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Discussion Starter · #1 · (Edited)
A buddy of mine just got a 2011 Rubicon. He wants to put 40" tires on it. What size lift is required for that? TIA. He is going to do flat fenders, front and rear bumbers, winch, gears, super charger and what ever else he can think of. We just wanna be sure what size lift he needs for the 40"s.
 

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A buddy of mine just got a 2011 Rubicon. He wants to put 40" tires on it. What size lift is required for that? TIA.
Dude, I dont think your buddy is ready for 40s. There is alot of other stuff you need to do besides just a lift.

You can fit 40s with as little as 2.5" of lift if you have high clearance fenders and dont mind cutting.
 

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Discussion Starter · #3 · (Edited)
Dude, I dont think your buddy is ready for 40s. There is alot of other stuff you need to do besides just a lift.

You can fit 40s with as little as 2.5" of lift if you have high clearance fenders and dont mind cutting.
Let me rephrase that statement then. OP udated.
 

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With flat flares, a 1" body lift, and some fender well trimming, you can run most 40s on wheels with 3.5" or less backspacing, with 3.25" front and rear extended bumpstops.

As a result, with flat flares and a 1" body lift, any 3.5" or taller lift with all adjustable control arms, and front and rear trackbars will get you mostly there if you also run the 3.25" extended bumpstops.

With the flat flares, but without the 1" body lift, you would need 4.25" or more extended bumpstops. So, that would put you in the net 5" lift or more range.

I am running 40s on springs that gave me 3.125" with 0.5" coil spacers added, the rear axle stretched back 0.75", relocated rear frameside trackbar bracket, relocated rear swaybar, a 1" body lift, and flat flares on wheels with 3" net backspacing and much longer than stock steering stops.

Of course, this does not include any of the drivetrain and steering upgrades needed for 40s.

Here is where people typically must trim/cut the body:




Here is my build thread:

http://jkowners.com/forum/showthread.php?t=28802

Here it is in action:









And in the driveway:


 

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Discussion Starter · #5 ·
Thank you Planman. That is the info i'm looking for. I did forget to mention that his Jeep is an unlimited. I'm trying to convince him to stick with 35"s and the 4" teraflex full flex lift.
 

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40s are nice but to be honest a 4" teraflex with 35s is going to look funny IMO on an unlimited. I run 37s on a 6" and it's borderline and hence the reason i'll be upping it to 38s or 39s. if you get him settled on the 4" then he should go with 37s to 40s. but in the end it's what HE wants to do. :beer: 37s and larger were just made for the unlimiteds :D
 

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Thank you Planman. That is the info i'm looking for. I did forget to mention that his Jeep is an unlimited. I'm trying to convince him to stick with 35"s and the 4" teraflex full flex lift.
If he does a 2.5"-3" lift with 35s, he can skip:

rear upper and lower adjustable control arms
front upper adjustable control arms
driveshafts
hydro assist steering
chromoly axle shafts
rear swaybar relocation
welded in front axle sleeves
welded in front axle gussets
welded on front axle truss
welded on and custom cut rear frameside trackbar bracket
rear tire carrier beefy enough to hold a 135 lbs+ spare
flat flares
body lift
aftermarket and/or reinforced front and rear axle side trackbar brackets

It will handle better on the street and go 90%-99% of the places he wants to wheel.

Then with the $6,000-$7,000+ savings, he can buy a used TJ or YJ on 1 ton axles and 40" bias ply tires with an Atlas transfer case and full cage trail rig on Pirate4x4.com.

There would be even more savings if he was considering a long arm.

If I were to do it over again, that is what I would have done.

Like eMetal says, it depends on what he wants to do.

If he wants to beat the shit out of his daily driver by taking it places that still have some sort of challenge for a rig on 40s--or if he is building it for show--then he should build it on 40s.

If he wants a great daily driver and weekend wheeler but doesn't want to beat the shit out of it, then he would be better off spending the same money on a dedicated trail rig and build his Unlimited Rubi for 35s.
 

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Discussion Starter · #8 ·
40s are nice but to be honest a 4" teraflex with 35s is going to look funny IMO on an unlimited. I run 37s on a 6" and it's borderline and hence the reason i'll be upping it to 38s or 39s. if you get him settled on the 4" then he should go with 37s to 40s. but in the end it's what HE wants to do. :beer: 37s and larger were just made for the unlimiteds :D
Both of these Jeeps are on 4" teraflex full flex lifts with 35"s. IMO they both look fine and preform fine. 37" do look better if you have flat fenders. They look like shit with stock fenders.

