Speedometer Question?

[JeepinSE]

I have a 2001 Jeep SE with stock ratios (4.10?) and just put on BFG AT KO 31x10.50x15 tires.

This site leads me to believe that I need a 36 tooth speedo gear.
http://www.gojeep.rockcrawler.com/How%20to4.htm

This site says I need a 38 tooth speedo gear.
http://jeepin.com/features/speedogear/index.asp

:-? Which one would be right for my set-up?

Please help. Thanks!!!![addsig]

[Bounty__Hunter]

The SE came with two different axle gear ratios in '01, 4.10 if you have the 5spd, 3.73 if you have the auto. Use the same charts with either of those ratios and hopefully they agree.[addsig]

[JeepinSE]

Thanks for the response Bounty, but if you looked at the web sites I listed you would have seen they don't match. That's where I'm getting confused. I have scoured the internet and all I find is other charts that have the same figures as one of the web sites I listed. It either says 36 teeth or 38, but there is no consensus.

I have the 5-speed, and my ratio is 4.10.

The charts still give me different numbers. One says I need 36 teeth, the other says 38.

The one with the 38 teeth is for a 4.11 ratio. It is the closest thing on that chart.

Does anyone out there know what the correct speedo gear is?
[addsig]

[Jonzey4x4]

4.10's w/ 31x10.5's need a 36 tooth speedo gear.
http://www.jeepsunlimited.com/zj/speedo/speedo.htm

edited by: Jonzey4x4, May 02, 2003 - 07:43 PM[addsig]

[K_K_PSI_GUY]

Okay, thanks for bringing this up. What is the deal with gear ratios, and tire sizes? I beleive I have the same size mentioned below on my 95 Wrangler( stick with 4.0 6 cyl.) Should I have asked the people at Firestone to do something to the gear ratio, or does it not matter with these tires, or do they do it on their own. I'd just like to get cleared up on this issue that has been bugging me for a while, but I always forgot when I got logged on here.[addsig]

[Bounty__Hunter]

You likely have the 3.07 axle gear ratio with that setup, and it's up to you to change the speedometer gear to correct the speedometer. It's located in the tailshaft housing of the transfer case.

I posted the above 'cause you didn't make it clear wether you have the 3.73 or 4.10 gears. After the change, I'd confirm the accuracy with a GPS. I'm always loaning out my GPS to friends to confirm how far off their speedo is.[addsig]

	Transfer Case Mounted behind and driven by the vehicle transmission, the transfer case transmits power to the front and rear driveshafts in 4WD Jeep vehicles and offers high and low range.