I think I have the wrong speedometer gear...

[Grec]

1973 Rallye Challenger.

Car has been converted from 340/auto to 440/4-speed.

My odometer is off approx 20-25%. I know this from driving exactly known distances and finding it to be off that much.

I suspect that there are different speedo gears for auto and manual trannys and that the guys who did the conversion never switched it over.

What do you think?

Thanks.

[71340RT]

Yes you have the wrong gear installed in the transmission. Just need to switch it to the correct gear for your cars rear end ratio.

[Chryco Psycho]

Autos & manulas use the same gear but it is probably the wrong tooth count or you changed tire size throwing it off

[MEK-Dangerfield]

I know Year One has a chart in their catalog to help you. You need to know your rear tire diameter, and what gear ratio you have in the rear. The chart migkt not be dead on, but it will get you close. (It was one tooth off on my car). If your speedo is reading too fast, then you need a gear with more teeth in it.


  Mike

[tactransman]

   Here is a pretty good link on this subject.                                                    http://www.moparts.com/Tech/tech/pages/speedo.html
                                                      
   

[Grec]

That's perfect.

Thanks guys!