Transmission / Overdrive: T9 Backup Light Switch

[JohnM15]

I added a backup light switch to my T9:



Basically, I drilled the lock pin access hole to be taped with a 1/4" pipe tap, screwed in a brass 1/4" pipe section, and mounted the push button switch to the end of the pipe. I made the actuator rod out of a long bolt with the head cut off and rounded on the end that contacts the reverse shift rod. I had to remove the reverse shift rod and grind a detent in it for the actuator rod.

Works perfectly!

BTW, the front of the housing does not have plugs for the shift rods and the parts manual only calls out the three on the rear of the housing. This seems odd to expose the shift rod to the elements. Has anyone made anything to cover the holes?

[(S)]

You did not say what kind of a switch would be so small, round and have a male 1/4 in. pipe thread end?
Part number and application?
So it is normally open, and pops into the detent on the shift rail extending to close?

[JohnM15]

I didn't go into too much detail because folks rarely care much about an old T9.

The switch is a SPST-NO (singel pole, single throw, normally open) push button that I bought from digikey.com. Part number 679-1043-ND:

http://search.digikey.com/scripts/Dk...043-ND&x=0&y=0

Data Sheet:

http://www.apem.com/pdf/1200M-MR-B.pdf

The switch does not screw into the pipe. I have a female/female coupler to mount the switch. The coupler is drilled out to fit the diameter of the switch bushing and have two set screws holding the switch in the coupler. The push button on the switch contacts a rod that I made from a bolt. The rod extends into the transmission housing through the pipe and contacts the reverse shift rod. I plan to encase the switch in heat shrink to help protect it from the elements.