Superkop

Drove her around for a bit the other night, and everything seems nice, runs solid...no speedo action though. And then a check engine light for a VSS code 42. Obviously the "signal" from the tranny isnt getting to these, and before I go to it, I figured I'd ask how many of you had the same issue, so as to save some wasted time. I am pretty sure the cable is fine(will be testing that theory with another set of eyes in the cockpit...I'm good but not THAT good), and I am betting its the speedo cable adaptor/gear inside at the trans thats not working. Also, the VSS location in my car (87) is no longer supposed to be behind the speedo, but now "in the transmission" according to Haynes. This helps my opinion that its the unit on the trans, because if the speedo itself was bad, the VSS would still be reading the speed from the cable turning, no?

vetteoz

iTrader: (13)

If you have the trans mounted VSS then you don't have a speedo cable
You are correct that if the gears may have stripped or the clip that holds the gear on the shaft is broken
the VSS will not be driven but also may be a simple as a broken wire from VSS to speedo and ECM

Mad_IROC-Z

haynes is stupid. Their manuals are a waste of money. Put it in the toilet incase you forget to reload the TP.
The electricly driven speedo did not come out until 90 (unless you have the early digital). The VSS will be behind the speedo picking up pulses from the blades on the back of the speedo that also drive it.
Don't worry about the code, look into why the cable driven speedo is not working. Maybe its as simple as it unscrewed from the tranny.

JamesC

iTrader: (5)

Super, placing relevant info about your car under your name will help in diagnosing problems.

Camaros were equipped with mechanically driven speedos, 82-89. The VSS is on the backside of the cluster. 90+ were electric and the VSS is on the trans tail shaft.

Some Birds went electric as early as 86, IIRC.

If your speedo is mechanically driven, the following link should be helpful:

https://www.thirdgen.org/forums/inte...eedo-woes.html

JamesC

Mad_IROC-Z

I keep forgetting there are Firebirds. In the perfect world I imagine there would only be Camaros... Period!

Superkop

Yeah, I had a hard time thinking it wasen't standard location when I new that I had a cable. Turns out the Speedometer Cable Adaptor needs to be replaced...pull the cable off teh trans, spin the internal, and walla, speedo works. Now to find one I called the local GM place and the parts guy was telling me "theres like seven different ones..."

Mad_IROC-Z

Ok so it was not as simple as unscrewing from the tranny.
Now you need the part that screws into the trans?
Could it be you just need the driven gear?
Wosre but not bad, the drive gear?
You can see the parts here,
http://www.transmissioncenter.net/sp...0gear%20driven
Scroll down the page and you will see the housings that the cable screws to and the driven gear that goes inside the housing and also the drive gears.