 

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40s are nice but to be honest a 4" teraflex with 35s is going to look funny IMO on an unlimited. I run 37s on a 6" and it's borderline and hence the reason i'll be upping it to 38s or 39s. if you get him settled on the 4" then he should go with 37s to 40s. but in the end it's what HE wants to do. :beer: 37s and larger were just made for the unlimiteds :D
C'mon e! The 4" TF and 35's isn't bad! But, my 35's are for sale after all. :smokin:
 

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As already mentioned you can run 40's with not a lot of lift. I have about 5" of lift and 40's on rims with 4" BS, and they rub hard at the front with stock width axles. A little less backspacing would help some, but full width axles is the ultimate answer. Extending the steering stops stops the rubbing for the most part, but you lose a lot of turning radius.

Hydro assist is a big help and will be appreciated off-road.

Make sure the bumpers are small, I have a PJ stubby front bumper that required about 6" to be cut off each side.

C gussets and sleeves (or truss) make a lot of sense at the front. RCV shafts handle 40's well. Aftermarket rear shafts are a good idea too.

FWIW 37's and 4" of lift makes a lot more sense to me, and I don't think you lose much to 40's.
 

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I second PhilD's comments. We are running very similar setups; mine being a true settled 5.5" of lift. My wheel backspacing is 3.5". Minimal rubbing on frame, by 1/2" at most; no steering stop change at the moment. I have had to do no cutting in the front.

Very stable at Rubicon recently, with angles well into 40-50%.

I am not one who would go back to 37s though. 40s are awesome!!!!
 

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Running 40's takes a bit more planning. I just put 40's on my Unlimited..With only 3.5" of Rock Krawler lift. Besides all the obvious extra strengthening. You will have to revert to Hydro assist steering with in a year. Even sooner if you wheel it all the time.

Put it this way..So that you don't break it every time you wheel it if you have a heavy pedal....Expect to start at $8,000 in parts and labor. If he wants to drive it on the highway you can get away a lot cheaper..

Its a commitment. You either do it right or, expect shop time and more bill's..lol

Just my .02$
 

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Quite awesome. Was this pic taken on the Hell's Revenge trail in the "Escalator"? I've been there, just looked like it. Very Very neat Jeep you got there Sir. Thanks for sharing.
 

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A buddy of mine just got a 2011 Rubicon. He wants to put 40" tires on it. What size lift is required for that? TIA. He is going to do flat fenders, front and rear bumbers, winch, gears, super charger and what ever else he can think of. We just wanna be sure what size lift he needs for the 40"s.
Randy,
I run 40" Toyo mud terrains on my Unlimited - give me a call at 866-900-8841 and I'll talk you or your buddy through it. Let's make sure though that 40" tires are what he needs.
Cheers,
Bond
 

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OK, I haven't read every inch of this thread, but just a quick reply, 35's on a 4" kit is going to look like training wheels, we put 37's on the wifes JKU, with 5:13's, and when the time comes we're going to 39's or 40's
 

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new unlimited questions

I am new to jeeps and am looking to get a new unlimited. Wont be doing much 4 wheeling but want something that looks good and my 3 young kids will have fun cruising around town in. Should i be getting the 3.73 gears and the trac loc? i am really wanting to do 40's but it seems like a lot of people think the 37's are better as far as having much less mods to do? 4" lift clear both? I am fine with doing the poison spider fenders for clearance, i just don't want to be doing a ton of other major mods as again i probably won't be off road much other than fields and safe area with the kids. Again new to jeeps so anything helps. Thanks.
 

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I am new to jeeps and am looking to get a new unlimited. Wont be doing much 4 wheeling but want something that looks good and my 3 young kids will have fun cruising around town in. Should i be getting the 3.73 gears and the trac loc? i am really wanting to do 40's but it seems like a lot of people think the 37's are better as far as having much less mods to do? 4" lift clear both? I am fine with doing the poison spider fenders for clearance, i just don't want to be doing a ton of other major mods as again i probably won't be off road much other than fields and safe area with the kids. Again new to jeeps so anything helps. Thanks.
You answered your own question. Stick with 37s as 40s will require more stuff.

4" is more than enough lift but 3.73 gears isnt. I would definitely consider a numerically higher ratio.
 
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