Alright so i've never owned a 4 wheel drive vehicle but i was reading that the rubicons come with a 4.10 rear axle? My question is if you go to a bigger tire do you just have to change the rear gears? do the front ones really not matter since you primarily use rear wheel power for the most part? If someone could educate me on this it would be appreciated.

 

If you change one you would absolutley have to change both. (You would destroy things as soon as you shifted to 4WD) But you don't have to change gearing to go to bigger wheels. With the Rubicon gearing you can get by with 35's and no gear change at all.

 

You dont nessecarily have to change gears when putting bigger tires on, it all depends on how big of a tire you want to run and what gears you're already running. If you do re-gear you have to change both front and rear ring & pinions otherwise you wont be able to use 4 wheel drive and will have to remove your front driveshaft and/or remove ring and pinion from front housing and run an empty diff.

 

to explian it, simply think of a ten speed pedal bike, forget about steering for now and run a chain and a set of gears to the front wheel as well. now if you had the front wheel in a different gear from the rear the front would turn at a defferent rate causing.........well you can just imagine.

with that said your 4.10's is like an easier gear. can't get going fast no matter how hard you pedal but it sure is easy to get going and go up hills. which is what you want in a jeep

 

ok that's what i assumed but thought it was weird that the gearing options for the rubicons on the jeep website said a rear gear of 4:10.

 

ok so with that being said if i was to put say 35's on from my stock tires which i believe are 31's or 32's. what kind of gear ratio would i need to obtain something close to factory performance because my main concearn is loosing power to climb and what not. I'm not sure what gears are in my "x" right now but i'm sure it's probably the 3.73's. The chart on the other page shows 5.13's would be ideal but that seems a bit drastic for a 2 door.

 

the 2007 X model in Automatic came with 4.10s. 2008 and above X's in Auto are 3.73

 

well that's kind of disappointing? i wonder why they went from putting 4:10's to the 3.73's but thats what would be in mine then as it's an 09. What kind of gear would you guys recomend then?

 

5.13's are drastic depending on what you do. if all you do is wheel then go 5.13 if you hardly wheel 4.10 will be fine.


4.88's are idea, kind of the best of both worlds

 

Start with - Which transmission do you have?


There are seriously 1000's of posts asking this exact same question. The consensus for 35's is:

Auto - 5.13 (or 5.38 in a Rubi)
Manual - 4.88

Browsing through those 1000's of posts, you will notice that many people wish they had gone to deeper gears. I have only seen one that wished he had gone lighter. (and he was running a hemi...)


Open the FAQ's nailed to the top of this modified section. In the Drivetrain area you will find a good RPM chart. Plug some numbers in and see what you think. (remember to use the 'actual' tire height and not the mfg's spec!!)