Needed: 4x4 Option Explanation

firefox33

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The following is from my OB build.
Sorry if this has been asked and explained previously. I‘m not sure I understand the difference. If someone has a good understanding and the patients to explain it, I would appreciate your comments. Thanks.
3523B7AC-FC94-4BC3-AB90-660031C4F861.png





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rtaylor

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The following is from my OB build.
Sorry if this has been asked and explained previously. I‘m not sure I understand the difference. If someone has a good understanding and the patients to explain it, I would appreciate your comments. Thanks.
3523B7AC-FC94-4BC3-AB90-660031C4F861.png
2 advantages to automatic transfer case:

1) can be set to automatic mode (4A) on all surfaces, including dry pavement. similar operation to all wheel drive in that mode.
2) has lower gear ratio for 4L
 

Garye

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2 advantages to automatic transfer case:

1) can be set to automatic mode (4A) on all surfaces, including dry pavement. similar operation to all wheel drive in that mode.
2) has lower gear ratio for 4L
So does this mean if I go with Part Time Selectable when I put it into 4H it will be the same as 4A but I did it manually
 

rtaylor

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So does this mean if I go with Part Time Selectable when I put it into 4H it will be the same as 4A but I did it manually
No, it offers more than you can accomplish manually. If you are are on snow pack or muddy road you would still put it in 4H to lock it in 4wd mode. 4A can be enabled anytime you want (on dry, wet, patchy slick, or dirt road) and the electric clutch pack will be automatically controlled to quickly split torque as needed. In 4A mode the clutch pack works similar to a center differential (all wheel drive). It can be left in 4A all the time if you want improved traction in all circumstances, including dry road.
 

Lakelife36

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So does this mean if I go with Part Time Selectable when I put it into 4H it will be the same as 4A but I did it manually
Nope they each have a selectable 2H, 4H, and 4L mode. The added 4A mode in the advanced 4x4 allows it to transfer power between the two axles without it being in the traditional 4H mode. This is done with electromagnetic clutches either on a centre diff or in the transfer case itself, I'm not sure which. Think of it like an AWD system, so it's safe to drive on dry asphalt. I also like the idea of being able to make really tight turns in sketchy spots while still getting power to both axles.
 

ac360

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Traditionally you select 2H, 4H, & 4L manually.
With 4A, the vehicle defaults to running in 2H, but will automatically shuffles between 2H & 4H depending on road conditions to give best traction. In theory, you can leave it in 4A and forget, but you'll pay a small mpg penalty.
 

grimmjeeper

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The biggest thing with the manual transfer case is that you shouldn't run in 4WD on paved roads.

The manual transfer case locks the front and rear driveshaft together so they always spin at the same speed. But when you go around a corner, the front tires travel a further distance than the rear tires so the front driveshaft wants to turn faster than the rear driveshaft. That creates a lot of stress on the driveshafts, the transfer case, the axle shafts, the CV joints, etc. That shortens the life of everything.

4WD is fine on dirt roads or other "low traction" surfaces like mud, snow, and ice. What happens is that the tires are able to slide much easier, relieving the stress on the rest of the system. And when you're stuck in the mud, putting it in 4WD will direct power from the engine to the tires that have better traction and let you get unstuck.


The automatic system is different. The transfer case has a differential inside that lets the two driveshafts spin at different speeds. So when you're on dry roads, you can go around a corner without the added stress. In that way, it works like the all wheel drive like you find in a Subaru or many other vehicles.

The added computer control uses the wheel speed sensors to detect when wheels start to slip. The transfer case has some electronic controls that let the computer "firm up" and even lock the differential so that power goes out equally to the front and rear (along with using the ABS braking system to put the brakes on just the one spinning tire). So as you drive down the road, the computer is able to adjust very quickly to changing conditions and get the power to the wheels that grip, all without you having to do anything.


Which one you want is up to you.

The manual 4WD system is a time tested system that does things the way they've been doing things for a very long time. It works. But it does have some limitations and requires knowing the system and when to pick one mode over the other.

While early computer controlled 4WD systems left a lot to be desired, the modern systems have gotten a lot better. I haven't seen the GOAT modes in action but I expect that they will do pretty well given the intent of the new Bronco and the engineering hours that went into building it.

