im sorry if this has been answered before but i searched and couldnt find an answer

what actually causes the speedo driven gears to get chewed up i replaced mine about a month ago and it went out tonight. i thought it had gone out about a week ago but it started working again the next morning. if some one knows what causes em to get chewed up so i can hopefully fix mine before i go through another gear

 

Are you sure the gears are being chewed up?

I had the intermittent speedo problem on my 88 GTA and found out the spring clip that holds the gear to the tail shaft was missing. That caused the gear on the speedo sensor to not make a connection. The other thing could be that the speedo sensor is bad and not spinning correctly. Replacing the sensor easy, the clip a real pain in the you know what.

 

Well It didn't work when I got the car. I replaced the gear and re mounted the clip and driven gear I'm going to double check tomorrow at work wether the gear is stripped again or not

 

Can you compare the VSS to another? If it is dragging or binding, that could hurt the gears. On mech. speedo cars, everything up to the speedo can do that.

 

checked it out today at work found the drive gear had come loose the clip has disapeared into the trans and the driven is chewed smooth i went to the local gm dealer and based on what they show i think it had the wrong driven gear anyway it has a green one and i think it should be light blue for an 89 formula 350 that is stock with a 9 bolt but im not sure of the ratio in the rear

 

Well here is the site I used to figure out what gears I needed for my 88 GTA.
http://www.transmissioncenter.net/sp...n_______va.htm
Or just search speedometer gear calculator on Google or you search engine of preference.