So, long story short. Last October, my speedo died on my 91z. I figured it was the vss so I ordered a new one. I never had a chance to replace it, and then the car was in an accident. Well... 6 months later, I have the car back. I went to replace the vss this week and there was no gear attached to it. I tried to look in the tranny housing and there is no sign of it. I know it is a red 37 tooth driven gear and I can get one quickly. My question is what do I have to worry about/do with the gear that is somewhere in the tranny? Have any of you had this happen?

 

Nopo ! NEVER heard of a speedo gear just vanishing before !


Think maybe one of your gear-head buddies stole it to screw with you ??


I'm not sure how the entire Speedo gear could just vanish without a trace, and not sure what to suggest !!! I think I'd probably remove the tailshaft housing from the case,......... just to be SURE I couldn't find any plasic. Tiny schards of shaved plasic pieces would NOT be good for the tranny !

 

Well, I didnt find anything similar on TGO but was looking through Google and other GM cars/trucks have had the speedo gear split and fall off of the VSS. Dont know if this is my case but with a 23 year old plastic part, it is possible.

 

Found it. After pulling the vss again, I fished aroun in the tail housing and I found what was left of my speedo gear. It was split in half from the corner of the shaft hole. New gear and vss installed, works about 95% of the time. The other 5%, the speedo drops to 0, SES light comes on and car runs like s***.

 

I will refer you back to this post. Check the drive gear and be prepared to replace the driven one again.

 

There were no significant pieces missing from the speedo gear. I drained the trans fluid just in case and found a few tiny pieces of what looked like maybe a piece of a tooth. I didnt bother to check the drive gear. Guess its time to pull the tail.