Cole

I need to replace my vehicle speed sensor, but I don't know which one I need? I have an '86 Firebird with a 700r4. My speedo gears are a 15 tooth (gray) drive gear and a 41 tooth (yellow) driven gear. All of the parts places have them listed by RPO codes, and I don't know which to get. Also, does anyone know what other years or makes of cars used the same VSS? Thanks

Vader

Do you know what rear axle and ratio you have?

If it's a Borg 2.77, the RPO numbers relevant to the VSS would be:

D9A
E5Z
E9Z
G80
GM3

Cole

I have a 10-bolt that originally had a 2.73 posi. Now I have 3.42's. I don't have the rpo sheet though, it was missing when I bought the car.

Vader

Sorry - not a clue, then. A dealership parts department should be able to help you. I said "should" since they can find the information if they really care to.

Dave Y

what size tires?

if you have 245/50R16's , then you need a 15 tooth and a 40 tooth

for more, try here
http://www.700r4.com/speedoCalc/speedocalc.html

jasonbennett

look for rpo md8 or md9 something like that. that will tell you which one to buy. only get the ac delco one. the others don't work