Question on Lionel 151 Semaphore

Plastic.  The reproductions are pretty good, but if the mesh isn't right the gear will either strip or jam.  I usually twist the housing while I'm tightening it until the mesh is just right.  They can be a pain sometimes.  

Jon G posted:

Plastic.  The reproductions are pretty good, but if the mesh isn't right the gear will either strip or jam.  I usually twist the housing while I'm tightening it until the mesh is just right.  They can be a pain sometimes.  

Very good. Thank you for your response. Maybe I'll give it one more shot!

Add a thrust washer to keep the gear from tilting under load?

(Wild guess, mine are ok)

As has been written, the original arms, including the gear were made of plastic. In my experience, the gears on the reproduction arms do not mesh well with the rack that moves the arm.
I've tried a few different ways to improve the mesh, but none of them produced satisfactory results.
I'd like to try Jon G.'s technique of twisting the housing, but I am not clear on what to twist.