Rear axle longevity (carnage pics)

[Tr4ckD4ys]

So you’re buying an 80.000$ vehicle only to have to put another 25.000$ not i clueing all the other stuff typically done to it. So let’s say 115.000$ vehicle for ultimate off-road capability. For that money, is it truly ultimate off-road capable? Are there other cheaper options to get to that level of capability? This is purely hypothetical and probably pointless anyway… who doesn’t love badass vehicles.

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[J0E]

Nothing exciting when it failed, just snow wheeling in 4wd. Locker started clicking and not wanting to engage. Sounded like I had a baseball card in my spokes, but louder. But no noise when driving without locker.

Low traction, my guess is the damage was done previously in a high traction environment.

Its the leverage of the 37s and the torque. The same reason they didn't put the 4 to 1 in the 392.

Exactly

TQ * 1st gear * t-case * differential

470 * 4.71 * 2.72 * 3.73 = 22,459

260 * 5.13 * 4 * 4.88 = 26,035

The 3.6L Rubicon with manual trans and 4.88 gearing has more rear wheel torque in 4-low than the 392 (unless optioned with the Xtreme Recon).

Now do the 2.0L turbo with automatic and the 250% increase in torque by the torque converter:

295 * 4.71 * 4.0 * 4.1 * 2.5 = 56,967

Most folks confuse HP with T. It's exceeding torque designs that break components. Put a 750 HP 168 cu. in. Offenhauser engine in a JLR and you're less likely to break drivetrain components. Gears make torque, that's why a small electric winch can pull 12K.

That’s not the only/main reason for the 2.72 Tcase ratio. Do you have a 392? Or even driven one in low range?

What is the reason then? They needed to reduce torque, that's an easy way to do it. My 66 Chevy stepside 4x4 with a 400 HP 400 cu in, IIRC weighed less than 4,000 lbs.

I like to crawl, and an automatic + 4:1 xfer case lets me crawl.

I always think about how Ford put a Dana 50 in the Bronco Raptor, which comes with 37s. They don't put more expensive axles in for fun, it's because the Dana 44 can't handle 37s. Jeepers who offroad on 37s with stock axles are living on borrowed time.

My guess is that's why Jeep doesn't offer 37's from the factory, they don't want to go to a Dana 50 or 60.

Jeepers who offroad on 37s with stock axles are living on borrowed time.

Or more accurately, exceeding torque design limitations.

I said nothing of factory reliability. I’m Talking about axle longevity for those who actually wheel and modify their vehicles. This thread probably isn’t for you…

When did I ever blame jeep? This thread isn’t for you either obviously. Or are you going to delete this post soon like you did your other recent reply earlier??

In further proof of no blame towards Jeep, it’s not at the dealer for repairs, not going to ask either.

I guess you're the one who decides who this thread if for. Silly me, I thought it was for members of the forum.

 

[1996cc]

Instead of “lockers before light bars,” my new motto is “Tons before tires”

 

[azwjowner]

The most interesting part of this to me is that the upgraded chromoly axles twisted. I would have thought they would hold up, but I guess a Dana 60 is necessary even in that respect too.

 

[Zandcwhite]

Could always go for the fusion 40 spline semi float 60 and keep your wheels and save $19k...

 

[1996cc]

Im

Could always go for the fusion 40 spline semi float 60 and keep your wheels and save $19k...

I’m already having to cry twice, I don’t want to cry 3 times. I’m considering skipping the 14 bolt and going straight to an 80 rear!?!

 

[azwjowner]

BTW, I don't think it's a 392 problem so much as a 37" tire problem.

@wibornz has reported repeatedly destroying his axle on 37s, including having multiple lockers self-destruct: https://www.jlwranglerforums.com/fo...ratio-would-you-reccomend.102453/post-2125052

 

[AcesandEights]

This is about conditions and driving style, not what engine you have.

The torque difference between the 392 and 3.6L isn't significant at the rear wheels, and when multiplied by the t-case, is greater in the 3.6L Rubicon with manual trans.

 

[1996cc]

Too much of this conversation is just assumptions and guessing (and we all know math doesn’t translate to real life). I’m just trying to pass on my real world experience to increase the overall knowledge base. So many threads drone on and on with web wheeling. This happened while actually wheeling and I shared it. Take it for what it’s worth and move on - better yet, get out and wheel yourself and show us how you’re pushing the limits!

 

[dragoneggs]

I sold a 3.6 JL and wheel hard two 2.0 JLs. Just bought a 392 and the torque is insane. I appreciate OP sharing his experience. Mine is a Pavement Princess until I decide to lift and upgrade to tons.

Love that purple… look forward to your build!

 

[gsbrockman]

I’m already having to cry twice, I don’t want to cry 3 times. I’m considering skipping the 14 bolt and going straight to an 80 rear!?!

May as well go with a 10.5” front axle and a 12.0” banjo style rear axle like I have in my 2022 RAM 5500

 

[19 JLUR Bright Whit3]

hehe. You said banjo.

 

[Jeep Dude]

My guess is that's why Jeep doesn't offer 37's from the factory, they don't want to go to a Dana 50 or 60.

My guess is that 37's would slow down the 0-60mph times .

 

[thecritter]

Much technical info on here. Slow rolling on Chrystal Beach = tickets, even if no one is around. Pay to play I guess. Jump it need better shocks, wheel it... bigger tires. I wish everything was made bullet proof, but would make for a boring weekend fix. From factory without mods should work without any question. Any JL should work fine with any tire you can fit without modifying. OP sorry for your loss of axles.

 

[MSparks909]

Im


I’m already having to cry twice, I don’t want to cry 3 times. I’m considering skipping the 14 bolt and going straight to an 80 rear!?!

Only reason I didn’t go 14B or 80 rear is I didn’t want to mess with air lockers. That’s the only option for those axles. I wheel my e-locker Dynatrac XD60s with 5.38s pretty hard. I’m not rock bouncing every obstacle but I’m wheeling it harder than anyone else I’ve *personally* seen wheel their 392. If it grenades I’ll be the first to post about it but I’ve been pretty happy with them so far. I’m on 40” STT Pros FWIW.

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