Do I Have to Calibrate Speedo Again after Regearing to 4:10?

[ggrjordan]

Just like the question above. Is it necessary to recalibrate the speedometer again even if I already did for 3.73 gears and 245/75/16 mud tires? All I added was the 4:10 gears.

Can it be that the car thinks I still have 3.73 gears in? I want to get all the benefits of regearing and even though I do noticed the difference, it’s kinda slight, almost the same as before. I have to mention that the overdrive off button doesn’t work as smooth as when I had the old gears but was calibrated. Other than that everything is powerful and no complaints. What do you guys think? I’ve been regeared for 2 years now, only calibrated with 3.73 gears and 245/75/16 tires, though.

Thanks.

Jeep Liberty Kj 2002 limited 4wd
245/75/16 Mud tires
4:10 gears

 

[Ian Glass]

Your speedo and odo will be out. Best to get hold of a Garmin watch or Garmin GPS device and find a clear bit of highway. Then drive at all the speeds that you need - say 30, 40, 50 and 55MPH. Also record the odo distance covered and compare that to the GPS distance. Then without going through an expensive calibration process you can make a correction chart for indicated speed vs actual speed. The GPS device will also give you indicated odo vs actual miles covered - useful for calculating actual gas milage! Good luck - it's fun.

 

[Dave_too]

I Understand I am late to this party. You might be able to find someone to tune it, but not all those folks know what they're doing and it's unlikely you'll track down someone who has worked with many, if any 02 Libertys. I think Ian's suggestion is the least risky and certainly the most cost-effective way to go.

 

[CheddarGau]

If you went with bigger tires, then it won't actually be out by much. Stock tires with 4.10 will be out. Bigger tires with 4.10 will get you close if not very close to a perfect "calibration".

 

[derekj]

I just put 4.10's in mine and took it for a drive - gps, scan tool data, and speedo were all within 1km/h of each other with 235/85/16 tires.

 

[CheddarGau]

I just put 4.10's in mine and took it for a drive - gps, scan tool data, and speedo were all within 1km/h of each other with 235/85/16 tires.

I put 4.10 on mine, with 245/70/17 and the park speed display is reads (max)30km/h and my speedo reads 30km/h. I wanted 235/85r17, but weren't available at price and load rating i wanted