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front axle swap


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13 minutes ago, Chad said:

What axles can I use for a almost direct fit for my front axle for danna 44s on my mj I think I’m going to go with the ford 9 inch for the rear 

 

depends on what you mean by "almost".  only the TJ front 44 will swap with no welding and it won't match the fullsize 9". 

 

the front axle is always the most challenging of the 2.  choose it, and then pick the matching rear. :L: 

 

also, the 9" is overrated.  I ruined my center section on a freakin' rock of all things. :fistshake2: 

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Some companies make a truss with built in TJ/XJ/MJ brackets. I’m thinking Artec and maybe TNT have some. You can see what axles they have them available for and pick your axle accordingly. I know you can go with a JK D44 front with one of those kits. You’ll still have to cut off all the brackets and a lot of welding will be involved. Pretty much the case with any upgrade axle swap. 

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1 hour ago, Jesse J said:

any where to get j yard front d44? preferably with a 4.5x5 

 

the only one with the MJ pattern will be a TJ Rubicon 44. :L:   try car-part.com and be prepared for a little sticker shock. :(

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Yep.  TJ/LJ Rubicon (2003 to 2006) is the only bolt in donor available.  They're rare and command a premium price tag, even with the inferior locker they use.

 

Everything else will require welding on brackets.  And none of the other Dana 44's use the 5 on 4.5" bolt pattern to match the rear.

 

If you're set on a Dana 44, it's easier to get a donor and find the matching rear from the same or similar donor so that you have a matching bolt pattern front and rear.  The rear is easy.  Spring perches and maybe shock mounts if you can't reuse the factory spring plates.

 

Most common donor for the front is the narrow track 1980-1991 Jeep (Grand) Wagoneer (no "Grand" from 80-83) and 80-83 Cherokee.  1979 and older are passenger side drop so they don't work well.  They are very close to the same width as a stock XJ/MJ axle.  They have a 6 on 5.5" bolt pattern.  The matching rear is an inch or three narrower but it's easy to put on some spacers.  There are other options for a rear that will have the same bolt pattern.

 

The wide track Cherokee (80-83) and J10/J20 pickups are donor candidates if you want a wider wheel track.

 

Another donor that people use is the mid to late 70's Ford F150 and F250.  They use a high pinion Dana 44 (stronger) but I think they're a little bit wider than the stock XJ/MJ axle.  The F150 uses a 5 on 5.5" bolt pattern.  The F250, an 8 on 6.5".  The F150 has a 9" rear to match, and the F250 uses a not entirely desirable full float Dana 60.

 

The 9" has the potential to be a good axle but it requires a little bit of investment to get it there.  Fortunately, it's well supported in the aftermarket so it's easy to find what you need.

 

One important thing to note, when upgrading to a front Dana 44, you will need to get a shorter front driveshaft.  Depending on which axle you started with and which one you go with, you will likely also need to shorten the rear driveshaft as well.

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Before choosing your axles, you need to determine tire size. The whole purpose of swapping axles is to swing bigger tires. Bigger tires are the only way to gain clearance under the axle itself. However, bigger axles are just that, bigger. So you need more tire size again to compensate for the size of the diff. Larger tires means deeper gearing and thus the death spiral starts. 
Another important factor here is unsprung weight. In other words, how much does everything below the springs weigh. Bigger axles and tires  can dramatically increase this number. 
Asking what the best axle is is like asking for the highest number you can think of. Given the amount of lift and trimming needed to fit large tires on an MJ I’d stick with 37’s if it will ever see pavement. A built lp 44 and above can handle 37’s without much fear. But then again anything can be broken. Some get by on a super D30 and others are braking high 9’s on the same setup. Consider though that an HP 

30 on 35’s can be a very competitive setup given that, to run 37’s, you are likely going to have to run an axle with less ground clearance. In other words, there is always a trade off. 

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2 hours ago, BeatCJ said:

Sure they would. And Chrysler would have passed the premium price on to the buyer.