If you primarily drive on road and rarely get beyond a poorly maintained dirt road, the automatic 4WD system is probably the best. It will give you the best all around behavior without having to think about it too much. Just select the conditions on the dial and go. Even if you start taking bigger and harder trails I suspect the GOAT modes will do pretty well and I look forward to seeing just what they're capable of.

If you just like having the manual system, go for it. Nothing wrong with it.
 

Garye

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The biggest thing with the manual transfer case is that you shouldn't run in 4WD on paved roads.

The manual transfer case locks the front and rear driveshaft together so they always spin at the same speed. But when you go around a corner, the front tires travel a further distance than the rear tires so the front driveshaft wants to turn faster than the rear driveshaft. That creates a lot of stress on the driveshafts, the transfer case, the axle shafts, the CV joints, etc. That shortens the life of everything.

4WD is fine on dirt roads or other "low traction" surfaces like mud, snow, and ice. What happens is that the tires are able to slide much easier, relieving the stress on the rest of the system. And when you're stuck in the mud, putting it in 4WD will direct power from the engine to the tires that have better traction and let you get unstuck.


The automatic system is different. The transfer case has a differential inside that lets the two driveshafts spin at different speeds. So when you're on dry roads, you can go around a corner without the added stress. In that way, it works like the all wheel drive like you find in a Subaru or many other vehicles.

The added computer control uses the wheel speed sensors to detect when wheels start to slip. The transfer case has some electronic controls that let the computer "firm up" and even lock the differential so that power goes out equally to the front and rear (along with using the ABS braking system to put the brakes on just the one spinning tire). So as you drive down the road, the computer is able to adjust very quickly to changing conditions and get the power to the wheels that grip, all without you having to do anything.


Which one you want is up to you.

The manual 4WD system is a time tested system that does things the way they've been doing things for a very long time. It works. But it does have some limitations and requires knowing the system and when to pick one mode over the other.

While early computer controlled 4WD systems left a lot to be desired, the modern systems have gotten a lot better. I haven't seen the GOAT modes in action but I expect that they will do pretty well given the intent of the new Bronco and the engineering hours that went into building it.

If you primarily drive on road and rarely get beyond a poorly maintained dirt road, the automatic 4WD system is probably the best. It will give you the best all around behavior without having to think about it too much. Just select the conditions on the dial and go. Even if you start taking bigger and harder trails I suspect the GOAT modes will do pretty well and I look forward to seeing just what they're capable of.

If you just like having the manual system, go for it. Nothing wrong with it.
 

Garye

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Thank you guys for your answers. It’s funny you used a Subaru comparison because that’s what my wife drives and I like that when we have slippery icy conditions here in So Oregon the AWD is nice feature. Me on the other hand have an older 4WD Tundra. I’m pretty much stuck with 2WD because if I stick it into 4H I get the hopping of the front end during turns. Due to the excellent advice you guys have given me on the differences between the two I am going to go with the automatic system.
 

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Thank you guys for your answers. It’s funny you used a Subaru comparison because that’s what my wife drives and I like that when we have slippery icy conditions here in So Oregon the AWD is nice feature. Me on the other hand have an older 4WD Tundra. I’m pretty much stuck with 2WD because if I stick it into 4H I get the hopping of the front end during turns. Due to the excellent advice you guys have given me on the differences between the two I am going to go with the automatic system.
Yeah, I daily drive a Subaru here in the Denver area. It's a great system for getting around in the snow and ice but still drives like a normal car when it's clear and dry. I like not having to think about it at all.

My old Cherokee has a more traditional transfer case but it's the NP242 that adds an extra "full time" 4WD option. So I shift between 2wd/part time 4hi/full time 4hi/neutral/4low. I love the addition of the "full time" feature. It has the differential that lets me drive in mixed snow/ice conditions and not have to shift out of 4WD when I hit dry patches. The TrueTrac differentials I added to the axles front and rear really are great for all around bad weather driving. The thing is a monster in the snow.

When I replace those two vehicles with just one (leaning towards a new Bronco) I'll get the auto 4WD system.
 
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firefox33

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Thank you all for your comments and sorry if it was a nagging repeat question for some of you.
 

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