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Is My Front Axle a Ticking Time Bomb?

4K views 31 replies 16 participants last post by  GreenMachine13 
#1 ·
Lots of conflicting stuff about the relative strength of the front axles on JKs. Some people throw on 37’s and bead locks and seemingly wheel the heck out of their rig with no problems. Others tell stories of some random Sport with stock tires that ends up with bent axle tubes and outer C’s after hitting a pothole. To say the least, it is confusing and a bit worrisome. That’s why I’m doing this. I worry about it and I want as much info as possible. I’m sure others do to.

I thought in the vein of some of the other tech threads, this could be a repository for opinions, advice and solutions. I’m not looking to start some kind of flame war. All opinions should be welcome as long as they can be backed up by some kind of evidence, which might include personal experience. The “My brother-in-law told me about this one guy that heard this story about this other guy...” type of stuff isn’t helpful...unless you have pics of the carnage. :D

So, I’ll begin. This is what I know (or think I know so correct me if necessary):


  • Other than the diff housing and the size of the ring and pinion, the D30 and D44 axles are basically the same.
  • The problem seems to be the relatively thin walls of the axle tubes and the weak outer C’s.
  • This is primarily a front axle issue due to several reasons like the rear axle is the trailing axle, the front has the long tube on one side, the front axles sees steering forces, etc.
  • Bigger/heavier wheels and tires increase the potential for damage.

There are several option to correct this as far as I can tell:


  • Do nothing. Don’t worry about it, take it easy when off road or fix the axle if it breaks.
  • Install lighter, smaller wheels and tires.
  • Sleeve the axle tubes, truss the axle and/or install C-gussets.
  • Get an aftermarket housing with thicker tubes and heavier outer C’s.

Obviously, those get more expensive as you go down the list. From what I can tell, sleeves, trusses and/or gussets will run you $500-$800 give or take depending on how it’s done, whether you change ball joints and if you upgrade other components. Those all require welding and disassembly of the axle. In other words, not an option for most DIY Jeepers.

A new axle housing is about $2000 plus labor to install your stock guts (More if you regear, add lockers, upgrade axle shafts, etc.)

So, here’s the fun part. Discuss these questions:


  • Is the front axle a ticking time bomb just waiting for the right pothole to be twisted into a pretzel or is it good enough for the typical JK owner (90% road, 10% off)?
  • Are most of us good to go up to 35 inch tires, the lighter the better?
  • What have you done to your axle and why? If you’ve chosen not to do anything, why?
  • Finally, does disconnecting the sway bar and airing down when off road help protect the axle from damage? I think those will help but what do you think?

 
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#2 ·
My Dana 30 took quite a beating for a year on 37's with nothing more than an artec truss and alloyusa balljoints. It is surprisingly strong, I have torn mine apart and thought "this is all thats holding this thing together??"

ring gear finally gave up after I blew my rear driveshaft and tried to drive in reverse. hence the 1 tons
 
#4 ·
I'm driving a more or less stock JK Sport and beat on the front axle regularly and ruthlessly, going over sand dunes. Probably hundreds a week (I live/work in a desert area with large open dune fields). The axle has held up for 3 years. The steering damper was bent (never fixed, seems to be fine that way), the air dam fell off, the read bumper cover fell off, but the axle is fine (Thank God).
 
#5 · (Edited)
http://www.wranglerforum.com/f314/kjeepers-build-thread-385602.html

^^^Read through this build Thread. Start with Post 57, and pick out the Posts, that are applicable!!!!!

This should answer most of your questions.
Kjeeper10, has spent a lot of money and time beefing his axles up, and their is a justifiable reason, behind his logic, and it's called longevity!!!!

So enjoy his Build Thread, because this guy knows what he is doing, from experience........:thumb:
 
#6 ·
That's good advice. Always appreciate kjeeper's knowledge. Still, I'm hoping this become kind of the repository for discussions about front axles. A one stop shop so to speak.

To the point, longevity is something I didn't discuss. I plan to drive this Jeep for at least ten years (I wouldn't drop thousands of dollars on mods if I was going to trade it in soon).
 
#7 ·
Dan, your Threads original Post # 1 is excellent, which shows that you already have a in depth knowledge of the issue.

My only other comment is that, driving habit's, how hard that you are on the peddle, plays a major role in axle assembly longevity.
If you get it bouncing, and shock load the hell out of it, then BAM...:atomic:
Go easy on the foot, and use common sense, and even many stock, NON-MODED ones, will have longevity.
But many don't have the experience off road, and therefore learn the hard way. So in their case, they are better off to beef them up in advance, and be pro-active, rather than a re-active disaster............:thumb:
 
#8 ·
Thanks Bill,

It really comes down to the type and hard you wheel the jeep. I would gusset #1 regardless of 30/44
Some say it's not worth spending a dime on axles. I saved a lot of money having a friend do the work :thumb:
When I picked up my tires, he had his front 30 sitting out. The guy had outer sleeves and inner sleeves. The axle was beefy as hell, but The biggest concern (as you know) is the size of the ring/pinion gears. Somebody mentioned cyro-treating (or something like that) to make the metal stronger ? I don't know anybody who's done it or any info on the process. Iirc the gears are sent in and returned strengthened.
 
#9 ·
I've seen how some guys attack obstacles off road. I usually baby mine. I approach rocks, ledges, gullies, etc. slow. I rarely hit abrupt edges or non-moveable objects hard. That's not to protect the axle, it's just how I approach off-roading. I'll do 50 mph and on a flat dirt road but over obstacles I take it slow.

Honestly, you can't find too many threads about broken/bent axles on here and if you take into account the fact that guys with 35's without axle damage aren't posting to let us know everything is still good, the numbers are pretty low.

