2024 Mojave front axle and transfer case- How it works?

[StarsMojave]

I’ve been reading about the 2024 Mojave OEM FAD delete on the front axle. From the information I have gathered I can’t really understand how this 4wd mechanism works. The mention of the 392 transfer case comes up. Can anyone explain how all this works or point to a link that explains how all this works.

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[Badunit]

The front axle shaft on the passenger side is two pieces. One connects to the differential, the other to the wheel. They butt end-to end, they are both splined, and a splined collar slides over them to connect/disconnect them. That is the FAD.



I have read that the Wrangler 392 does not have a FAD and it is always in 4wd. I've not seen one in person and have no intention of buying one so that's about all I know (or think I know).

 

[jac04]

It sounds like you asking how the Selec-Trac system works.

If so ... Selec-Trac, with the transfer case selector in 4H AUTO, uses a variable clutch system to vary the amount of power sent to the front based on a lot of factors including detected slip. In 4H AUTO, the variable clutch system allows the front & rear driveshafts to turn at different speeds, acting like a center differential. It is essentially an all-wheel-drive system when in 4H AUTO, allowing you to drive in all types of conditions, from dry pavement to super slippery conditions.

When the transfer case is in 4H Part-Time or 4L, Selec-Trac still uses the variable clutch system, but at 100% clutch engagement to force the front & rear driveshafts to turn at the same speed all the time. This should only be used in very low traction situations.

 

[Erievon]

Possibly obvious but I'll say it anyway. In 4 Auto, the FAD stays locked and ready for the selec trac to send torque to the front at any moment. It only unlocks in 2H.

Also suggest you only use 4 auto when traction is sketchy and variable (snow, maybe rain). Remember to do what it does, the clutches in the transfer case have to slip. Slip = wear, and is likely why you are seeing problems in the 392, because you can't put it in 2H.

If you're in the dry and traction is fine, use 2h, clutches will not slip at all and fad unlocks. If you are offroad in dirt or sand and can use 4H or 4L do it, clutches will lock to 100% and not slip. Let the tires take the abuse. Use 4 Auto for inbetween sketchy stuff only.

People that leave it in 4Auto 24/7/365 or are forced to do so like a 392, are the ones that will say this transfer case is a problem.

 

[StarsMojave]

It sounds like you asking how the Selec-Trac system works.

If so ... Selec-Trac, with the transfer case selector in 4H AUTO, uses a variable clutch system to vary the amount of power sent to the front based on a lot of factors including detected slip. In 4H AUTO, the variable clutch system allows the front & rear driveshafts to turn at different speeds, acting like a center differential. It is essentially an all-wheel-drive system when in 4H AUTO, allowing you to drive in all types of conditions, from dry pavement to super slippery conditions.

When the transfer case is in 4H Part-Time or 4L, Selec-Trac still uses the variable clutch system, but at 100% clutch engagement to force the front & rear driveshafts to turn at the same speed all the time. This should only be used in very low traction situations.

According to my window sticker my Mojave has Command-Trac Part Time 4WD System though if I look at the FAD on the front axle there is no electrical connection to the FAD suggesting that it is a delete and just has a cover plate. So with this system where is the 4WD system engaged and what is now functioning in place of the FAD? Thanks

 

[Erievon]

According to my window sticker my Mojave has Command-Trac Part Time 4WD System though if I look at the FAD on the front axle there is no electrical connection to the FAD suggesting that it is a delete and just has a cover plate. So with this system where is the 4WD system engaged and what is now functioning in place of the FAD? Thanks

If you have the fad factory delete the front axle is always connected to the Dif. And then with command trac part time, the transfer case only sends power to the front dif when in 4h or 4l.

Little worse on MPG but more reliable that way.

 

[StarsMojave]

If you have the fad factory delete the front axle is always connected to the Dif. And then with command trac part time, the transfer case only sends power to the front dif when in 4h or 4l.

Little worse on MPG but more reliable that way.

So Command-Trac is similar to what is in my 2015 JK, just a simple lever engaged 4WD system? No clutch packs to worry about that the 392 uses which is the Select-Trac system?

Since my FAD is considered delete is there just a straight axle from diff to wheel on that side and not the two axle splined/collar assembly?

So then how does the Off-Road Plus Mode work?

Sorry for all the questions but all this hopefully is making sense. Thank you!

 

[Zachanadandy]

The factory FAD delete is just a cover with the shift fork welded in place. Still a 2 piece shaft with the coupler. If you really wanted a functioning fad you could buy a fad motor assembly and wire it to a 12v switch. That said you won't gain much. The only real difference is your front driveshaft now turns when the wheels are rolling on the ground. Transfer case functions the same either way. 2wd disengages the front output. 4wd+ also functions the same with or without a FAD. In 4HI it raises shift points so you hold gears longer and have better throttle response due to the higher rpms. In 4LO it decreases throttle sensitivity for more control when crawling.

 

[PuddleJumper]

According to my window sticker my Mojave has Command-Trac Part Time 4WD System though if I look at the FAD on the front axle there is no electrical connection to the FAD suggesting that it is a delete and just has a cover plate. So with this system where is the 4WD system engaged and what is now functioning in place of the FAD? Thanks

Yes the FAD is not existent on select trac jeep. Not sure what year they started tho as my rubicon is selec trac but still has the FAD. Essentially 2wd drive on your truck won't send power to the front drive shaft but it will still spin as the front is still locked up. Pretty much like driving an old truck with the hubs locked but in 2wd. cost you a little mpg but other than its fine.

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