Advanced 4x4 automatic on demand engagement price?

[Austin26]

My word is as good as gold.



$$$. Most people wouldn't actually use a locker or a limited slip. If automakers can repurpose the ABS and traction control modules that they already have to put in the car to give you some fraction of the capability at basically zero cost, they'll do that first.



The issue is that it's a reactive system. A wheel has to slip first, then the system pulses the brakes, then it transfers some small amount of power momentarily, then repeats until you're either unstuck or hopelessly stuck.

In conditions like loose dirt and sand where momentum is important, a locker or LSD is the best way to maintain momentum. WIth an open diff, one wheel has to start slipping, which means one wheel is digging instead of pushing you forward.



Yes, without 4A, it's in 2wd until you manually switch to 4. It's how most trucks have worked for most of history. Only in the last decade or two have they started putting automatic 4x4 into trucks. Jeep has had a few variations on automatic 4x4 over the years ("Selec-Trac," "Quadra-Trac," etc.).

Thank you for your help. Unfortunately much of what I'll do will be on sand so I have some decisions to be made.

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[Eggsalad]

Advanced 4x4 ("4A") will actively transmit power rear to front when the rear slips. This is useful for on-road driving in bad weather when you don't want to constantly switch between 4H and 2H. For instance, it snowed a couple of inches last night here in Iowa and depending on what road I was on, there was a little slush, a little snow, or totally dry. If I wanted to maximize traction without 4A, I would have been switching back and forth between 4H and 2H several times during the drive, since I would need 4H in the slush and snow, but 4H would bind up trying to turn on dry pavement so 2H is necessary there. 4A lets you leave it in 4A and it will transmit power to the front when it needs to, but leave the front disconnected during sharp turns and at steady speeds when you don't need traction up front. You wouldn't use 4A while offroading.

What you were seeing on the Jeep is normal traction control, every Bronco will have that. It uses the brakes to reactively move power around side to side because you didn't want to upgrade to a locker.

That's a good example of 4A usage. 4A is also fine offroading as you go through various surfaces. It's a good thing to have in any trim and seems to be a reasonable price.

 

[Mattwings]

There has been lots of discussion on various threads and still a lot of misunderstanding. This article was pretty good at explaining and evaluating it. Same case as the Raptor and upcoming F150 Tremor. I have had both systems and I can get by with the standard case, but at the price, it’s a no brained option IMO.
https://www.truckcamperadventure.com/ford-raptor-features-new-cutting-edge-transfer-case/

 

[loginhere]

for the price, it seems great, but it also changes rear axle ratio, meaning its going to cost gas mileage as well. im not sure why they have to upgrade to a higher rear axle ratio to add auto on demand

 

[stueyd]

The bp shows auto 4x4 as a no- cost option for Black Diamond manual transmission. Is that correct or a bug? All lesser models make this avail only with automatic transmission.

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