Rear axle longevity (carnage pics)

[1996cc]

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 it so far. I’m on 40” STT Pros FWIW.

We could definitely be friends I don’t mind the air option, so we can compare notes, when I get to that stage. ?

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[MSparks909]

We could definitely be friends I don’t mind the air option, so we can compare notes, when I get to that stage. ?

Feel free to shoot me a DM here or a message on IG anytime! Happy to help. If you don’t mind air lockers then I’d definitely consider a shaved 14 bolt with the 40 spline axle upgrade from Fusion. You’d have to try hard to break that one. If I break this 60 I’m most likely going to jump up to that or just say screw it and go to fabricated 10” axles. I’d skip the 80 just because it’s so damn heavy and hangs low. It is a tank though. I’ve drug my 60 quite a few times, I’d definitely get hung up more if I had an 80.

 

[Dyolfknip74]

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!

While I may not own a 392, I would have to say math directly translates to real life. Lol. Some would say it's literally the basis of life.
Out of how many 392s sold have had this happen? I have to assume you're not the only one not "web wheeling". You were using the vehicle outside of parameters designed by the vehicle designers and had a failure. Said failure also came after you self admitted to doing donuts repeatedly in either 2wd or 4wd?

While I'm sure we all appreciate your "real world experience", methinks your idea of wheeling and my idea of wheeling are 2 seperate entities.

I will say kudos to your attitude though. There are a lot who would be beating their chest about this being a warranty issue when it's clearly not for various reasons. Get some 60s and beat on it like a red headed stepchild.

 

[Retrograde]

In case anyone is wondering how the Dana 44s will hold up long term with our amazing motors, here is my experience... And the upgraded Dana Spicer chromoly shafts don’t like the power either ?

I wish I knew what to tell ya... but all the guys I knew back in the day who narrowed Ford 9" axles are retired (or dead).

 

[Jeep Dude]

Go to any dragster forum, Camaro forum, Mustang, Porsche, etc, and search out most of the "My Rear End Blew" threads. There is one common enemy in virtually all of them, the death knell of it all.

WHEEL HOP

 

[JeepinJason33]

My neighbor has his and hers 392's. He is going to put the Currie 70's under his. Hers is just for around town... I wheel with him nearly every weekend and they have yet to make it over an obstacle that my nearly identical MC suspension JLUR can't make it over. He also has coilovers.

The 392 was not available when I purchased my JLUR and now my hesitation around the switch to the 392 is that I have well over 30k of suspension, wheels, tires, bumpers, armor, etc. on my JLUR. I believe I paid around 62k for my Rubicon. So, I am at 90-95k for my setup and with 37's, I should be OK with the Dana 44's as long as I am smart with the throttle off road and don't get hopping on the tough stuff. I run the toughest trails all over the country without a problem. With 37's I can also flat tow it behind my motorhome without too much of a problem.

The 392 with similar options is 85k. So 23k for the engine upgrade. Add another 30k to upgrade the suspension, tires bumpers, etc. and now you are at 115-120k. Running the same trails as I run, you maybe more likely to break the axle with all of that torque. So, you upgrade axles which is another 25-30k and you now have a 150k into the vehicle. Other than having the ability to run bigger tires, there is not that much of a performance issue off-road over the JL I already have. Sure it is much more powerful on road and in the sand. However, you have spent 50k without much more benefit off-road. Your gas and probably long term maintenance will be more. The 392 is not known for it longevity. For 150k you could have a heck of a buggy that could crawl any trail in the country.

It is funny how some 392 owners throw out "do you own one" like these are untouchable and the only reason people don't have them is because they can't afford one. I have owned two SRT's and a Trackhawk. For the money, the Trackhawk was just not worth it and this is coming from a lifelong Jeep guy that has owned 34 different Jeeps in the last 40 years. Other than the drivetrain and a few tweaks on the brakes/suspension, it was still a $100k Jeep. For the money, Jeep just can't pull off the high end combo of price/value. I stopped trying to get my speed fix from Jeep and purchased a M5 that gives me speed when I want it on a vehicle that is designed for speed and the Wrangler takes me off-road just fine.

 

[AcesandEights]

I think folks that throw that out, have you driven one, don't understand what they're talking about. A 392 is an engine that gives you more power in two wheel drive. So what. I didn't, and most people didn't, buy their Jeep for two wheel drive. The 392 in two wheel drive has a third of the torque of four wheel drive, and it's still a Jeep. So what. It's like saying, have you ever gone pheasant hunting with a .45-70. Well then you wouldn't understand. Ever play football with a patio paver? Uh, ok. People have been breaking diffs and twisting shafts since the beginning of time. Bragging that you void warranties is like bragging about how many crayons you can eat.

