I am running a 33" tires with 4.10 gears on an automatic tranny. I need to have my speedo calibrated. I am hearing a lot about other options such as Superchips, Skyjacker Truspeed, and orange (35 tooth) speedo gear.
Which one will work better? Anyone have used any of these?
01-21-2011 11:54 AM
I have 33" wheels and 4.10 gearing. I put in a 36 tooth speedo gear and its right on. You can get the speedo gear from Quadratec but its like $40!! I bought mine used off EBAY for 12.75 shipped and it took two seconds to change. I would recommend that, I'm not sure the speedometer is controlled in such a way that a tuner would fix it, at least I never heard of that as an option!
I just changed mine this week as well. It went really fast except that I put it in upside down the first time and it didn't register. I don't know if an Auto will make a difference but I wouldn't think so since the speedo gear is in the back of the transfer case.
Here is another link that will help in installing the gear.
All you need to do to recalibrate your speedometer is to replace your speedometer gear with a 36 tooth speedometer gear. Here's how to do that: Changing Your Jeep Speedometer Gear
Replacing the speedometer gear can be done in less than 5 minutes.
01-21-2011 12:45 PM
Only Rubicons require electronic speedometer add on boxes to calibrate.
01-21-2011 01:01 PM
Ok...I am confused. I see some chart says 35 tooth but morris4x4 chart says 36. Which one should I go with?
01-21-2011 01:21 PM
There are several known inaccurate charts floating around out there. The chart I gave you is accurate and has been gps verified.
01-21-2011 01:54 PM
Thank you Jerry for the clarification.
01-21-2011 03:16 PM
My set up is the same as yours and a 36 tooth gear is spot on per my GPS
05-19-2016 08:53 AM
I am going from 30 to 39. Is that a problem? I am guessing whoever put 33's on never changed the gear. should I do 36 like everyone else? Also, I am hoping this will get my speedometer/odometer to work...
05-19-2016 10:31 AM
The correct speedometer tooth count depends on your axle ratio, there's no need to guess on which one to use. The chart in this website is dead on, use that to determine which speedometer gear is correct for your tire size and axle gear ratio combination.
And if your speedometer isn't working, odds are whoever last messed with the speedometer gear housing didn't get it rotated far enough to cause the speedometer gear and the pinion gear underneath it to engage reliably.
05-19-2016 11:33 AM
My TJ was a 34 tooth with 4.10 and 33's , my wife's XJ 4.10's and 33's is a 34 tooth. Both dead nuts on, verified with a GPS and Golden Eagle radar. When I went to 35's I went 39 tooth.