 

The TJR d44 front was really just the diff. Everything else was a d30. I know when they came out with the JK “HD” 44 rear, it had already been out for almost a decade but gained popularity and recognition with the JK release. Nothing new, just reused/repurposed leftovers. I haven’t seen Dana/Spicer make any complete one-off item that was only on one model vehicle.

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On 2/15/2021 at 8:52 AM, derf said:

Yep.  TJ/LJ Rubicon (2003 to 2006) is the only bolt in donor available.  They're rare and command a premium price tag, even with the inferior locker they use.

 

Everything else will require welding on brackets.  And none of the other Dana 44's use the 5 on 4.5" bolt pattern to match the rear.

 

If you're set on a Dana 44, it's easier to get a donor and find the matching rear from the same or similar donor so that you have a matching bolt pattern front and rear.  The rear is easy.  Spring perches and maybe shock mounts if you can't reuse the factory spring plates.

 

Most common donor for the front is the narrow track 1980-1991 Jeep (Grand) Wagoneer (no "Grand" from 80-83) and 80-83 Cherokee.  1979 and older are passenger side drop so they don't work well.  They are very close to the same width as a stock XJ/MJ axle.  They have a 6 on 5.5" bolt pattern.  The matching rear is an inch or three narrower but it's easy to put on some spacers.  There are other options for a rear that will have the same bolt pattern.

 

The wide track Cherokee (80-83) and J10/J20 pickups are donor candidates if you want a wider wheel track.

 

Another donor that people use is the mid to late 70's Ford F150 and F250.  They use a high pinion Dana 44 (stronger) but I think they're a little bit wider than the stock XJ/MJ axle.  The F150 uses a 5 on 5.5" bolt pattern.  The F250, an 8 on 6.5".  The F150 has a 9" rear to match, and the F250 uses a not entirely desirable full float Dana 60.

 

The 9" has the potential to be a good axle but it requires a little bit of investment to get it there.  Fortunately, it's well supported in the aftermarket so it's easy to find what you need.

 

One important thing to note, when upgrading to a front Dana 44, you will need to get a shorter front driveshaft.  Depending on which axle you started with and which one you go with, you will likely also need to shorten the rear driveshaft as well.

I only want to run a front d44 with a 5x4.5 is becauseI have a stock rear one. can you swap the hubs?

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Not really.  The TJ/LJ uses hubs and knuckles that are unique to that axle (and the matching Dana 30).  Full size trucks that used Dana 44's had different outers that were built completely differently and use different knuckles.  The JK/JL uses a different system too.

 

There is some overlap between the 44's from the 70's and 80's so you can run Chevy/Jeep knuckles on a Ford 44.  But old school Dana 44's can't run a 5 on 4.5" pattern without custom pieces and I don't know if they're available or not (I suspect not).

 

I took some pictures when I rebuilt the outers on the Dana 44 in my J10 and posted them here:  http://grimmjeeper.com/TruckNorris/rotor.html

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3 minutes ago, Jesse J said:

I only want to run a front d44 with a 5x4.5 is becauseI have a stock rear one. can you swap the hubs?


The only d44 axle that bolts in to our MJs as was mentioned is a TJ rubicon front. Most will cost more that many paid for their trucks. For the most part, Jeep hasn’t used any “hubs” since 1986 on the CJ7. Unit bearings are what our axles all run. Some have converted Dana 30’s and 44’s to Ford locking hubs but they are petite with the 5 on 4.5 pattern. I know many balk at running another wheel pattern but the 6 on 5.5 from a grand Wagoneers plus a rodeo HD44 is quite a nice combo. Obviously, you’ll need new wheels. But again, if your running 35’s or below, our HP D30s are not a ticking time bomb and hold up just fine. And for the most part, your front axle will see far less torque than the rear.