Cool story bro.

 

[1996cc]

To be clear, my statements about owning one were directed at knowing why transfer case gear ratios were chosen, etc. People make blanket statements about gearing because of what worked in their rock crawling 98 TJ With a straight 6 or possibly an LS conversion.

I agree with most of your comments Jason. And yes, everywhere I’ve gone in Moab, etc with it, I’ve also gone in my old 3.6 motors. HOWEVER, this is a hell of a lot more fun during the process! Those dirt/sand sections between the rocks in Moab where you used to fill the time talking on the radio with your buddies or arguing with your wife/kids, I’m mashing the throttle and laughing or smiling the whole time. Snow is about the same performance as my prior motors, just worse fuel economy (but as everyone keeps pointing out the reasons people do or don’t buy jeeps, no one buys them for fuel economy). Daily driving is more fun, I smile every time I start the Jeep - that never happened with prior jeeps. And finally, I live an hour from some great sand dunes, where there is no comparison - this thing is absolutely amazing in the dunes! I’ll let this video speak for itself, it’s like having a street legal side by side.

Jason - another motivator for me to end up with this is that I was able to take EVERYTHING from my 19 JL (all my current mods), down to pulling the hydro bumps and drivelines and put it into my 392. That made the math work out to less than a motor swap would have cost in my old one.


Aces, others have talked about 2wd way more than I have in this thread. I could really care less about street driving. The main reason I keep it in 2wd all the time is I have an Ultimate Dana 44 front axle with regular Ujoints. Not something I want under power all the time. And there are always haters- someone asked me about warranties (I didn’t bring it up to brag), and I said I voided it (ie. 37”s, regearing, trussing the axle, aftermarket shafts, etc…). If I would have complained about the dealer not covering it, would you have hated on me for that too? Looks like you’re only 2-3 hours south of me, if you want to meet up in Florence, I’d be glad to give you a ride in the dunes. It might change your mind, or at least let you experience how fun and capable these things are. My friends that have similar backgrounds to all of you: fast cars, wheeling for years, etc. are all a bit mind-blown after riding in or driving this. If I would have known how much fun it would be, I would have had a conversion done years ago.

 

[beast40]

To be clear, my statements about owning one were directed at knowing why transfer case gear ratios were chosen, etc. People make blanket statements about gearing because of what worked in their rock crawling 98 TJ With a straight 6 or possibly an LS conversion.

You're such an ass lol.

There is nothing magical about the 392. (yes its the best factory Jeep ever made)
A drive train is a drive train.

 

[J0E]

Go to any dragster forum, Camaro forum, Mustang, Porsche, etc, and search out most of the "My Rear End Blew" threads. There is one common enemy in virtually all of them, the death knell of it all.

WHEEL HOP

Exactly, and wheel hops dirty cousin, bounce from bumping it, does the same thing.

My neighbor has his and hers 392's. He is going to put the Currie 70's under his. Hers is just for around town... I wheel with him nearly every weekend and they have yet to make it over an obstacle that my nearly identical MC suspension JLUR can't make it over. He also has coilovers.

The 392 was not available when I purchased my JLUR and now my hesitation around the switch to the 392 is that I have well over 30k of suspension, wheels, tires, bumpers, armor, etc. on my JLUR. I believe I paid around 62k for my Rubicon. So, I am at 90-95k for my setup and with 37's, I should be OK with the Dana 44's as long as I am smart with the throttle off road and don't get hopping on the tough stuff. I run the toughest trails all over the country without a problem. With 37's I can also flat tow it behind my motorhome without too much of a problem.

The 392 with similar options is 85k. So 23k for the engine upgrade. Add another 30k to upgrade the suspension, tires bumpers, etc. and now you are at 115-120k. Running the same trails as I run, you maybe more likely to break the axle with all of that torque. So, you upgrade axles which is another 25-30k and you now have a 150k into the vehicle. Other than having the ability to run bigger tires, there is not that much of a performance issue off-road over the JL I already have. Sure it is much more powerful on road and in the sand. However, you have spent 50k without much more benefit off-road. Your gas and probably long term maintenance will be more. The 392 is not known for it longevity. For 150k you could have a heck of a buggy that could crawl any trail in the country.

