Greasing a Model A horn?

katy

Well-known member
Should the "wobble wheel" on the end of the armature shaft have grease on it, where it conacts the dimple of the diaphram?
 
I say no. Anything that can gum up the ability of the motor to spool up to full RPM quickly is right out.
 
Been doing it for 30+ years when I have worked on a horn. Never an issue and it seems to hlelp the RPM to your point above for the tone of the horn. Just my experience however.
 
The horn is what you'd call a "light-duty" component. If you drove your car every day and sounded the horn twice a day on average, at the end of the year, the horn motor would have 12 minutes of use on it. I think it was for this reason that they didn't bother to grease the ratchet at the factory, despite it qualifying as a metal-on-metal sliding contact.

That said, there are good reasons to grease the ratchet:
  • Reduces energy lost to friction, so the horn can be louder without the ratchet being slowed/stopped by the diaphragm
  • Reduces wear on the contact surfaces, which is good in this era of parts shortages
  • Helps protect surfaces against rust

The horn rebuilders I know grease the ratchet. If you didn't grease it, you'd probably be fine too.
 
I'd spray the horn motor ratchet with a coat of dry lube like Moly Koat and leave it at that. Too much lube and the diaphragm won't vibrate as well. That vibration is what makes the noise. The louder the better.
 
I have a big can of graphite grease, I'll try a smidge of that.
Thanks all.
 
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It only mentions lubricating the armature in the Service Bulletins.

This is definitely a practice that has evolved out of the "folk tradition" of Model A maintenance rather than coming from the manufacturer. Doesn't mean it's bad, though. The Ford Service Dept wasn't trying to preserve these for 95 years.
 
This is definitely a practice that has evolved out of the "folk tradition" of Model A maintenance rather than coming from the manufacturer. Doesn't mean it's bad, though. The Ford Service Dept wasn't trying to preserve these for 95 years.


Whatever, just passing along info...
 
I put a smidge of graphite grease on the "wobble wheel", works great.
Does anyone know the proper thickness of the gaskets for the diaphragm? Or does it matter? I made a couple because they were missing.
 
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