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2 minutes ago, ghetdjc320 said:


The only d44 axle that bolts in to our MJs as was mentioned is a TJ rubicon front. Most will cost more that many paid for their trucks. For the most part, Jeep hasn’t used any “hubs” since 1986 on the CJ7. Unit bearings are what our axles all run. Some have converted Dana 30’s and 44’s to Ford locking hubs but they are petite with the 5 on 4.5 pattern. I know many balk at running another wheel pattern but the 6 on 5.5 from a grand Wagoneers plus a rodeo HD44 is quite a nice combo. Obviously, you’ll need new wheels. But again, if your running 35’s or below, our HP D30s are not a ticking time bomb and hold up just fine. And for the most part, your front axle will see far less torque than the rear.

yeah that's a good point. from a strictly personal point of view I really don't like the sound of putting gears in a d30 like sure will it probably be fine. but I was raised by a structural engineer to build bomber $#!&. Is there any way to get a 4.5x5 on a dana 44?

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19 minutes ago, Jesse J said:

yeah that's a good point. from a strictly personal point of view I really don't like the sound of putting gears in a d30 like sure will it probably be fine. but I was raised by a structural engineer to build bomber $#!&. Is there any way to get a 4.5x5 on a dana 44?


With lots of money, yes. Buy a TJ rubicon front. But it is really not a “true” D44. Only the ring and pinion are D44 size. Plus they are a low pinion design which is inherently a weaker design than a high pinion for the front axle. For a TJ they either ran a low pinion 30 or a low pinion 44 up front. Obviously the front 44 would be stronger vs the LP30 but a high pinion 30 is very close if not the same in terms of real world strength to a 44 TJ rubicon axle. 

All these TJ rubicon front 44’s were really not the stoutest versions of the axle. Nothing like the old Dana 44’s with hubs and big axle tubes. The new generation 44’s are also substantially stronger. If you grab a “real” 44 front from a grand wagoneer or older Ford or Chevy truck you’ll be surprised how much heavier it is than your stock rear 44. But your not going to run 5x4.5 and have decent hubs. Although the 5x4.5 pattern is not an inherent weakness in the axle, it is not an HD truck pattern. It’s a Ranger, Explorer, XJ, TJ, ZJ, MJ etc pattern. None of those are what I would consider a “heavy duty” truck. So when you want to step up to real heavy duty axles, your not going to find the relatively small 5x4.5 pattern. The spindle is just too small. 
 

And just to throw this out there, the stock MJ/XJ 44 rear is a neat option and stronger than a stock D35 for sure but sometimes the strength is a little overstated. They are still a lightweight truck axle. An HP30 matches those stock 44’s very well.

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1 hour ago, ghetdjc320 said:


With lots of money, yes. Buy a TJ rubicon front. But it is really not a “true” D44. Only the ring and pinion are D44 size. Plus they are a low pinion design which is inherently a weaker design than a high pinion for the front axle. For a TJ they either ran a low pinion 30 or a low pinion 44 up front. Obviously the front 44 would be stronger vs the LP30 but a high pinion 30 is very close if not the same in terms of real world strength to a 44 TJ rubicon axle. 

All these TJ rubicon front 44’s were really not the stoutest versions of the axle. Nothing like the old Dana 44’s with hubs and big axle tubes. The new generation 44’s are also substantially stronger. If you grab a “real” 44 front from a grand wagoneer or older Ford or Chevy truck you’ll be surprised how much heavier it is than your stock rear 44. But your not going to run 5x4.5 and have decent hubs. Although the 5x4.5 pattern is not an inherent weakness in the axle, it is not an HD truck pattern. It’s a Ranger, Explorer, XJ, TJ, ZJ, MJ etc pattern. None of those are what I would consider a “heavy duty” truck. So when you want to step up to real heavy duty axles, your not going to find the relatively small 5x4.5 pattern. The spindle is just too small. 
 

And just to throw this out there, the stock MJ/XJ 44 rear is a neat option and stronger than a stock D35 for sure but sometimes the strength is a little overstated. They are still a lightweight truck axle. An HP30 matches those stock 44’s very well.

all thing's to consider. thanks!

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