It is funny how some 392 owners throw out "do you own one" like these are untouchable and the only reason people don't have them is because they can't afford one. I have owned two SRT's and a Trackhawk. For the money, the Trackhawk was just not worth it and this is coming from a lifelong Jeep guy that has owned 34 different Jeeps in the last 40 years. Other than the drivetrain and a few tweaks on the brakes/suspension, it was still a $100k Jeep. For the money, Jeep just can't pull off the high end combo of price/value. I stopped trying to get my speed fix from Jeep and purchased a M5 that gives me speed when I want it on a vehicle that is designed for speed and the Wrangler takes me off-road just fine.

The 392 with similar options is 85k. So 23k for the engine upgrade. Add another 30k to upgrade the suspension, tires bumpers, etc. and now you are at 115-120k. Running the same trails as I run, you maybe more likely to break the axle with all of that torque.

Gears make the high torque, not the engine. The 470 ft-lbs isn't breaking anything. As @AcesandEights pointed out, the 3.6 puts out 16% more torque through the drivetrain.

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).

To be clear, my statements about owning one were directed at knowing why transfer case gear ratios were chosen, etc. People make blanket statements about gearing because of what worked in their rock crawling 98 TJ With a straight 6 or possibly an LS conversion.

I agree with most of your comments Jason. And yes, everywhere I’ve gone in Moab, etc with it, I’ve also gone in my old 3.6 motors. HOWEVER, this is a hell of a lot more fun during the process! Those dirt/sand sections between the rocks in Moab where you used to fill the time talking on the radio with your buddies or arguing with your wife/kids, I’m mashing the throttle and laughing or smiling the whole time. Snow is about the same performance as my prior motors, just worse fuel economy (but as everyone keeps pointing out the reasons people do or don’t buy jeeps, no one buys them for fuel economy). Daily driving is more fun, I smile every time I start the Jeep - that never happened with prior jeeps. And finally, I live an hour from some great sand dunes, where there is no comparison - this thing is absolutely amazing in the dunes! I’ll let this video speak for itself, it’s like having a street legal side by side.

Jason - another motivator for me to end up with this is that I was able to take EVERYTHING from my 19 JL (all my current mods), down to pulling the hydro bumps and drivelines and put it into my 392. That made the math work out to less than a motor swap would have cost in my old one.


Aces, others have talked about 2wd way more than I have in this thread. I could really care less about street driving. The main reason I keep it in 2wd all the time is I have an Ultimate Dana 44 front axle with regular Ujoints. Not something I want under power all the time. And there are always haters- someone asked me about warranties (I didn’t bring it up to brag), and I said I voided it (ie. 37”s, regearing, trussing the axle, aftermarket shafts, etc…). If I would have complained about the dealer not covering it, would you have hated on me for that too? Looks like you’re only 2-3 hours south of me, if you want to meet up in Florence, I’d be glad to give you a ride in the dunes. It might change your mind, or at least let you experience how fun and capable these things are. My friends that have similar backgrounds to all of you: fast cars, wheeling for years, etc. are all a bit mind-blown after riding in or driving this. If I would have known how much fun it would be, I would have had a conversion done years ago.

And that's where HP has a GINORMOUS advantage, in the sand. Throwing sand is analogous to a prop moving air or water. Having done that with my 400 HP 66 Chevy I can attest to the fun factor. But given I only crawl now, HP has disadvantages and no advantages to me.

 

[AcesandEights]

...

Aces, ... Looks like you’re only 2-3 hours south of me, if you want to meet up in Florence, I’d be glad to give you a ride in the dunes. It might change your mind, or at least let you experience how fun and capable these things are...

I just got back from Coos Bay a few days ago (spent Xmas there). I might PM you next time I'm over there (once a month, more or less), although the dunes aren't as fun for me as the mountains are. Next time I have a permit to do the McGrew (between O'Brien/Cave Junction and Brookings) I'll let you know, if you'd be interested in that as well.

 

[1996cc]

I just got back from Coos Bay a few days ago (spent Xmas there). I might PM you next time I'm over there (once a month, more or less), although the dunes aren't as fun for me as the mountains are. Next time I have a permit to do the McGrew (between O'Brien/Cave Junction and Brookings) I'll let you know, if you'd be interested in that as well.

McGrew is a great trail. I’d like to do it again.

 

[Slippery Pete]

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).

I have a 2.0 Willys XR (4.56), so would this calculation be accurate?..

295 * 4.71 * 2.72 * 4.56 = 17,234

I'm a noob to this stuff, my question is would getting 37's be detrimental to the differential/axels?
Thanks!

 

[JeepinJason33]

Smiles per gallon is what my neighbor calls it. I can't argue with that. Just does not make sense for me. Now, if they come out with a 392 with the Dana 60's from the factory at under 100k, I could certainly be swayed into purchasing one.

 

[1996cc]

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