hey guys... i just recently bought a new 09 jk 2-door x and it comes with 3:21 gear ratio and i was womdering if i can try to get some pointers on what i need to do to get it to par on 35's. a person suggested gears must be adjusted to 4:56 and i was seeing if i could get some more input. i want to get the 5in long arm rubicon express supension lift and 35 MTRS so what ever best for that set up would be helpful.

 

everyone that i have run into says a min of 4:88's if your going to go bigger than do 5:13's also depends of stick or auto. search the forum there are TONS and TONS of posts on gears here

Also welcome to the forum and congrats on the jeep

 

Browse through the FAQ when you get a chance. Lots of good info in there.

https://www.jk-forum.com/forums/modified-jk-tech-2/modified-tech-faq-answers-questions-every-newbie-has-18617/

As noted above, what ratio you go to depends on transmission type and personal preference. Generally, 4.56 or 4.88 for a manual. 4.88 or 5.13 for an auto. (personally, if I had a Rubi front axle I'd go 5.38's with my auto)

5 inches is a lot of lift, do you have plans to go up to 37's? Factor that in to your gear choice also.

Also, I believe there is a difference in carriers between the 3.21's you have and the 3.73 and up gears. So look in to replacing those.

The only other suggestion is, since you have a D30 up front and are going to 35" tires, do a search and look at all of the axle upgrades people are doing. Try and fit some into your budget. Chromo shafts, tubes, C gussets, truss, etc.

 

Go 5.13's with the Dana 30 front axle. ( I wish I had 5.13's)

A 5" lift sounds a little much for 35" tires; a 2.5- 4" lift would be better for 35"s

 

I plan on going to 5.13 but I have an Auto. I currently have 4.10 so it is not something I have to do right away.

What do you have stick or auto?

 

I went with 5.13s on and auto and thought it was gonna be extreme before I put them in. I almost got cold feet on te eve of the gear change.

Now, I would consider 5.38 if I didn't think the pinion was too small. I'm spinnin at 2400 @70 mph on the fwy. Perfect. If I had done 4.88s I might have been dissapointed.

 

I on the other hand had 4.10s and I was only able to bear the 35s with them for a week. They spun the 33s ok but the 35s were just too much. I have 5.13s and wouldn't mind if I had got 5.38s. Do yourself a favor and gear lower than you think (numerically higher).

 

well i am still a bit confused... i had a 98 tj with a 4inch skyjacker kit and 4:10 gears and i was trying to get a 5 inch because of the bad flooding in my neighborhood... every other time it rains it floods hence why my brother drives a lifited truck and mother a suburban... but i dont mind the 4 inch but the 5 was just cause i wanted to but i jsut wanted to be real specfic as far as gears go cause i ran my tj so hard my drive shaft broke...

 

You can't really compare the amount of lift needed to fit 35's on a TJ with the lift needed on a JK. A 2" lift will fit 35's. Or trim the fenders and you can run them with no lift. So a 5" lift will leave a whole lot of empty space. Anyway, it's just a heads-up so you aren't surprised with the results.

Check this post in the for sale section, and note the reason he is selling the tires...
https://www.jk-forum.com/forums/jk-wheels-tires-113/5-mickey-thompson-baja-claw-35-a-83190/

If you go to a 4 or 5 inch lift, you'll be getting new driveshafts anyway.

With an X, you have a Dana30 front axle. It's small. The gears are tiny compared to the D44 gears in the rubicons. That is the reason some folks choose 4.88's instead of 5.13's, for that added bit of strength. Just another item to keep in mind.