I would like to get feedbak on all of you experts out there. I am planning on installing 40" tires with about 5.5" lift on my JKX. Besides upgrading/reinforcing the axles and steering. What gears would work best? What trimming needs to be done? Any suggestions on tires? Any other feedback or recommendations?

Pictures of JKs on 40s are appreciated.

 

If you are putting a new 5.5 lift on..you'll need new driveshafts...

 

I read where a guy had to cut the corners off the bar that is located on the front of the frame. It's the little bar on the front of the frame that hangs down and that plastic air dam connected to. Something about with the tires turned all the way and suspension compressed the tires would hit there. You'ld have to check it out.

Also you know about the pinch seam and frame slider right?

I also think you would have to do something about the stock fender flairs, I rub with 4" and 35", not bad but I did touch the stock flair in full stuff

 

A lot of stuff is going to depend on what you have now, and what you want to do with it later, once you have those 40's. Do you have a manual or auto transmission? Is it a 2-door or a 4-door? Do you have stock fenders or flat fenders? Are you wanting it to just be on the road, or will you take it wheeling - rocks, mud, etc.?


Here are a couple of good threads to read to get a lot of the information that you'll need:

https://www.jk-forum.com/forums/show...uspension-lift.

https://www.jk-forum.com/forums/show...mp-flat-flares

Good luck! And make sure you post some pics when you're finished!

 

You need to pm Planman.

 

Thank you for the help. Yes, it is a 2 door JK X. I am changing my fenders to Smittybilt XRC front and rear body armor. I will be doing light trailing and some mudding since thats all you can really do in Florida. I am affraid of rock crawling with a weak D30 on 40s.

I was not aware of the 1" body lift needed. I am guessing a transmission cooler would help since I have an auto transmission.

Also, anyone running 40s with 4:88 gears? Or are 5:13s the least you can use with these size tires? Do 5:13 gears fit in a D30?

 

Wait you're gonna put 40s on a d30? Thats asking for trouble. You should try and find a rubicon take off d44, at the least.

And yes, 5:13s will fit in a d30.

 

Rubicon d44 use the same housing a d30's. If he gussets, trusses, uses the rse external sleeves, he should be okay carrying a spare shaft or two.

A d44 won't hold up to 40's with aggressive wheelspin in the mud anyway. If he's gonna upgrade he'd best use a d60.

 

Yeah. My front axle is a D30. So do I have any other options besides light trailing only until I can upgrade (no mudding). Or upgrade to front D44 and perhaps a rear D60?

 

Will gusseted, sleeved and re-sealed D44 with 5:13 hold up ok? For medium duty offroading?