'speedometer pinion' gear vs computer flash

[jeepsquire]

With the bigger tires I know the speed is off, doesn’t concern me as much as the performance, fuel ratios, etc.

I know that I can either replace the 'speedometer pinion' gear or take it in to the dealer and have them change it in the computer.

Doesn’t the computer just get the speed from the 'speedometer pinion' gear? 

It seems like it should but I don’t know for sure and wanted to make sure that I was fixing everything and not just fixing the speedometer if I replaced the gear.

 

[Rubi04TJ]

Not sure, but i think you may have mixxed info. Rubicons from 03 (becuase of the rocktrack transfercase) have no speedo gear, these are the only wranglers that i know of that you can do a computer flash. Everything else i belive is driven by the gear.

 

[jeepsquire]

I called the dealer and they said that they do it for the "98 and that it was $80.

I guess a bertter way to ask my question is does the signal from the gear go to the computer first and then the speedo, or straight to the speedo?

 

[Rubi04TJ]

well in that case, i don't know what you want to do, but the speedo gear is only 15 dollars or so, and a 2 minute install.
You can also take a look at this.
http://www.superlift.com/accessories/truspeed.asp

a lot of hte rubicon guys use this because some of the tire vs gear ratios can't be flashed.

 

[JeepinMaxx]

I

With the bigger tires I know the speed is off, doesn’t concern me as much as the performance, fuel ratios, etc.

I know that I can either replace the 'speedometer pinion' gear or take it in to the dealer and have them change it in the computer.

Doesn’t the computer just get the speed from the 'speedometer pinion' gear?

It seems like it should but I don’t know for sure and wanted to make sure that I was fixing everything and not just fixing the speedometer if I replaced the gear.

JeepSquire - I had the same issues when I swapped in 4.56 gears and 33"s

What gears and what tire size are you running?

I'll try to attach the chart I used for my speedo gear.  40 tooth worked for my gear/tire combo



[attachments are removed after 60 Days]