Stock Rubi axles with 40s—OK for hard wheeling or no?

[chrisandrews]

Question about wheeling 40s with stock Rubi axles:

I do a fair amount of rock crawling (as opposed to overlanding or mud-bogging). My last rig was a 2020 JLUR (2L) on 37s and never had even a hint of an issue.

I’ve got a 2022 JTRD coming to me in just over a week. I’ve ordered a Fabtech 5” short-arm kit, heavy-duty front drive shaft, and 40” Cooper STT Pros on Black Rhino wheels.

Thoughts on the new setup? Am I risking axle catastrophe?

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[Dougstdig]

Yes

 

[AXISJT]

yes 37/38s are about the safty limit on the JTs there's a few users on here that have already had to replace axles on 40s

 

[chrisandrews]

Hmm. Now rethinking this build! Talked with some wheeling buddies after I posted, and they also think it’s pretty iffy with 40s. Not keen to spend so much more for an axle swap, so might just lower my sights and stick with the setup I know that works—37s and 4” lift. Sadly the drive shaft is already on its way, but that just means I’ll have it when I’m ready! Or maybe I’ll throw it on there anyway, if it’s not *too* long for the lesser lift.

 

[trailless]

I'm going with 37s and a 4.5" lift. The only way I'm going 40s is when I upgrade my axles. If I get decide to get new axles, I'll sell upgrade to 40s. Then I'll sell my old ones.

 

[Renegade]

No, and these aren’t even 40s…

 

[j.o.y.ride]

Hard wheeling is very subjective. Does hard mean hammering up everything you see, or does hard mean the obstacles are challenging but you pick lines and go slow with steady throttle? You could be okay on 40s if you're taking it easy but if you want to hammer on it you will break.

At a minimum the knuckles, shafts, ball joints, drag link, and tie rod should be upgraded... and a truss is welcomed.

 

[rharr]

how did you blow the ball joints out of the C

 

[Larry D]

No, and these aren’t even 40s…

Well that's not good

 

[chrisandrews]

Very good points. I actually do challenging stuff but definitely take my time and pick the lines well. But I’m going to save myself the trouble and cancel the 5” kit and 40s. I can always upgrade someday.

Hard wheeling is very subjective. Does hard mean hammering up everything you see, or does hard mean the obstacles are challenging but you pick lines and go slow with steady throttle? You could be okay on 40s if you're taking it easy but if you want to hammer on it you will break.

At a minimum the knuckles, shafts, ball joints, drag link, and tie rod should be upgraded... and a truss is welcomed.

 

[Rusty PW]

That was a HELL of a bounce.

 

[u-joint]

No, and these aren’t even 40s…

Is there a thread with a backstory here?!

 

[j.o.y.ride]

No, and these aren’t even 40s…

Looks like he was using a rock and a log to try and get up a ledge that was too tall for him, and things went badly. Possible 40s would have helped clear it. Hard to say.

 

[Renegade]

Looks like he was using a rock and a log to try and get up a ledge that was too tall for him, and things went badly. Possible 40s would have helped clear it. Hard to say.

The front made it up that ledge without problem. I wasn’t able to get the rear up without risking damage, so started trying to work myself out. I managed to get the back end over in front of a tree, kept trying to get myself out, and popped the u-joint. Instead of being (half) smart, and getting winched at that point, I continued to try to drive out of my predicament. The turning inner shaft forced against the stationary stub shaft, and the ball joints popped out. I slid that log under the axle after the fact as insurance in case the jack didn’t stay put. I ordered up a ball joint press and put it back together and drove out. I definitely learned from my mistakes that day. I had done that climb several times previously, but the traction was low that day.

The 2nd two photos were a different day. There was a bounce that day, but it really wasn’t that bad. I think I had ejected a u-joint clip prior to that, and the joint walked and broke. The twisted splines are from the rear. I wouldn’t have known about those had I not upgraded to chromoly shafts.

 

[Mojave40]

I won't say there isn't risk because there is always risk but these 3rd generation Dana 44's are much beefier than the gen 1 and 2 in older jeeps. I ran 37's on my 2016 JK for years running very difficult trails and never had an axle problem on the gen 2 44's. Now with my Gladiator Mojave I'm on 40" STT Pro's with the stock m210/m220 axle and feel confident in them. I'm in SoCal and certainly take a rock crawl approach. I'm not a rock bouncer or skinny pedal wheeler. Its early as I've only ran 2 difficult trails but no issues yet.

I know my answer isn't the popular opinion but your getting the answer from a guy who wheels with 40's and stock 44 axles. I would never talk someone out of going with stronger / bigger axles but I want to impart real world testing knowledge.

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