[TowerTalk] Replacement Thrust Bearing

[K7LXC--- via TowerTalk]

>  I am overhauling my rotator and thought it would be good  to replace my 
thrust bearing also.
I have the Rohn TB3 bearing now.  It  has been in use for 18 years and 
feels pretty rough.
 
    That's pretty SOP for a mature TB3. What are  you using the tb for? If 
you've got all of your mast and antenna on it  taking the weight off of the 
rotator, that's one thing. If you're just using it  as a bushing to help 
with horizontal forces, that's another. 
   
    With case 1, another bearing might be the way to  go. The rough races 
will only get rougher (steel ball bearings in an aluminum  race will only 
take so much abuse).
 
    With case 2, it's probably FB since you're not  asking it to do much. 
 
>  Im thinking of going with a different bearing this time with a steel  
body and greased. (grease fitting)  
Looked thru the archives on tower  talk to find out what others have used 
and can?t find much,
on this type of  replacement and I know the bearing supply houses have 
them, just haven?t  
pursued searching with them yet.   I would like to know what  others have 
used.
 
    I haven't seen a decent bearing like you're  describing that'll work 
outdoors. US Tower uses a pillow bearing that's designed  for indoor use. 
There's an Allen screw that holds everything and over time the  Allen screw 
rusts terminally and you have to drill it out to do anything with  the bearing 
or mast. Not recommended. 
 
>   Array Solutions has their model TB2 which is this type of  bearing but 
it only has a two hole flange for mounting.  
 
    Again, even if you have the bearing holding the  weight, you're still 
not asking it to do much. I don't see any way to secure the  mast from the 
picture. If it's got the aforementioned Allen screw, you could be  screwed as 
well. 
 
    IMO thrust bearings are only marginally useful  since you want some/all 
of the mast/antenna weight on the rotator or just have  it act as a bushing 
so you might rethink the TB issue and whether you even  need one. 
 
Cheers,
Steve    K7LXC
TOWER TECH