Differential gear suggestion
 

Hi,
I just purchase a 2012 jeep JK sport and ordered a 3" trail master lift and installed some BFG all terrain KO2 285/75/17. My jeep is a automatic transmission and 3.21 gears and really found that i lost some bottom end and i expected that going from 265/70/17 to the 285/75/17. Would like to know if anyone here would have some advice on gearing selection it would be very much appreciated.

Regards,

Pierre Melanson

Re: Differential gear suggestion
 

3.21 is what they have been putting in the most recent jeeps, for the reason "don't ask". I had in my 89 xj and also my 03 tj 3.07 (std)
which suck. The first one I bot an scrap jeep removed the axles (3.73) and installed complete to the 89... Fire... then bot the 03 TJ
again it had the 3.07 had the gears changed to 4.10.. at the time was advised either for the same price 4.10 or 4.56 just maybe
later on I would like to go back to smaller tires then 4.56 rpm would be off the board so I went with 4.10 and haven't looked back.
3.21 to 4.10 or 4.56 remember they put 4.10 in the older Rubicon and it did great. I'd suggest 4.10 with tires up to and including
35's... if your going to use it for offroading only with 35's or larger or as a trailer queen then 4.56 is the way to go...Good Luck
and lets hear what you end up doing..

Re: Differential gear suggestion
 

Thanks Mr. White for the information.