[TowerTalk] US Tower seized gearbox

[Robert Harmon]

Jim,

The W300 is a worm drive reduction gear.  I have a similar one on my US 
Tower
90 foot motorized tower.  The first thing I would do is take out the 
fill plug on the upper
side of the gearbox and see if the lubricating oil is still there. It 
sounds like it ran low
and overheated.  Is there any noticeable leakage from the seals ?
If it is low on lube oil I would fill it up to the fill hole until it 
starts to run out then
put the plug back in.  Then try momentarily alternating up and down with 
switch and see
if it gradually frees up.  These worm gear reduction gears need to have 
the lube oil
changed periodically.  The residue from the sliding worm gears gradually 
contaminates
the lube oil.  What I did on mine is convert over to Mobil synthetic 
lube oil.  It runs cooler
and there is less wear compared to the petroleum lube oil.  Still need 
to change the lube oil
periodically though.  Hope you can get it resolved.  Let us know how it 
goes.
(If this doesnt work, I would take out the lower drain plug and 
completely drain the lube oil.
then fill the gearbox with penetrating oil and let it sit for awhile and 
try again. Before doing this
you might call Hub City and go over this with them they can recommend 
the best penetrating oil to use.  It might save you an expensive crane 
process.  The guys at Hub City are great to talk to and very helpful )

73,
Bob
K6UJ

On 1/28/16 7:59 PM, James Denneny wrote:
> The Hub City W300 gearbox on my US Tower 85 ft rotating mast appears to have
> seized after 12 years.  Un fortunately the tower is at the 55 ft level and
> will neither raise nor lower. Fortunately, it is at a safe height with
> respect to wind.  Unfortunately, I am uncertain how to get it down to
> repair/replace the gearbox. The lifting cable drum mounts on the gearbox
> output shaft.  I cannot pull the gearbox as the cable drum system is what
> keeps the tower from freefall. I do Have the tiltover fixture.  There is a
> SteppIR DB-18E yagi at the top.  I am resisting bringing in a crane to
> support the tower. Any suggestions?
>
>   
>
> Thanks
>
>   
>
> Jim K7EG
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>