I bought a Stewart Warner signal 114-a that supposedly worked,it didn't. I pulled up on the plunger and when it came out of the horn I realized the #4-40 screw in the end was missing (circle at end of plunger) but there seems to be something missing from the gear mechanism that makes it work If you could post a pic of yours I would be grateful.
OK, here we go. Views from every side.
I was given this plunger. It's mostly wrong, but the teeth seem to be right. If you can get some good pictures of yours and post them with measurements, I think I could make one that will work on my horn.
First the measurements
Narrow side of plunger .247 (just under 1/4 inch)
Wide side of plunger .373
Hole at the end is threaded #4 40
"Cut Down"at end of teeth is .300
length of plunger from under the head 3.750 inches
there is a hole in the end of the plunger it penetrates about 1.5"
Teeth are 10 teeth per inch
The plunger and spring are inserted after the "gearbox" is installed in the housing and there is just enough room to install the stop screw so your plunger doesn't come back out.
(I left out the spring for ease of photography.
Excellent! Exactly what I need. You can bet I'll use Lock-tite on that stop screw.