Speedo Discrepancy

[Chubbard1904]

My 97 TJ 4.0 is running 33x14 tires and 3.07. We changed the speedo gear to the recommended 26 tooth. I felt it drop down and seat when installing it. However, the speedometer is still reading way off. Is there something I’m missing or need to do differently? The markings on the sensor are aligned for the 26 tooth gear also.

 

[CharlesHS]

My 97 TJ 4.0 is running 33x14 tires and 3.07. We changed the speedo gear to the recommended 26 tooth. I felt it drop down and seat when installing it. However, the speedometer is still reading way off. Is there something I’m missing or need to do differently? The markings on the sensor are aligned for the 26 tooth gear also.

The 26 tooth gear on the chart indicates it is for 32" tires with 3.07 gears.
You will find that most 33" tires are NOT 33" nor 32"; they are actually around 31.5".
Read these responses to a similar post on the Forum which should answer your questions.

https://wranglertjforum.com/threads...meter-gear-calibration-recommendations.79836/

 

[macleanflood]

Scroll down...just discussing this...

Thread 'Incorrect speedometer'

Jan 25, 2025

Hi everyone got a weriod one.

When i got my jeep the po had 30s on it and the speedometer seems to be fair close to true. I upgraded my wheels and tires to 31s without changing the speedometer gear and the speedometer was showing 70 and true speed at 78. I purchases what i believe to be the correct apeed gear (27 tooth) for the 3.07 axle now that it is installed the speedometer is show 4 mph or so faster than true speed. The gear that was taken out is stamped 30. So im not sure what gear i needed or could something else be going on.

• OdinsRoar
• Replies: 28
• Forum: TJ General Discussion

• 

-Mac