I'm kinda having a hard time with this one. I've swapped the sensor and swapped the plug (since it was corroded) and still nothing. I know that stuff is good because we can turn the car to run and spin the gear on the sensor by hand and get the speedometer to work. It would seem that maybe the gear on the speed sensor isn't touching the one in the tranny? Is there a way to confirm this? It looks like the gear is there so I don't know. Kinda stumped.

 

I have seen the transmission piece itself fail, but only in rare cases. How did you switch the plug?

 

Took it off and soldered on a new one. After that is when we tested it by hand so I know it works. If it's not touching, is it possible that I have the wrong gear attached to the speed sensor? As in will another gear match up to the sensor but not be long enough in the tranny? When I got the tranny, it didn't have a sensor and I put one in that I believe is a B series, but I can't be 100 percent positive.

 

You could have just de-pinned it. Check the pins in the plug and make sure they are all making proper contact with the pins in the sensor. Good luck!

 

If they weren't in contact, when we spun the gear by hand, wouldn't we still get nothing on the speedo? The speedo worked when the gear was being spun by hand so everything in the plug should be in proper contact right?

 

Yes, so I think you just answered your initial question...It must be the part inside the transmission that is not working properly. You eliminated everything else by testing it by hand.