Jeep Wrangler Forum banner

Difference between Dana 30 and Dana 44

42K views 45 replies 20 participants last post by  derf 
#1 ·
I've seen several threads about people swapping/upgrading their axles, but I would like to read about the differences in the two. I am not a mechanic by any stretch. Is there something that I can read in laymans terms that explains the capabilities and limitations of each axle? I have a JKU Sahara on order and am curious about what I will get stock in teh dana 30 front/Dana 44 rear
 
#3 ·
On a JK the 44 has a beefier center section and I believe stronger (more splines) axle shafts. For a stock rig I'd say there are no limitations. Once you go 35s or bigger I think is where strength can become an issue on either axle.
 
#6 ·
He could go with a Dana 60, then he would have 30 more, or twice as much....;)
 
#9 ·
The difference is, Snap, Crackle, POP off road!

I have broken two rear axles on my 13 year run with the 30/35's. Of course that was after regearing to 4.10s, installing a locker and 33" tires. Always was easy on the skinny petal.
 
#10 ·
The factory Dana 30 is the light duty axle that is cheap to build and lasts as long as the Chrysler warranty. So it goes in the non-Rubicon Jeeps. When they went from the 2006 and older TJ Wrangler to the JK, they redesigned the Dana 30 so it's a little stronger. But not much. It's fine to get started but it's somewhat weak, especially as you start to modify the Jeep.

The factory Rubicon front Dana 44 is a very slightly upgraded axle over the Dana 30. The differential is upgraded to use larger and stronger gears and they put thicker axle shafts between the locker and the u-joint at the steering knuckle. Everything else about the axle is the same. The axle tubes, the suspension brackets, the steering pieces, everything. It is not a very strong axle compared to a "real" Dana 44.

Before they all switched to independent front suspension, older 1/2 ton trucks (including full size SUV's and Jeeps) used a "real" Dana 44 that had bigger, thicker axle tubes and stronger steering components. But they're not always easy to swap in to a Wrangler for various reasons.

Aftermarket companies have designed upgraded Dana 44 axles that are designed to bolt into a Wrangler directly. They are designed from the ground up to be beefier and stronger than even "real" Dana 44's in older generation vehicles. They use the bigger, stronger axle gears inside of a heavier duty differential housing. They have bigger, thicker axle tubes, beefier steering components, and suspension brackets made from thicker, stronger material. They are actually almost as strong as a Dana 60 (3/4 and 1 ton pickup front axle) in some ways.


Why does this matter?

Because taking a Jeep off road puts a lot of stress on an axle. The factory Dana 30 and Rubicon Dana 44 aren't really built for serious abuse. They can be patched with some weld on parts to beef them up but in the end, they're 1/4 ton axles and they just don't hold up if you run anything bigger than a 35" tire on moderate trails and above.

If you plan on serious off road driving with big tires, you really need to upgrade from factory to aftermarket (or modify and swap in something beefy from a heavy duty donor vehicle).

If you're just going to hit dirt roads and remote camping spots and never put on bigger tires or abuse the Jeep in any way, the stock Dana 30 is adequate. Though a couple of minor reinforcements wouldn't hurt.

And that's pretty much it.
 
#16 · (Edited)
Most of the TJ's have Dana 35 rear diffs.
The TJ Rubicons all have Dana 44's, but of the older version!
Some of the Sport and Sahara model TJ's also have Dana 44 rears, with rear disk brakes. These were mainly 2005 and 2006 models.

As for the JK's, only a few of the earlier 2007 models have Dana 35 rears!!!!!!!!

This weak Dana 35 axle, is only held in by C-Clips. The axle would twist off at the side gears or the C-Clip would brake and then your axle assemble and wheel would work it's way out of the housing tube. A poorly design and safetY issue..IMO
 
#17 ·
C-clips aren't that much of a problem, I plowed a lot of snow and did a lot of hauling with an 87 K20 that had the 9.5" semi-floater 14-bolt and never had a problem. Same goes for the C1500 & K10 I had (10-bolts are C-clip axles) and the several Dodge 1/2 tons (the 9.25" is also a C-clip axle.) It's definitely not an IDEAL design, but like I said I worked & wheeled those things HARD and never had a problem. I also wheeled the heck out of my '90 YJ w/33s & 3.07s - I was NOT stingy with the skinny pedal - and it was the bulletproof 4.2l that ended up breaking.

Honestly, I'd bet 75% of the time someone mentions D35s breaking, it's hearsay or some guy a friend's friend's brother-in-law's neighbor knew. Kinda like the ugly girl with the sausage in the high school bathroom, every town in America had that happen at its high school if you believe all the stories.

