowdown on crank-ups and maintenance. 
 
    Several people have mentioned using PreLube 6 on  the cables - that is 
correct. DO NOT use a grease or anything else that'll coat  the cables. If you 
do that, the moisture can't escape and it'll rust from the  inside out. PreLube 
6 soaks into the strands lubricating them and doesn't leave  any residue on 
the outside of the cables that'll attract any crud or pollutants  that'll stick 
to the cables. BTW _www.championradio.com_ (http://www.championradio.com)  
has the PreLube 6.  It's what is specified by wire rope (cable) manufacturers. 
 
    The PreLube is pretty thin and will wash out  after awhile so an annual 
or semi-annual application will be real helpful. Start  at the top of the tower 
and work your way down. It's pretty messy so you don't  want to be climbing 
up and down the tower doing this. 
 
    Don't worry about the pulleys. Modern ones (i.e. US  Towers) have sealed 
bearings so you don't have to do anything with them. It's  difficult 
(impossible?) to lube older pulleys that don't have sealed  bearings so either way 
there's not much you can do. 
 
    The bearings can freeze up so a good thing to do is  to paint a mark on 
each one of them that you can see from the ground and then  watch them when the 
tower is moving to make sure that they're turning. Obviously  one that isn't 
turning is a problem. 
 
    As far as the motor drive mechanism, use a little  grease gun on all the 
grease nipples (zerk fittings) including the thrust  bearing and keep 
squirting it in until new grease starts coming out. 
 
    There are a couple of things you can do to prolong  your cable life 
besides lubing it properly. One is to exercise it occasionally;  that is, run it up 
and down a couple of times a month to, literally, work the  kinks out. The 
other thing is to not always park it in the same spot when  extended or lowered, 
usually where the limit switches are. If you do that,  there's a good chance 
the cables can take a set over time where they go  over the pulleys. Leaving 
it parked at different heights just about eliminates  this potentially fatal 
problem. ("Taking a set" means that the cable will be  permanently deformed at a 
point where it goes over a pulley.)
 
    As far as lubricating the sliding surfaces, I  wouldn't worry about it. 
The factory used to use a real sticky grease when  assembling the tower, now 
they just use paraffin. This makes it easier to slide  the sections during 
assembly but there's no easy or safe way to do it when it's  standing vertically in 
use. What material are you going to use and how will you  apply it? You'd 
have to do it when the tower is extended and that's definitely  NOT recommended 
since you'd have to have your fingers in there to do it. A spray  material 
won't last very long so trying to lube the legs isn't worth it IMO. 
 
    Crank-ups require more care and attention but doing  all of the above 
will prolong the service life of the tower.
 
Cheers,
Steve    K7LXC
TOWER TECH -
Professional tower services for commercial and amateur
Cell: 206-890-4188