The Stovebolt Site Forums The Shop Area Engine Shop Switches on Saginaw 3 Speed Transmission

I'm trying to identify a switch that is near the front shifter shaft on a Saginaw 3 speed in my old beater 1973 G10 van. I pulled the transmission to replace it with a junkyard fresh unit from a newer van. When I attempted to pull the plug off of the switch, the whole top broke off (it might have been integral with the wire before I fixed it!). I'm not even sure of what the switch does. It's not the backup light switch because I've replaced that one before and it is near the rear shifter shaft. Someone at the parts store told me that it might be a neutral safety switch, but I've always been able to start the van in any gear, so I have my doubts. The new transmission is out of an 82 model truck and is identical except for having metric threads on everything. It has the same switch, but it's also broken off. Any offered wisdom would be appreciated since my manuals have no information either.
Thanks,
Marshall

Marshall, you might want to check a factory shop manual, but I seem to remember that my '72 C-10 with a Saginaw 3-speed had a switch that prohibited vacuum advance unless the transmission was in high gear.

---> Bill

Bill,
Thanks. You're right. I had to go to a Chevy dealer to get the answer, and it was no big suprise that the switch wasn't available. I just taped it off. The wierd emissions setup that they used on this model doesn't use ported vacuum for the distributer. I think I'll be doing some sorting out and component changes. The good news is that other than dieseling when I shut it down, it runs great and shifts like new.
Marshall