just got an instrument cluster from the junk yard, i know the speed-o works cuz i put a drill on it and the miles move n whatnot. i made sure i connected the speed-o cable and connectors....

can the sensor on the transmission be the problem??

also my dad has an 86 Monte, same prob with him except that his speed-o needle will move when hes in neutral.....can it also be the sensor?

thanks for n e help

 

There is no sensor, its a small plastic gear that is driven by a gear in the transmission. Take it off and see what condition the gear teeth are in. it's simple to remove. You will lose tranny fluid though.

 

it could verry well be the VSS. thats the sensor that goes into your tranny by the drivers side... ill see if i can get a picture for you. does your SES light come on? when my sensor went, it would go on me while i was driving... just drop to zero, and sometimes the light would come on, and sometimes it wouldn't. then all of a sudden, the speedometer would work and the light would go away. replaced the VSS unit and all is fine

 

What Tire said.... no sensor, at least not in the tranny. The older 3rd gens used a traditional speedo cable to drive the speedometer. Somewhere along the cable's length they patched in a VSS for the computer (I think it's actually under the dash somewhere) but the cable actually drives the speedo just like cars going back to the 1940s. Might want to take a trip to the local dealership and have a look at their speedo parts diagrams to see how the system lays out if you don't have a factory shop manual for your car.

 

SES sensor?

 

If it is cable driven the metal clip that holds the plastic gear in place on the tailshaft of the tranny may have fallen out causing the gear to slide out of place on the tailshaft. I've had this happen on two third gens now. On an auto its really easy to get to, just drop the driveshaft and pull the four bolts that hold the end of the tranny case on, on a five speed its quite a bit more complicated but can still be done with the tranny in the car.