392 Dana 44 axles beefed up for 392?

jessedacri

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thanks for the clarification. That’s kinda what I meant ... although I wouldn’t use the word ‘symbolically’. the 392 does not have the FAD system at all - it is deleted. But, to your point, the hole in the housing is still there. Not sure it’s weak, though. Weaker than a full tube? I would think .. relative. I’d certainly rather it be a solid tube.

That said, I haven’t researched failures of the housing at the FAD opening. Maybe that’s an issue I’m unaware of???

great to know it is actually a one piece axle and not collared. That was one of the big questions I’d wondered since it was brought up earlier.
This is a case of “ask me how I know” - I bent my JLR’s front axle at the FAD housing and dropped $4600 on a UD44 to avoid it happening again, and I’m only running 35s. It’s a poor design. I ran across someone else in my area who was also seeking a replacement axle for the same reason at the same time, his completely snapped at that area.

The cast FAD housing is the weakest part. You can easily toss upgraded shafts in to eliminate the FAD itself but the housing itself is the weak point. I would at the very least truss it if I were a new Jeep owner.





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jessedacri

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Seems HD collars just for the FAD housing to axle tubes should/could be offered by after market suppliers.
It's tough - I've seen multiple types of failures, but typically what happens is the cast FAD housing itself comes apart. The spot welds holding the short tubes in fail under heavy load and then start tearing the cast housing. I think the best preventative anyone can do with these is the Artec or Rusty's truss - rusty's especially has a collar type piece in theirs designed to strengthen the fad tube entry (although mine failed more significantly at the *outer* tube and FAD connection):
rc-ramtx4400-jljt-on-axle-greyed-wm-web.jpg
 

DadJokes

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So is the Mojave the same with as a Rubicon or standard with JT or JL?
 
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sourdough

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It's tough - I've seen multiple types of failures, but typically what happens is the cast FAD housing itself comes apart. The spot welds holding the short tubes in fail under heavy load and then start tearing the cast housing. I think the best preventative anyone can do with these is the Artec or Rusty's truss - rusty's especially has a collar type piece in theirs designed to strengthen the fad tube entry (although mine failed more significantly at the *outer* tube and FAD connection):
rc-ramtx4400-jljt-on-axle-greyed-wm-web.jpg
Nice. But welding cold rolled metal to cast metal is out of my comfort zone. Heard to do right you preheat cast metal and cool slowly after welding. Sounds tough to do unless the axle was stripped and on a stand. I'm more of a simple R&R guy now. If itdoesn't bolt it on, it's not going in my cart.
 

Comac90

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This is a case of “ask me how I know” - I bent my JLR’s front axle at the FAD housing and dropped $4600 on a UD44 to avoid it happening again, and I’m only running 35s. It’s a poor design. I ran across someone else in my area who was also seeking a replacement axle for the same reason at the same time, his completely snapped at that area.

The cast FAD housing is the weakest part. You can easily toss upgraded shafts in to eliminate the FAD itself but the housing itself is the weak point. I would at the very least truss it if I were a new Jeep owner.
Out of curiosity, what happened when the housing failed? What kind of terrain, speed, etc?
 

BCMgunner

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392 on 37” KO2s
012CBC2D-37BB-434D-9496-9EA3171B79BB.jpeg

FWIW, MetalCloak rear diff skid for standard Rubi fit perfectly on the 392. Answers our question about axle diameter differing from standard Rubi.
 
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sourdough

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They might have changed the tube I.D. FYI, back in the day if you wanted a strong tubed D44. Chevy 3/4T trucks had a 2.75 O.D. tube with 1/2" thick walls vs Jeeps 2.75 O.D. with 3/8" walls.
 

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