Speedo driven gear question.

[Turbo6Smackdown]

My car came with a 140mph speedo overlay w/ the gear reduction thingy screwed inline on the speedo cable/transmission connection. When I peeled the overlay off and removed the gear reducer, it changed but not enough apparently; my mph is 10 off at speeds below 50 I think, and the error changes (can't remember the percentage) above 50 but I'm mostly concerned with below 50 accuracy anyhow. Could the previous owner have changed the driven gear for this mod? I'm initially thinking no because there was an external gear reducer on there. I figured that since I removed it I'd be back to stock. What am I missing? I see I have a specific RPO for my driven gear but how do I know which color goes to which RPO?

 

[turbo nasty]

You could have the wrong speedo gear on the governor in the trans as well. Should be orange

 

[Turbo6Smackdown]

How do I check this?

 

[INEEDAGN]

Remove the 10mm headed bolt that holds the speedo bullet in and remove the bullet/driven gear assembly. Hopefully it's not stuck. If it is stuck you'll have to pull the pan and gov cover to know what you have. If you have a smartphone try to get a clear pic of the governor gear and post it here along with the teeth count on the driven gear and your rear gear ratio and rear tire size.

 

[Turbo6Smackdown]

Speedo bullet?

 

[77 cruiser]

The part your cable hooks to on the back of the trans, it has a 10 mm head bolt holding it on.

 

[Turbo6Smackdown]

I'll try it out. Thanks!