So 4A is not what I had thought...

[ChrisE]

I was running 2wd and noticed excessive tire wear in the rear (all my other rwd cars wear more even) and switched ton 4A to even wear more between rotations but noticed a hum when cruising. It does appear something is engaged full time and the hum, while maybe no issues long term with wear or fuel economy, was annoying so I went back to 2wd. Thing is noisy enough, don't need more

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[lakesinai]

Over the last couple years there has been several discussions about 4A, along with all the "rules" about using 4x4 in high traction environments (like the street).

I've even contributed to multiple threats about 4A where the thought process was that it's in two-wheel drive unless it's senses slippage and then it kicks into 4 wheel drive.

This is not the case and Ford has seemed to have reinvented physics

All of us that have SPORT mode know that 4A engages with this GOAT and it is specifically designed for the street. Now that goes against the "No 4x4 on street" rule. However with the mentality that the 4A/4H doesn't kick in until it needs to, it should not be an issue.

Well I've been playing around with 4A and watching the "power distribution" and a bunch of us, including myself, we're wrong with our assumptions.

4A basically has the vehicle in 4x4 mode pretty much the entire time. There are some inconsistencies, but the only time that I've seen it NOT applying power to all wheels is when off the throttle, or I think, if you have the steering significantly turned BEFORE applying throttle.

To give you some examples, going 75 mph down the freeway and giving it some throttle = 4 wheel drive

Throttling while going through twisty turns on a mountain road = 4 wheel drive.

To me the scariest.... Doing a U-turn at a light (which requires throttle) = 4 wheel drive.

Like I said, there have been a couple of situations when I was testing, and if I turn the steering wheel significantly Before applying the throttle, it seems = 2 wheel drive.

I don't get me wrong, I love the feel of basically AWD... It's been storming (rain) all week where I live, and in 4A, the Bronco has been planted and not a single wheel slip.

I just hope Ford design this correctly and taking windy roads in sports mode isn't going to break something.

I drive in 4A full time, and I had assumed its in 2wd unless it needs 3 or 4 wheels, but how to measure that? It's my understanding that the Advanced Transfer Case would allow (apply) slippage to whatever wheels would otherwise bind, and apply power as needed so that there is not the crabbing that occurs when we select 4H on pavement. And there is no crabbing in hard turns on pavement when I'm in 4A, which seems to contradict your findings? This is similar to a Subaru, which claims it is always sending power to all 4 wheels, but it can vary that power. if I understand correctly, Subary has 4 viscous "clutches" closer to the wheels that apply slippage or power as needed. The clutches are pricey, I've had them replaced.

 

[Rjacks258]

Still going…….nobody outlasts the, er a, endless pointless threads.

 

[Laminar]

Another 4A thread, no new information, but plenty of the same misinformation being shared over and over.

You are misreading the displays for sure. 4A is in fact just like any other all wheel drive vehicle like my X4 rear wheel drive always and only engages front when slippage occurs. These are not intelligent like Subaru or Honda.

Nope. Pull up Forscan and watch the transfer case modulation in 4A. Leaving from a stop, it ramps the front axle in even with 0 slip.

Interesting read, big thing is programming. I don't think any of us know how aggressive Ford was with the programming.

See above. Based on throttle position, speed, and steering angle you can see exactly how aggressive the programming is.

The Bronco sport has 2 clutch’s on the rear wheels in addition to the center clutch that allows torque vectoring side to side. Imho the bronco sport has one of the most capable AWD systems around.

In theory, maybe, but Throttle House showed that the rear "diff lock" doesn't actually lock anything, which is disappointing. It may be among the better pedestrian crossover AWD systems, but it still wouldn't compare to the off-road capability of true lockable differentials or the on-road potential of a true performance 4-wheel torque-vectoring AWD system. It's fine for pulling away from stop signs in snowy weather, though.

 

[Rjacks258]

Can we lock it now?

 

[BigMeatsBronco]

This is from the Ford workshop manual, explaining each operation. Follow these and perform diligent maintenance and everything will be fine.

