Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: rolandjc on February 27, 2010, 03:16:41 PM

Title: speedo is out 20km hr
Post by: rolandjc on February 27, 2010, 03:16:41 PM

hi guys please bare with me as i am new to owning a jeep and i may get some things wrong.
when i bought this J and brought it home i noticed that my speedo was out about 20km. so i think the gearing has been changed to be out this far. my question is on a jeep how can this be corrected. thanks for your help in advance
rolandjc

Title: Re: speedo is out 20km hr
Post by: apex on February 27, 2010, 03:37:52 PM

speedo gear is an easy swap. It's on the t-case and pretty straight forward.

Does it have larger than stock tires?

Title: Re: speedo is out 20km hr
Post by: rolandjc on February 27, 2010, 03:57:08 PM

on the door it suppose to have 205's but it has 215s on it

Title: Re: speedo is out 20km hr
Post by: apex on February 27, 2010, 04:50:18 PM

http://www.gotjeep.net/speedo.html
http://www.jeeptech.com/javaAps/Speedo.html

you'll need to know your gears as well.
http://www.getahelmet.com/jeeps/tech/findratio/

Title: Re: speedo is out 20km hr
Post by: Tagg on February 27, 2010, 09:56:13 PM

depending on the year of the jeep an AEV Procal module can adjust it to dead on.
It took me a couple of tries but mine is now exactly on my gps reading

Title: Re: speedo is out 20km hr
Post by: Evil-Jeep on March 04, 2010, 12:06:48 AM

As a general rule of thumb for every 10% increase in tire size your speedo should read 10% slower..... for every 10% increase in gear ratio your speedo should read 10% faster. it is however a rather inexpensive and easy fix.