"Purchase a TB-105 thrust bearing. I got mine from R&L Electronics for around $25. Works great with that rotator. I have some info on my website (
www.ad5x.com) on how to install that thrust bearing.
Phil - AD5X"
I agree with Phil. Get a TB 105 bearing and use it wit, and it will be fine till you can find a bigger one. the MA5B is an amazing little antenna and you will be amazed at how it works. If you run a 10 foot mast in your roof tower with a set of guys at the thrust bearing you will be in pig heaven.