[TowerTalk] thrust bearings

[Jim Thomson]

 The TB-3 (and TB-4) are both aluminum races with  steel ball bearings. 
It is very common for older TB's to have the rumbling you  describe since in 
wind gusts, the steel bearings can get pounded into the  softer aluminum 
races. This means the bearing is on its last legs. I wouldn't  reinstall it. 

## if she doesn't  reinstall it, what is she supposed to replace it with ?    





Well, if you were just going to use it as a bushing without  tightening the 3 
bolts, it'd last for years.

## Then u end up with a sloppy fit..and mast will wobble...esp a tall
one.  Actually that array solutions swinging side mount uses a 1"  THICK
some kind of plastic... like uhmw..but black.  If the hole in it was say 
2.004... instead of the typ  2  1/16 [ 2.0625"]  then no slop. 

##  A thick, treated wooden bearing would work too.   I wouldn't use
a steel, fixed tube.. unless well lubricated.. like roger is planning.
Rotate a galvanized mast on inside a fixed tube.. and u will probably
tear off the zinc plating on the mast...eventually. 

Jim   VER7RF  




 The actual value of a thrust  bearing is the 
subject of some conjecture since most or all of the weight of a  mast and 
antenna array should be on the rotator. 
 
Cheers,
Steve    K7LXC
TOWER TECH