No need to guess what does what unless that makes you feel better. j/k

Enjoy! and Happy New Year!


(2H) OPERATION

When the ATCM is in (2H), power is delivered to the rear wheels only. This mode is appropriate for normal on-road driving on dry pavement and provides the best fuel economy. Torque is passed through the transfer case to the rear driveshaft at a 1:1 ratio. In (2H):

• The ATCM sends a (2H) mode status to the AWD module via the GWM .
• The transfer case clutch is at or below the kiss point.
• The reduction sleeve connects the input shaft and output shaft
• (2H) will momentarily be displayed in the message center at key up and after a 4WD to (2H) shift.

(4A) OPERATION

When (4A) is selected on the ATCM , the 4WD system provides electronically controlled four-wheel drive with power delivered to all four wheels, as required, for increased traction. (4A) is appropriate for all on-road driving conditions, such as dry road surfaces, wet pavement, light snow or gravel. Shifts from (2H) or (4H) to (4A) can be made at any speed. In (4A):

• The ATCM sends a (4A) mode status to the AWD module via the GWM .
• The shift motor positions the ball ramp device at the clutch kiss point when driving conditions do not require 4WD.
• The shift motor positions the ball ramp device to apply the clutch when wheel slip is anticipated or detected.
• The reduction sleeve connects the input shaft and output shaft
• (4A) is displayed in the message center.

AUTOLOCK

If the system is in (4A) and AWD module detects driving conditions that require greater 4WD performance, the AWD module temporarily turns on (4H). The message center displays 4X4 TEMPORARILY LOCKED. The 4WD system automatically returns to (4A) after the system no longer detects these driving conditions. The message center will temporarily display 4X4 RESTORED.

POWERTRAIN TORQUE PROTECTION

If the system is in (4A) and AWD module detects excessive stress or high energy going through the clutch (clutch is slipping excessively while the system is commanding max clutch torque), the shift motor will release the clutch and message center indicates 4x4 TEMPORARILY DISABLED. When the system had the ability to cool off, 4x4 operation will be automatically restored. The message center will temporarily display 4X4 RESTORED.

(4H) OPERATION

(4H) provides electronically locked four-wheel drive power to both the front and rear wheels for use in off-road or winter conditions such as deep snow, sand or mud. This mode is not for use on dry pavement. Shifts from (2H) to (4H) can be made at any speed. In (4H):

• The ATCM sends a (4H) mode status to the AWD module via the GWM .
• The shift motor positions the ball ramp device to completely apply the clutch.
• The reduction sleeve connects the input shaft and output shaft
• (4H) is displayed in the message center.

(4L) OPERATION

(4L) provides electronically locked four-wheel drive power to both the front and rear wheels for use on low traction surfaces but does so with an additional gear reduction for increased torque multiplication. Intended only for off-road applications such as deep sand, steep grades or pulling heavy objects. (4L) does not engage when your vehicle is moving above 3 mph (5 km/h); this is normal and should be no reason for concern.

Shifts to and from (4L) can only be made below 3.1 mph (5 km/h) with the transmission in Neutral. When performing this shift, wait until the 4x4 Shift in Progress message disappears in the IPC before moving the selector lever back to Drive. If the vehicle speed or transmission range is not within parameters, the message center will indicate the necessary action needed to complete the shift. In (4L):

• The ATCM sends a (4L) mode status to the AWD module via the GWM .
• The shift motor positions the ball ramp device to completely apply the clutch.
• The shift motor positions the reduction sleeve connecting the planetary carrier and output shaft
• (4L) is displayed in the message center.

NEUTRAL OPERATION

For recreational towing (all 4 wheels on the ground) the transfer case should be placed in Neutral.
Refer to: Neutral Flat Tow Activation and Deactivation (307-07B Four-Wheel Drive Systems - Advanced 4x4 with 4A Mode, General Procedures).