I don't have any evidence but I'd suspect airing down your tires and disconnecting help the axle articulate and the tires and springs absorb a lot of the force instead of the axle.
 
#11 ·
Standard operating procedure or just for hard use Jeeps? I was thinking gussets and ball joints (as long as you're in there, right?) and calling it good.

Then again, If I want to check the Rubicon Trail off my bucket list, sleeves might not hurt. Or I might do nothing and if it breaks or bends I'll get a beefed up D44 axles and throw my stock guts in it.
 
#13 ·
I have built up my axles.. ..truss..sleave..c-gusset, RCV axles or good u-joints and chrome moly axles will do great in a 30 or 44.

My weakness is in running 5.13 gear..the pinon is very small.

I also run ARB (front) & OX (rear) lockers
 
#14 ·
My Artec Truss was about $750 installed, I had the Dynatrac Ball Joints done at the same time. ($110 labor, $450 parts) There was a $100 rebate going on the joints at the time..
I'll replace the axels after the 1st of the year and I'll go with new Drive Shafts in a month or two...
I would rather do a ounce of prevention now instead of a pound of cure later...

The upgrade I need right now is a tire carrier upgrade...
And the one I want the most is a Behr Brake upgrade :)
 
#15 ·
A larger O.D. tube will add far more strength than adding a sleeve or making the tube thicker. Sleeves will add about a 30% increase in strength; if you were going to bend it without sleeves you would probably bend it just a little less with sleeves. Adding gussets would be worthwhile if you plan on keeping the stock axle housing. No one here can describe what hard wheeling would be for you, one man's easy trail is a nightmare for another. I didn't bother throwing money at the stock Dana 44 housing and bought a Tera44 housing with 3.25x0.25" tubes. I wish I had bought a ProRock 44 housing now but either one is considerably stronger than the stock housing with its 2.5x0.25" tubes. Another thing to think about are the thin brackets on the stock housing.
 
#17 ·
Right off the bat I replaced my D30 front with a Dynatrac PR 44. I've been on to many trails, back when I was running my 2003 rubi, where someone had axle problems. I really felt bad for them because some of these trails were pretty tough and if the part couldn't be replaced on the trail it became a real challenge to get the rig out of there. I just didn't want to be caught in that situation.
 
#18 ·
OP, I ran 37s on a Sahara with a 4.5" lift that netted over 5" so the pinion angle was not optimum. It will hold up as long as you don't do something dumb like wedged the tires in the rocks while the steering wheel is turned and then apply a lot of throttle. You don't have to baby it but you do have to be aware of it and drive accordingly. Similar to an engine, you shouldn't redline it every time you shift with a manual.

I disagree with your statement that the D30 and D40 gears are essentially the same. They are not and difference becomes more important at the gear ratio gets numerically higher. I know it always depends on how and where you drive but IMO the gears are the weakest link when you run big tires on the D30. I liked the 37s off road and it is fun to just roll over smaller obstacles but IMHO don't think they are necessary unless you spend at least 30-40% crawling when you are off road. On most trails the 35s are perfect match for the JK and the difference can easily be made up with driving skills.

This outside thread has some decent specs and discussion on the two diffs:

Dana 30 vs Dana 44

So to answer your question, IMO your front axle is only a ticking time bomb if you drive care free/careless off road.
 
#23 ·
^^^X2, the key words are OTHER THAN!!!!!!!!
 
#24 ·
Ha, I'm vindicated! I said ring and pinion instead of just gears. The D44 gears are bigger and therefore stronger than the D30.

But back to Spinlock's statement. That's the confusion a lot of us feel. One man's easy trail is another man's nightmare. He's saying don't worry about but a lot of others are saying sleeve and gusset at a minimum. Hmm. That's why I posed the question but I wonder if there is a right answer. Like I said, I've seen how some guys attack obstacles, engine revving, tires spinning, hammering into them, bouncing and jouncing about with little regard for their Jeeps (I mean they love them but are prepared to replace broken parts, on the trail if necessary).

I avoid situations where damage is likely. I pick the best line, a creep up to and over obstacles. If I can't do it, I back up and pick a better line or go around. I'm not afraid to test my skills or my Jeep but I'm not looking to prove anything either. Most of my off road time is on fairly moderate trails not playing in rock gardens.

But the longevity argument makes me think it might be a good idea to consider something. I keep going back to gussets and ball joints (since I'm in there). I might be more confused than I was when I posted.
 
#32 ·
I've been on a few wheeling trips now with large groups of jeeps.

Here is what I've gathered from talking with them.

First, a lot of folks don't have a clue about their axles... I needed to talk to many people to find the ones with knowledge.

The ones without a clue claim that everything is fine and have no issues with larger tires, etc.

Of the ones with knowledge, they say that the new D30 holds up pretty well but it will eventually fail if wheeled hard. Ball joint and wheel bearings are ticking time bomb.

I've witnesses several incidents of trail damage. All rubicons running stock axles with 35s. They would get bound up while locked and the front you joints would blow and the axle shafts would get the ears ripped off.

I think they could have avoided this damage by not trying to power through obstacles while bound up. Lack of off road driving experience.

I've also encountered several jeeps with noticeably tweaked Cs (both the 30 and 44). The jeeps typically had heavy tire / wheel combos but not always. One guy with 33s tweaked them but he wasn't sure how or when it happened.

My friend's jeep was purchased with noticeably bent axle tubes and Cs, both front 30 and rear 44! He knew this when he bought it. He's swapping both axles for ProRocks because be building it to be off road only.

So in my view, the axles will hold up well enough if driven carefully and smartly but they will need some attention for ball joints and wheel bearings. There is also no guarantee that they won't get tweaked if circumstances are just right to do it.

My plan is to gusset my 30 and drive it gingerly off road until I've saved enough for a prorock.
 
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