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FAD, Keep It Or Delete It?

JTenn

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As the title says, what are the pro's and con's? Now is the time before I install my D44's.
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JTR178

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Other than saving a quarter mile per gallon with a tailwind down hill I don't see any other advantage to it. Weakest spot in the axle.
 
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JTenn

JTenn

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Other than saving a quarter mile per gallon with a tailwind down hill I don't see any other advantage to it. Weakest spot in the axle.
Agree!! My thoughts exactly.
 

bleda2002

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Aftermarket d44 or stock? Stock the casted in pinion angle is terrible so you will get driveline vibrations if you get rid of it and turn up your caster to the 6* range or so. Also the 2 piece shaft isnt an issue, just the FAD housing so stock no reason to delete it, but i'd for sure truss it.

If you go aftermarket then thats not a concern
 

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Artsifrtsi

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I'd be more apt to delete it if I were to change out the whole housing, see more issues with housing at the FAD breaking than the actual FAD tapping out.
 

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I say keep it and if you're really worried about it, truss the axle tubes and end forgings while you have the axle housing out. I think RCV makes axles that work with the FAD. As other have said, the FAD works well, the FAD housing is the issue.
 

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I prefer to keep the FAD and truss the housing, but I'm not a hardcore wheeler with this truck.

I have to deal with my YJ front driveline vibration because I swapped in the Rubi D44 TJ housing without the FAD and it would be super annoying on the longer trips we take in the JT should the same issue arise.
 
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JTenn

JTenn

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Great replies and much thanks. Y'all have opened my eyes and changed the direction I was leaning. I don't wheel this truck hard core, and 95% of its life is on the road so i dont want to deal with driveline vibration. I will keep the FAD when I upgrade to the RCV shafts. If it ain't broke don't fix it. Great advice, thanks.
 

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Great replies and much thanks. Y'all have opened my eyes and changed the direction I was leaning. I don't wheel this truck hard core, and 95% of its life is on the road so i dont want to deal with driveline vibration. I will keep the FAD when I upgrade to the RCV shafts. If it ain't broke don't fix it. Great advice, thanks.
For what itā€™s worth, I kept my FAD and have RCV shafts with the FAD. Iā€™ve had zero problems with hardcore trails. Iā€™m keeping it and like how it functions.
 

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Other than saving a quarter mile per gallon with a tailwind down hill I don't see any other advantage to it. Weakest spot in the axle.
That's about what was discovered by a small car company in the 1980s. And thus, they got rid of it in their cars in 1984. It wasn't worth the cost/expense.
Today they do it because of fleet numbers being so strict.
Plus there is a wear factor on the front differential........
You do have more drag because you are spinning the whole differential carrier and putting reverse wear on the pinion and ring gear, but without load, negligible, I suspect.
Without the FAD, you are spinning the carrier all the time, and reverse load on the front ring gear and pinion - spinning the front drive shaft all the time.
 
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JTenn

JTenn

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For what itā€™s worth, I kept my FAD and have RCV shafts with the FAD. Iā€™ve had zero problems with hardcore trails. Iā€™m keeping it and like how it functions.
Good to know. Thanks for letting me know that.
 

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Great replies and much thanks. Y'all have opened my eyes and changed the direction I was leaning. I don't wheel this truck hard core, and 95% of its life is on the road so i dont want to deal with driveline vibration. I will keep the FAD when I upgrade to the RCV shafts. If it ain't broke don't fix it. Great advice, thanks.
If you donā€™t wheel hard core, the stock shafts are fairly sufficient. What size tires will you be running?
 

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JTenn

JTenn

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If you donā€™t wheel hard core, the stock shafts are fairly sufficient. What size tires will you be running?
I have 35's. But I just bought a set of Rubicon axles with 5.13 gears. I'm just wanting to build them up a little before I install them. With the 5.13's I can easily go up to 37's if I want but I wouldn't ever go bigger than that.
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