Speedo is still off

[Bstahl875]

2002 TJ. VIN number says 3.07 gears. Diff says 3.77. Installed the correct gear for the speedo (tire size and gears) and my speedo is still off. Is it possible someone put different gears in it and it still says 3.77….meaning they didn’t mark it somehow?

Is pulling it apart and counting the teeth difficult? Could I do something else?

 

[Foxhound67]

2002 TJ. VIN number says 3.07 gears. Diff says 3.77. Installed the correct gear for the speedo (tire size and gears) and my speedo is still off. Is it possible someone put different gears in it and it still says 3.77….meaning they didn’t mark it somehow?

Is pulling it apart and counting the teeth difficult? Could I do something else?

Pull the cover and count the teeth is one way to get the exact ratio, or put a chalk line on the driveshaft and see how many revolutions it takes to rotate the tires once. That would get you a rough idea.

 

[KennethS]

Never heard of 3.77 gears. Mine has 3.73 which is a common industry ratio.

If you pull the diff cover the number of teeth on the ring and pinion is stamped into the outer edge of the ring gear. No need to count teeth as the pinion teeth are hard to see and count accurately.

 

[TheBoogieman]

Diff says 3.77. Installed the correct gear for the speedo (tire size and gears) and my speedo is still off.

Did you?

 

[JMT]

2002…my speedo is still off.

Is pulling it apart and counting the teeth difficult?

2002 was a weird year. Please keep your Speedo on. No, you can’t pull it apart and count the teeth.

 

[KennethS]

This thread has lots of information:

https://wranglertjforum.com/threads/how-do-i-determine-my-axle-gear-ratio.72/

This image is a 3.73:1 ratio ring gear. The 41-11 is the number of teeth on the ring and pinion gears. 41 divided by 11 equals 3.73

 

[Bstahl875]

I put a piece of tape on the drive shaft and had my wife count as it went by. 4.5 times so 4.56 gears

 

[freedom_in_4low]

I put a piece of tape on the drive shaft and had my wife count as it went by. 4.5 times so 4.56 gears

 

[Bstahl875]

View attachment 449218

Yes! I am 100% good with that