392 D44 axles, where's the beef

[beckbuilt]

I just installed a 392 front axle into a JLU Sahara. The front pinion flange is thicker with a recessed thread, so you'll need the longer front yolk bolts from a 392. The front drive line worked great. It still has a good amount of compression at full bump.

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[NyRey87]

I just installed a 392 front axle into a JLU Sahara. The front pinion flange is thicker with a recessed thread, so you'll need the longer front yolk bolts from a 392. The front drive line worked great. It still has a good amount of compression at full bump.

Thank you!

 

[J0E]

Seem like the FAD housing in the passenger side axle tube is still a weak link for 37" and larger tires. Fortunately, I have pin pointed my JLR's use to 5 rated trails. IMHO, on my JLR bigger isn't better for daily drivering and middle rated trails. I'm now on 35's and liking them to date.

FAD is the weak link but tire size has virtually nothing to do with breaking the axle at the FAD. That's the impulse on the axle due to the mass * velocity. It's not like the drive line where T = R cross F, where there's a direct connection to the tire radius. The increase in mass of the bigger tires is inconsequential compared to the mass of the vehicle.

OEM Rubicon axles work fine also IMHO.

If you're easy on the skinny petal.

The few mm of increased tube thickness don't add much strength. It's the tube diameter that matters. Tube strength goes up as the fourth power, and it is called Moment of Inertia, or Inertial Stiffness. JL vs JK:

3.14159265 × (D4 - d4) ÷ 64
(70^4 - 63.65^4) ÷ (62.5^4 - 56.15^4) × 100% = +43% stiffer (JL axle)

 

[NyRey87]

Axles installed
Regeared to 4.88
Lasfit switches installed
This thing is a rocket ship, need to turn the pedal commander to eco mode!

 

[patreesheo]

Axles installed
Regeared to 4.88
Lasfit switches installed
This thing is a rocket ship, need to turn the pedal commander to eco mode!

Nice!! Looking to pick up a set of 392's for my 2018 jlus. A few questions.. The tazer will fix the gears and lockers. What did you do to remove the serv 4wd? My PLAN is that I will remove the fad solenoid out of my sport axle, plug it back into the connector to the transfer case wiring, wrap it up and tuck it away somewhere? Anything else I may be obviously missing?

 

[NyRey87]

Nice!! Looking to pick up a set of 392's for my 2018 jlus. A few questions.. The tazer will fix the gears and lockers. What did you do to remove the serv 4wd? My PLAN is that I will remove the fad solenoid out of my sport axle, plug it back into the connector to the transfer case wiring, wrap it up and tuck it away somewhere? Anything else I may be obviously missing?

The Tazer did allow me to adjust all those parameters, although when I had them installed I had the Lasfit switch bank installed at the same time as well as having them regeared to 4.88. The only thing we ran into was needing longer bolts for where the axle meet the driveshaft, I think the flange was longer or larger on the 392 axle. Other than that it was a pretty straightforward swap.

As far as the FAD goes they left it off when we swapped to the 392’s. And I’m not sure about the serv 4wd. Hopefully that helps you out, the only other thing of note was as far as I’ve gathered it’s almost impossible to use the factory locker switches from a Rubicon on a Sport, I can’t find anyone who was able to do it and I didn’t have the time or money to try to get it to work so I went with an aftermarket option in Lasfit.
If you’ve any other questions I’d be happy to try to help.

 

[1996cc]

Nice!! Looking to pick up a set of 392's for my 2018 jlus. A few questions.. The tazer will fix the gears and lockers. What did you do to remove the serv 4wd? My PLAN is that I will remove the fad solenoid out of my sport axle, plug it back into the connector to the transfer case wiring, wrap it up and tuck it away somewhere? Anything else I may be obviously missing?

you just use a Tazer and set it to no FAD. No need for the solenoid, just wrap up the wiring and call it good.

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