Everyone needs to bookmark this one. It helped my installer (1st JK) get it right.

 

great write up. here is a jk rpm chart

 

thank you that was a great write up

 

I will be re-gearing this weekend, thanks for the awesome write-up!

View the Dana Gear and Pinion Tooth Pattern Interpretation document here.

 

Thanks for the addendum guys...I had been procrastinating for far too long making the additions and changes. I have amended the original posts to show jpop's gearing chart which is more appropriate for our JK's and added robl8's link for interpreting the mesh pattern per the Dana shop manual.
Thanks guys and good luck to everyone else.

 

Wow, really a great, informative post.

I have one question about regearing: Is it necessary to flash the computer for the new gears? I have a manual tranny so shift points are not a concern, I am just worried about speedo/odo and tach being correct.

 

I think there is an option on the superchips flashpaq to re-adjust your speedo/odo etc. for gear changes. If you dont already have one you should look into getting one, well worth the money. I think the AEV Procal might have an option to re-program for new gears as well, not positive though.

 

The superchip will allow a re-calibration of the gear ratio and the tire sizes. It is easy to use.

 

Yeah I have looked at this thread several times, thanks for the excellent write up the stealership told me 3.21s and I jacked up the rear wheels, and I did the mark and rotate tires, I came up with 3.73s. excellent write up. Everyone should read.................

 

A few things we found along the way doing a front rubicon upgrade to 4.88s.

At first, we thought the pinion was too deep because our first try with the stock shims was bound up. It turned out we needed to adjust the backlash and we were all set. Also, you need a 6 inch vise to hold the rubicon locker.

IMPORTANT NOTE ABOUT THE RUBICON LOCKERS! The sensor in the rubicon locker needs to be seated correctly. There is virtually no documentation that I could find and I learned the hard way on this one. Once I got everything together, the locker wouldn't release. It turned out that the sensor was pushing from the outside on the locker ring keeping it locked. As far as I can tell, and I've found no documentation to confirm, is that the mushroom end on the sensor rides inside the locker ring. Once the carrier is in, I couldn't find a way to get the sensor installed correctly without pulling the carrier out slightly, fully seating the sensor, and then reinstalling and torquing the carrier.