People break 2.5 ton and 5 ton Rockwell axles on mud trucks, so just have fun with your D30 & D35 and repair or upgrade them as needed when they break. I only take it easy with my TJ because it's also my DD, but that's what my YJ will be for when I finish it.
 
#26 ·
I too am an engineer. I know that when someone throws their credentials at me, they don't have much more to offer. I've pissed off a lot of certified "Professional Engineers" by fixing their crap for them way more times than I should have. :drinks:

To be fair, I'm sure the axle he built is plenty strong. But what he did to build it isn't an option for, well, just about everyone. Having the engineering knowledge and fabrication skills to produce that, not to mention the initiative and means to do it, is well beyond most people.

Given the fact that the aftermarket produces axle housings that are very well engineered to be dramatically stronger in every respect than the wimpy factory crap means that everyone who has the cash has the means to obtain a very stout axle that they can install with not a whole lot of effort or mechanical skill.

And that's the whole point. The Rubicon Dana 44 is a very weak axle outside of the differential housing (which is not as strong as the aftermarket units). Every reasonable thing you can do to beef it up will leave you with a differential housing that doesn't have all of the reinforcement cast into every aftermarket housing, it will still have weak axle tubes that have some strength patched into them (and no, replacing the tubes is not a "reasonable" thing for most people to do), and it certainly leaves you with the crappy cast inner C's rather than the beefy forged units offered by all the aftermarket companies.

It's interesting to see someone spend so much time and effort to rebuild a factory axle housing like that. But that's all it is. Interesting to see. Because it's probably a one shot deal that will rarely be duplicated, if ever.
 
#30 ·
He's proud of the work he did building it and he wants to show off his knowledge. It's how engineers measure themselves against other people. I know because, as an engineer, I have to consciously make the effort to not do it myself.
 
#34 ·
#35 ·
Man, that went south......you guys are definitely confusing my intentions (showing an alternative method of strengthening a weak axle housing) with a negative narrative.

It's a Dana 44, not a 30. The housing cost me $300 because it was in a fire. Everything but the housing was destroyed, hence not using any of it. Fully built, I have less into it than a comparable PR44 housing. Building is more fun for me and it was worth a try.....the end result ended up being better than I had anticipated. I would not recommend putting that kind of work into a 30, although one of the brightest minds on JF (Hendrix) did and it works great for him. Another incredibly bright mind (mrblaine, designer of many parts in this industry, including all of Savvy's products) did a very similar build to a JK 44. This may seem like a waste of time and money to some of you and that's fine.....I posted it to drive a little 'out of the box' thinking to an otherwise black and white discussion.....that's essentially what I do on this forum since it tends to need it.

I thought it would be taken positively by a few, even if it is a little OT. It has before everywhere else.
 
#36 ·
Man, that went south......you guys are definitely confusing my intentions (showing an alternative method of strengthening a weak axle housing) with a negative narrative. It's a Dana 44, not a 30. The housing cost me $300 because it was in a fire. Everything but the housing was destroyed, hence not using any of it. Fully built, I have less into it than a comparable PR44 housing. Building is more fun for me and it was worth a try.....the end result ended up being better than I had anticipated. I would not recommend putting that kind of work into a 30, although one of the brightest minds on JF (Hendrix) did and it works great for him. Another incredibly bright mind (mrblaine, designer of many parts in this industry, including all of Savvy's products) did a very similar build to a JK 44. This may seem like a waste of time and money to some of you and that's fine.....I posted it to drive a little 'out of the box' thinking to an otherwise black and white discussion.....that's essentially what I do on this forum since it tends to need it. I thought it would be taken positively by a few, even if it is a little OT. It has before everywhere else.
:thumb:
 
#45 ·
Maybe one of you can help me out.. i have a D35 in my jeep with 3.07s. I know i know. Bad idea.. anyways im wanting to regear.. i dont do much off roading at all(with this jeep). Maybe an occasional camping trip out in the woods.. anyway... What do i need to regear this thing to lets say.. 410s? Can i buy just ring and pinions? And if so what would i need for the front? 410s for that also? Or..? Im assuming the front is a D30?.. thanks for any advice!!
 
#46 ·
A D35 with 3.07 gears suggests you have a TJ or YJ, which are the previous generation Jeeps to the JK. But the answer is basically the same.

To swap gears you absolutely need to do both front and rear at the same time. At a minimum, you need gears and an installation kit for each axle. The installation kit has all the bearings and shims to properly install the gears. You also need a mechanic to do the installation. Setting up gears is precision work and has to be done right. They will usually bundle buying the parts with installation together.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top