My speedo and odometer were not working, so I got a replacement vehicle speed sensor (at the junkyard, but I reused my gear). When I hook it up and spin the gear, the speedo works.

But I can't for the life of me figure out why it's not working when installed in the tranny. I've tried repositioning it (turning the assembly so the gear on the VSS is closer to the teeth in the tranny), but nothing. Everything between the old and new parts appears to be the same.

It's as if it isn't contacting the gear in the tranny. I noticed when I looked in the opening in the tranny that there is a little hole opposite. Is there supposed to be a pin that holds the VSS gear in place?

Any ideas?

 

There should be a nub on the back of the speedo gear that fits into that hole in the tranny housing. Without that nub, the gear is free to get pushed away from the worm gear in the tranny.

 

Oh, one other thing. On the plastic speedo gear is a 2-digitnumber. The plate that holds the gear into the tranny has numbers stamped into it, 90 degrees apart. The range of numbers on the platethat your speedo gear number falls into should be at the 6:00 position (straight down) when the plate is installed and fastened down. If you installed the plate wrong, the nub could've broken off. In that case you'd have to get a new plastic speedo gear from the dealer with the same 2-digit number on it.