[TowerTalk] Best Grease for Rotor bearings ?

[jcjacobsen at q.com]

Doug has a question: 
----- Original Message -----



Would either of you gentlemen please provide for me the instructions from Rohn that states that their TB-3 thrust bearings are to be run dry. I know that they are sold dry. I am looking for facts from Rohn that say that these bearings should not be lubricated. I am not interested in any information except from Rohn. 



Doug 



> -----Original Message----- 

> 

>I use White Lithium grease. Some rotator manufacturers are using it 

>now. For thrust bearings...It all depends. ROHN says to run theirs dry. 

> 

>73 

> 

>Roger (K8RI) 

Doug, 

#1. I do know that my TB-3 has been in the air since 1991, unlubed, and is still going strong. 
#2. I seem to remember that there was a rather limited instruction sheet with the new bearing that said don't lube, but I'll be dipped if I can find it in my files. 
#3. The fact that it was built WITHOUT a grease fitting, and would have to be removed from the tower and disassembled to grease it says volumes in my book. 
#4. The archives show a couple of entries from YEARS ago saying not to lube the bearings. They weren't designed to be lubed. One of them is from Steve, K7LXC, who should know if ANYONE does: 

<SNIP> 


From: K7LXC at aol.com 



In a message dated 97-01-12, you write: 



>Since this is an open design for a bearing and it's 

>turning slow, one would think it shouldn't need any 

>lube. Right or wrong? 

> 

The LXC Prime Directive for tower and antenna projects is to "do what the manufacturer says". The corollary to that is "don't do what they don't tell you". In other words, Rohn didn't say to lubricate the TB-3 so you shouldn't. Since it only turns one RPM, there's not much that is going to happen to it during normal use. 



Lubricating it will actually cause premature failure because the grease will hold onto any contaminants that are blown through in the wind (dust, rain, etc.). The same is true for crankup cables: do not use a grease on them. There are special lightweight cable lubricants that you should use that will soak into the cables without attracting contaminants. In the case of Rohn thrust bearings, leave 'um alone. And like Rod, N4SI, says, if in doubt - throw it away and get a new one. 



Steve K7LXC 




<SNIP> 




I hope this helps. 





Good luck with whatever project you have going. 




73 

K9WN Jake