30 44 ?
JK Super Freak
Joined: Oct 2010
Posts: 1,255
Likes: 1
From: clinton, ok
Those are Dana axle numbers. The 30 is the smallest axle that dana makes the 44 is the next size up. The bigger the number the bigger the ring gear is in diameter. The dana 60 is used on some half ton trucks or used to be as a rear axle and then they would have a 44 up front. Most heavy duty 3/4 ton and 1 ton trucks would have a dana 80 in the back and then a 60 up front.
The axle shafts also get larger in diameter with the bigger axle assemblies and they have higher spline counts. The splines are what engage with the gears inside the diff and actually drive the axles. The axles shafts are so large on the dana 80 that they almost never break, I have seen them with all the splines stripped off.
There are actually a couple more dana axle numbers but the ones I gave you here are the most commonly used ones.
Hope this helps out a little. You can probably do a search using Bing or another search engine and fine other stuff on the web if you wanted to know more.
The axle shafts also get larger in diameter with the bigger axle assemblies and they have higher spline counts. The splines are what engage with the gears inside the diff and actually drive the axles. The axles shafts are so large on the dana 80 that they almost never break, I have seen them with all the splines stripped off.
There are actually a couple more dana axle numbers but the ones I gave you here are the most commonly used ones.
Hope this helps out a little. You can probably do a search using Bing or another search engine and fine other stuff on the web if you wanted to know more.
Sponsoring Manufacturer
Joined: Dec 2008
Posts: 1,136
Likes: 4
From: Huntington Beach, CA
There is a bit more to it than the previous explanation but most of it is right-on.
Early on, the 44 was named due to it's torque handling capability (4,400 lbs torque). I don't know if this is true with any of the other designations. Now, it just refers to a ring & pinion basic size but that's not really even correct anymore. Current JK Dana 44 R&Ps can't fit into the average 44 housing. We've heard that Dana wanted to change the series number but they met with resistance from Chrysler/Jeep.
Much of the difference in size isn't for axle breaking strength but for axle assembly carrying capability. As an example, all Excursions and many early Ford Super Duty 4x4 trucks came with a Dana 50 front axle assembly. While this LOOKED like a D60, the internals were nearly identical to a D44. A D44 locker can be installed with added sleeves on the diff bearing journals. The outer axles were the same 30 sp units used on a 60 and the same u-joints were used. The axle shafts themselves started at the yoke like a 60 shaft but tapered down to 30 spline at the diff. Basically it was a 44 that had a HD housing to support a very heavy truck.
Many of the larger Dana axles used the same 35 spine axle shafts. The difference was the R&P size and overall housing strength. They were designed to carry more weight, not necessarily more power.
In the off road world we're far more concerned with torque output and traction than weight required housing strength. While the Dana 30 is adequate for a stock rig, it needs help and a fairly light foot if used in tough off road use. While I've only heard of a single (just 1) front Dana 44 JK R&P failure, we've heard of numerous JK 30 failures. My opinion of the stock JK front axle assembly (30 or 44) in a well used off road rig is well documented so I won't go any further here.
Early on, the 44 was named due to it's torque handling capability (4,400 lbs torque). I don't know if this is true with any of the other designations. Now, it just refers to a ring & pinion basic size but that's not really even correct anymore. Current JK Dana 44 R&Ps can't fit into the average 44 housing. We've heard that Dana wanted to change the series number but they met with resistance from Chrysler/Jeep.
Much of the difference in size isn't for axle breaking strength but for axle assembly carrying capability. As an example, all Excursions and many early Ford Super Duty 4x4 trucks came with a Dana 50 front axle assembly. While this LOOKED like a D60, the internals were nearly identical to a D44. A D44 locker can be installed with added sleeves on the diff bearing journals. The outer axles were the same 30 sp units used on a 60 and the same u-joints were used. The axle shafts themselves started at the yoke like a 60 shaft but tapered down to 30 spline at the diff. Basically it was a 44 that had a HD housing to support a very heavy truck.
Many of the larger Dana axles used the same 35 spine axle shafts. The difference was the R&P size and overall housing strength. They were designed to carry more weight, not necessarily more power.
In the off road world we're far more concerned with torque output and traction than weight required housing strength. While the Dana 30 is adequate for a stock rig, it needs help and a fairly light foot if used in tough off road use. While I've only heard of a single (just 1) front Dana 44 JK R&P failure, we've heard of numerous JK 30 failures. My opinion of the stock JK front axle assembly (30 or 44) in a well used off road rig is well documented so I won't go any further here.
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JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Click on 'Dynatrac' in the upper left of their posts, View Profile, Find all posts...
There are posts daily detailing the issues people are having with these axles, that is why strengthening them is so popular. Or search on 'gussets' and 'sleeves' and you should find plenty of info.
There are posts daily detailing the issues people are having with these axles, that is why strengthening them is so popular. Or search on 'gussets' and 'sleeves' and you should find plenty of info.
Sponsoring Manufacturer
Joined: Dec 2008
Posts: 1,136
Likes: 4
From: Huntington Beach, CA
^^ he is correct.
The ProRock 44 is a much better end solution than any modified stock housing. The only advantage a stock housing offers is the ability to do mods as your budget allows as, obviously, buying a ProRock requires a large up-front investment. To me, a D30 owner will see a huge benefit to doing a ProRock rather than spending ANY money building up a 30. I've got buddies that spent tons on their 30s only to later swap them out. Financially, especially if you can handle the cost up front, I think most will say that PR44 is a good investment.
You'll find many here on this board that would have done things differently if the PR44 had been available when they started their builds.
Check here for PR44 info https://www.jk-forum.com/forums/show...-Forum-Members!
The ProRock 44 is a much better end solution than any modified stock housing. The only advantage a stock housing offers is the ability to do mods as your budget allows as, obviously, buying a ProRock requires a large up-front investment. To me, a D30 owner will see a huge benefit to doing a ProRock rather than spending ANY money building up a 30. I've got buddies that spent tons on their 30s only to later swap them out. Financially, especially if you can handle the cost up front, I think most will say that PR44 is a good investment.
You'll find many here on this board that would have done things differently if the PR44 had been available when they started their builds.
Check here for PR44 info https://www.jk-forum.com/forums/show...-Forum-Members!
