Rick,
The pulley bearings do seize up at over time depending on WX and your
environment, especially if the tower is left in one position for a long
time.
Tashjian Towers did sell replacement pulleys at one time. US Towers may
too. You'll have to call.
Like you say, you may have more than one bad pulley, just check them all.
If the pulleys/bearings do not move smoothly, replace them. The real old
Tristao and Triex towers used Fafnir K8 bearings that could be pressed out
and replaced. These bearings are very hard to find now. Don't know what
bearings the tower companies now use.
73 & GL,
Ray,
N6VR
On Fri, Jun 20, 2014 at 10:03 AM, Joe Giacobello, K2XX <k2xx@swva.net>
wrote:
> Rick, I had a similar problem with an LM-470. It turned out that the
> solution was a rusted shaft between the motor and the large pulley. A
> squirt of oil onto the shaft and toward the portion of the shaft inside the
> motor did the trick. YMMV.
>
> 73, Joe
> K2XX
>
> Rick Stealey <mailto:rstealey@hotmail.com>
>> Friday, June 20, 2014 12:10 PM
>>
>> 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
>>
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