EagleArmsHBAR

and talked to them about switching the ratio from 3.21 to 4.10 so it might handle better with Rubicon tires/wheels (if I can find a nice person to sell me some). They freaked out and told me that I would void the warranty even if they do the work. They also told me a 3.21 rear differential does not exist (as I am looking at my spec sheet) and said that it would cost about $3000 to do the swap.

So...how bad will my Jeep X drive with the 3.21 and Rubicon 17" Moabs with mud tires?

James76

So my x that came with 4.10's has no warranty? makes no sense. Id find another dealer or a small reputable shop to do the work. Swapping in a gear ratio that was a standard option on a previous model of the same exact vehicle. Doing that will decrease the load on the engine so i see no problem. Definitely find a new dealer!

EagleArmsHBAR

Yeah, screw them! Anyways, do I really even need to do the swap just by putting the Rubicon wheels/tires on it?

greenamphibious

your dealer is a window licker

James76

i have 4.10's with 33's and i cant imagine having any less power. I say take it for a spin, while keeping your originals on hand. Try merging on the highway, and if it doesnt feel safe or adequate definitely upgrade. I wouldnt even mind having 5.13's for even more pep. I do more city driving than highway.

redroc_jk

I have a stock X with 17 inch wheels and 265/85 tires with the 3.21 gear ratio.
I have a 6 speed and no problems with lack of power.

riverzendz

It's doubtful that you'll notice a difference in going from street tires to the Rubi M/T's.

JK-KJ

transmission has alot to do with it...6-speed and you'll be just fine, auto and you may not like it

i have 3.21 with 33's and 6-speed and it's fine

britjk

I've got an automatic with 4:10 gears. Kept the 18" Sahara wheels and went with 305/65/18"BFG All Terrain KO's. They measure to be 33.8" or (34's). Got plenty of Power.

MMO blk JK

You're good! I have 3.21s and rubi wheels and tires and it runs just fine. definite lose of power compared the 16" steel wheel and the tires the come with (225/xx) but no worries you won't have any regrets