PROBLEM WITH SPEEDOMETER

[Brads70]

Why don't you post a wanted ad on here? Might get a used one cheaper?

Because I prefer buying a new one

ok 

[Strawdawg]

https://www.ebay.com/itm/Dodge-Jeep-33-Tooth-Speedometer-Gear-Long-Shaft-with-oring-and-seal/153249005446?epid=22005795561&hash=item23ae5a3f86:g:g9sAAOxygPtS6osA:sc:USPSFirstClass!76837!US!-1:rk:2:pf:0

[THE ZUKE]

https://www.ebay.com/itm/Dodge-Jeep-33-Tooth-Speedometer-Gear-Long-Shaft-with-oring-and-seal/153249005446?epid=22005795561&hash=item23ae5a3f86:g:g9sAAOxygPtS6osA:sc:USPSFirstClass!76837!US!-1:rk:2:pf:0

Yeah !! Really great thank's for the link 

The pinion is ordered 

[THE ZUKE]

News 

I have changed the speedometer pinion gear chart and the problem was the same.

I bought an original speedometer tested to one of my american Facebook friends. 

Cost 40$ + shipping USPS 52 $  for a reproduction it wil be 500 euros (cost + shipping + taxes). 

[bc3j]

I have a 235/60-15 rear tire (26.1") with a 3.23 ratio, a 727 trans and use a 34 tooth speedometer gear and the speedometer is right on after checking it with a gps app on my phone. My '70 FSM shows a 34 tooth gear for an E60-15 tire (also 26.1") with a 3.23 rear. I understand there was a change in later years FSM.

[RUNCHARGER]

GPS your actual speed against the speedo. Then do the math to find what percentage it is out. Then you can calculate what speedo gear you need.

[THE ZUKE]

I have a 235/60-15 rear tire (26.1") with a 3.23 ratio, a 727 trans and use a 34 tooth speedometer gear and the speedometer is right on after checking it with a gps app on my phone. My '70 FSM shows a 34 tooth gear for an E60-15 tire (also 26.1") with a 3.23 rear. I understand there was a change in later years FSM.

With this, it will be better to calculate. 

My car has a yellow pinion, the old was yellow too but my speedometer is dead.

[bc3j]

I don't know when the FSM changed. I forgot if it was Alan, Cudy Cody or Wild who mentioned that there was a change in the manuals. Apologies if I got it wrong. I was always stumped by the different charts so I stuck with the '70 one and it was correct for me. Here's the 1970 page.

[Spikedog08]

Ok I have read this thread and just want to confirm which pinion gear I need . . . tire size is P255 / 60 R15 . . .appears that my tire diameter is 27 . . at first I thought I needed the Yellow for a 3.23 gear in the dana . . . thoughts? 

[Brads70]

Ok I have read this thread and just want to confirm which pinion gear I need . . . tire size is P255 / 60 R15 . . .appears that my tire diameter is 27 . . at first I thought I needed the Yellow for a 3.23 gear in the dana . . . thoughts?

Looks like a 31 or 32 ?

[1 Wild R/T]

FWIW the charts are all based on a properly calibrated speedometer head.... If you can accurately drive the speedometer head you can check calibration yourself..... 1,000 RPMs should read 60 MPH...

[303 Mopar]

Ok I have read this thread and just want to confirm which pinion gear I need . . . tire size is P255 / 60 R15 . . .appears that my tire diameter is 27 . . at first I thought I needed the Yellow for a 3.23 gear in the dana . . . thoughts?

Looks like a 31 or 32 ?

32 according to Brewers, and @Dan Brewer seems to know his stuff.

[RUNCHARGER]

I haven't used a chart in about 30 years. If you have say a 245 or 265x60x15 just do 10X your gear ratio. Hence a 32 tooth for a 3.23. The number crunchers and parts book beaters tell me I'm wrong but a 31 against a 32 tooth isn't going to get you exact anyway, it might be a difference of 1MPH and these old speedos aren't the same car to car anyway.

[Spikedog08]

Well I still need to make a change as at one point there were 4.11 gears in the hardtop and now I'm at 3.23's . . . On the highway felt like I was doing 77 or 78 and speedo only said 70mph.  Just need it to be somewhat close . . .