Mall Crawler and 40s....

[Jeeperjamie]

Is it the weight or the larger circumference? I get differing answers. Like 35s vs 37s needing a re-gear, because of size not because 37s are 4lbs heavier than 35s per tire

35 to 37 isn't that huge of a jump based on weight but it's mainly the regearing needs to be done because of the ratio of the tire. But jumping to 40's is a whole other animal. You have to take into count weight on the axles and tire ratio. I've saw people burn a transmission up in a JK running 40's without being properly geared.

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[PyrPatriot]

Made 2 days in mine. Bought it on a Monday, ordered tires Tuesday, had them installed Wednesday. 2.5" lift went on that Friday. I did make it 4 months before adding a bumper and winch.

Said I was going to keep it stock other than tires, that was a lie

bumper, winch, and 35s went on at 6 months after I got tired scraping belly on muddy/silt trails and seeing my friend in their 4Runner get stuck in mud all the time

 

[Alabama Mud Machine]

Is it the weight or the larger circumference? I get differing answers. Like 35s vs 37s needing a re-gear, because of size not because 37s are 4lbs heavier than 35s per tire

Not all 37's are only 4 lbs per tire heavier than 35's... Every brand and model tire is going to be different. Most 37's are noticeably heavier than 35's.

But yes, a lot of it has to do with weight, but also stress from the overall bigger tires puts on the axle and steering components from the added pressure it takes to push the tires around.

 

[J.Noack]

You can run 40's... Just saying that there are some things I'd beef up before attempting to offroad with 40's on the stock axles, like the knuckles and order some axle shafts that delete the FAD unit, and some other stuff, like HD ball joints.

Agreed.....
I’m 5000 miles in rolling 40’s with no issue cruising around, 80mph hwy, etc....with zero negative effect on anything.....yet.

But.....there always a but lol.....Even after 5.13 gearing, I’m awaiting the arrival of some RCV axles, which will get the job done more or less (deletes FAD and insanely stronger than Stock axles.)
Even after that, I’ve broken enough shit over the years to realize that the D44’s will certainly eventually fail on the trails with 40’s.
I’ve learned that It’s just to easy to yank the 40’s off for wheeling to use 37’s. Beat the snot out of it, wash’er up, slap the 40’s back on for around town.

Hell, I had 2.5 ton Rockwell’s on a rock bouncer for several years while on 43 stickies. Broke those shafts several times and finally had to do the Ouversons conversion to 2” shafts. No more breaky breaky, ...never...ever.

Point being: Alabama Mud Machine is 100% spot on. With what you currently have (my shit included) is on somewhat of a borrowed time situation running 40’s on D44’s, even with upgrades. That rotational mass equation is never forgiving!

But....the irresponsibleness in me forgoes logical reasoning because the look and feel of the 40’s is so satisfying. I hereby declare that I will continue to roll the absolute dog shit out of them lol!

 

[PyrPatriot]

Not all 37's are only 4 lbs per tire heavier than 35's... Every brand and model tire is going to be different. Most 37's are noticeably heavier than 35's.

But yes, a lot of it has to do with weight, but also stress from the overall bigger tires puts on the axle and steering components from the added pressure it takes to push the tires around.

Well crap, hope I'm not just needlessly wearing parts with 80lb Falken MT 35s...

 

[Alabama Mud Machine]

Well crap, hope I'm not just needlessly wearing parts with 80lb Falken MT 35s...

My 37x13.50r20 Kumho KL71's are only 83 lbs. each... Those Falkens are HEAVY tires. The stock 285/70r17 Falken WP M/T's that came on my JTR were 63.3 lbs. each. That's ridiculous.

 

[SloW8]

I know a guy that runs a 6" Evo Lift and 40s on stock axles. Ill ask him how its going. He must have gotten one of the first kits as he was one of the first Gladiators in the state.

 

[PyrPatriot]

My 37x13.50r20 Kumho KL71's are only 83 lbs. each... Those Falkens are HEAVY tires. The stock 285/70r17 Falken WP M/T's that came on my JTR were 63.3 lbs. each. That's ridiculous.

Yah, and I have yet to hear from anyone (including the Jeep/offorad shop I got them from) puncture or slice one yet. they are heavy, but they are thicker E-rated tires too. Odd that they throw chunks and chip on rocks though. It's just a shame that I'm going to get near the same wear on components from 35s when I could get (and fit) 37s

 

[Mopar King]

Ok...I guess I'll just do 38s and live with it...thanx guys

If your running 37s you think you'll notice a change to 38s? I wouldnt....thats 2k down the toilet unless your 37s are bald already.

 

[Jeeperjamie]

If your running 37s you think you'll notice a change to 38s? I wouldnt....thats 2k down the toilet unless your 37s are bald already.

Totally agree with this, one of the reasons I'm waiting until my 35's wear out before I move to 37's

 

[pmontague1968]

If your running 37s you think you'll notice a change to 38s? I wouldnt....thats 2k down the toilet unless your 37s are bald already.

I probably have 10k miles left...just planning ahead...

 

[Alabama Mud Machine]

Yah, and I have yet to hear from anyone (including the Jeep/offorad shop I got them from) puncture or slice one yet. they are heavy, but they are thicker E-rated tires too. Odd that they throw chunks and chip on rocks though. It's just a shame that I'm going to get near the same wear on components from 35s when I could get (and fit) 37s

My 37’s are E-rated, as well.

 

[Lynn_F]

I'm a mall crawler...I'm one of those weirdos, I guess, that loves jeeps because they're awesome convertibles not for their off-road prowess. I know to most of you that makes me a poseur...despite that, what are your thoughts on putting 40s on a mall crawler...max tow axles...no, I don't plan on putting 60s or really anything...I've heard both sides...if i'm not doing ANY off-road can I put 40s on my JT? I'm running 37s now on 4.5" lift, AAL hi-line fenders setup...I will regear 4.88 or 5.13....thanks!

Oh, and if you're wondering why? Aesthetics...I just don't think the JT looks right without 40s...not sure why, everytime I look at my 37s I think...damn I wish I went 40s...

This is a good thread. I'm sure that ball joints and knuckles are probably necessary upgrades but if you are like me and truly will not do any offloading then I'm sure that will be sufficient. The main issue I had running 40's on my JK was keeping the tires balanced. Once they start chopping the tread and bouncing at speed - that is when the bigger trouble starts. If you stay on top of rotating and balancing them, you should be able to run them.

 

[pmontague1968]

This is a good thread. I'm sure that ball joints and knuckles are probably necessary upgrades but if you are like me and truly will not do any offloading then I'm sure that will be sufficient. The main issue I had running 40's on my JK was keeping the tires balanced. Once they start chopping the tread and bouncing at speed - that is when the bigger trouble starts. If you stay on top of rotating and balancing them, you should be able to run them.

Any recommendations on those upgrades for the JT (knuckles and joints)? Thanx

 

[Lynn_F]

Did a quick search for knuckles and couldn't find anything...I'm sure your local offroad shop could point you in the right direction. These Synergy ball joints have a pretty good reputation and are what I used on my JK. They are noticeably beefier than stock. They aren't real expensive but it is a good half day job to replace them yourself if you haven't ever done it before.

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