4A was available before the X models came out as an option pre 2023. Those models had a functioning FAD that engaged in 4A as well as 4H and 4L but was open in 2H.
That design wasn't successful because the air actuators and lines failed regularly and were difficult to field repair not because the spider gears turning with no load? The current fad uses a much more reliable electric motor to accuate. The JLs have been running them since 2018 and failures are still rare. If you wheel like the youtubers always in 4wd the second you touch dirt then locking hubs would be fine. My JT probably has 1000x more dirt miles in 2wd than 4wd because you rarely need it in the desert, but when you do it's a simple pull of the lever. Then it goes back to 2H as it just handles better at speed that way.
I agree with the 1st part, I like shift on the fly especially in changing terrain. Sure you can lock in the hubs and still shift into 2wd, but we do a lot of freeway speed driving in the desert and I wouldn't want the extra wear. I like the FAD enough I'd add it to a new Jeep if I bought one that only came with the block off plate (392s, 4A, etc).
I have a 2022 Rubicon. 4 auto and FAD.
When the hubs are open. For my use I'm in and out of 4wd a dozen times out in the desert. Certainly not stopping and locking/ unlocking hubs that often and I don't want to put hundreds of miles on it with the hubs in in 2wd. Also the tire doesn't spin when you blow up a hub (which I've done a couple times). When the old air actuator would fail you could pop the 4 bolts off the cover and shift the thing manually. Wedge a stick in there and put the cover back and you're in business. I'd imagine the same could be done with the FAD.
Interesting.
Personally I have 0 interest in putting wear items (clutches) inside the transfer case and have no problem shifting into 4wd when needed so I intentionally avoided the 4A models when shopping for both the wife's JLUR and my JT. If I lived somewhere where ice and snow where constant for months I could see the use, but even there I prefer 4wd to work when I want it to and don't mind shifting.
When I bought mine, there wasn't much information on them. If I could turn back time, I'd go with a normal Rubicon 4:1. I have had no issues with mine. But, I try and keep the fluid changed in it, and I drive in 2wd 90% of the time. The 392 folks don't have that luxury.
The 392 rips the 4A transfer case out if put to the real test. That's one of the main reasons alot of them are going to an Atlas the clutches cant take the heat in the 4A.
I have a 2024 Mojave X…..
Just crawled underneath to take a photo… If that’s not a FAD, then what’s in the box?
Adding caster decreases pinion angle, so I wouldn't say high caster results in a severe pinion angle with our axles. It actually results in low pinion angle.
THanks!! Interesting.... So, obviously the shaft is splined and runs thru that - and acts as a 'support'?? I can imagine those forks wearing away rather quickly.This is what is behind that plate.
