Can the speedometer (tire size) be calibrated using Witech on a Jeep JK?

Joshua Mechanic Nebraska Posted   Latest  
Resolved
Drivetrain
2008 Jeep Wrangler X 3.8L (1) 6-spd (NSG370)
Speedometer Incorrect

Installed a new engine, lift kit, 4.10 gears, Eaton Truetacs, and 33" tires on a 2008 Jeep JK, manual transmission. I am wondering if I can change the tire size with Witech so that the speedometer will read correctly or if an aftermarket programer is needed. I hooked up Witech and looked around for a bit I didn't see an obvious way to change the tire size. Thanks in advance. 

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Justin Technician
California
Justin
 

In the early days they called it pinion factor not sure on your make and model

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Richard Instructor
Florida
Richard
 

I’m pretty sure the witech will only allow stock tire size Adjustments. You’re gonna need aftermarket

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Benjamin Diagnostician
Tennessee
Benjamin
 

I am positive you can only select stock tire sizes. You will need aftermarket/tuning software to correct non-stock gear ratio/tire sizes.

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Glenn Owner/Technician
Texas
Glenn
 

With all those modifications, it would be cheaper using a GPS or a cell phone ap with voice speed speed readings

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Charles Technician
California
Charles
 

Witech only has a small selection of stock tire sizes selections to change and it does not allow any change to the gearing. Procal from AEV works best with that kind of setup, you can fine tune the speedo, ESP and tire pressure settings. Once you use it it's married to that vehicle and will only that vehicle that vehicle from then on. aev-conversions​.​com/product/procal…

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Joshua Mechanic
Nebraska
Joshua Resolution
 

Thanks for the info, that is what I needed to know.

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Sisco Owner/Technician
Vermont
Sisco
 

Going down in gears and (slightly) up in tire sizes, shouldn't be that far off-if you can change it, look for Rubicon specs, cause pretty sure that's the combo they came with. Used a Hypertech recalibrator in my '11 Ram to fix it back then.

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Randy Technical Support Specialist
Ohio
Randy
 

I believe Bartec has a tool that will do that.

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Kody Service Manager
Oklahoma
Kody
 

We just installed a lift on an 08 jk and we’re able to reprogram the speedo with a snap on scanner. Not sure of the gear ratio change but I would think that 4.10 is probably a stock option you could set with the pinion factor settings also.

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