• The IPC sends a Neutral mode status to the AWD module via the GWM .
• The shift motor positions the ball ramp device to completely apply the clutch.
• The shift motor positions the reduction sleeve to only engage the output shaft
• “Neutral Tow Enabled” is displayed in the message center.

G.O.A.T. Modes

NOTE: Not all G.O.A.T. modes are available in each trim level.

The vehicle is equipped with Goes Over Any-type of Terrain (G.O.A.T.) Modes that allows the driver to enhance the off-road performance of the vehicle by selecting the mode best suited to the terrain and driving conditions. Each mode changes a number of the vehicle parameters within the engine, transmission, traction control and 4WD systems.

Normal

• For everyday driving. This mode is the perfect balance of excitement, comfort and convenience. This is the default mode after each ignition cycle, the driveline settings remain the same prior to the ignition cycle.
• (2H) is the default four-wheel drive mode. All four-wheel drive modes are selectable when in normal mode.
• The front electronic locking differential, if equipped is available when in (4L).
• The rear electronic locking differential, if equipped is available.
• The stabilizer bar disconnect is available if (4H) or (4L) is selected.

Eco

• For efficient driving. This mode helps deliver maximum fuel efficiency and helps to increase driving range.
• (2H) is the default four-wheel drive mode. (4L) is not selectable in eco mode.
• The front electronic locking differential is not available in eco mode.
• The rear electronic locking differential is available.
• The stabilizer bar disconnect is not available in eco mode.

Sport

• For sporty driving with improved performance handling and response. This mode increases accelerator pedal response and provides a sportier steering feel. The powertrain system holds onto lower gears longer, helping your vehicle accelerate faster.
• (2H) is the default four-wheel drive mode. (4L) is not selectable in sport mode.
• The front electronic locking differential is not available in sport mode.
• The rear electronic locking differential is available.
• The stabilizer bar disconnect is not available in sport mode.

Slippery

• For less than ideal road conditions such as snow or ice covered roads. This mode can be used for crossing terrain where a firm surface is covered with loose, wet or slippery material. Slippery mode lowers throttle response and optimizes shifting for slippery surfaces.
• (4H) is the default four-wheel drive mode. Both four-wheel drive modes are selectable in slippery mode.
• The front electronic locking differential is available when in (4L).
• The rear electronic locking differential is available.
• The stabilizer bar disconnect is not available in slippery mode.

Sand

• For off-road driving on soft, dry sand or deep snow. This mode may help get your vehicle unstuck from deep snow or sand.
• (4H) is the default four-wheel drive mode. (4L) is selectable in sand mode.
• The front electronic locking differential is available when in (4L).
• The rear electronic locking differential is engaged when in sand mode and is available in all selectable four-wheel drive modes.
• The stabilizer bar disconnect is available in (4H) or (4L).

Mud/Ruts

• For off-road driving. This mode enhances vehicle performance to traverse muddy, rutted or uneven terrains.
• (4H) is the default four-wheel drive mode. (4L) is selectable in mud/rut mode.
• The front electronic locking differential is available when in four-wheel drive low.
• The rear electronic locking differential is engaged when in mud/ruts mode.
• The stabilizer bar disconnect is available in (4H) or (4L).

Rock Crawl

• For off-road driving and optimum rock-climbing ability. Rock crawl mode optimizes the throttle and transmission response to provide you additional control of your vehicle.
• (4L) is the only four-wheel drive mode selectable in rock crawl, the system prompts you to put your vehicle into (4L) upon selection.
• The front electronic locking differential is available when in (4L).
• The rear electronic locking differential is engaged when in rock crawl mode.
• The stabilizer bar disconnects when in rock crawl mode.

Baja

• For high speed off-road driving. Baja mode optimizes the throttle control for better response and torque delivery.
• (4H) is the default four-wheel drive mode.
• The front electronic locking differential is available when in (4L).
• The rear electronic locking differential is available
• The stabilizer bar disconnect is available in (4H) or (4L).

Here's a picture of the ball ramps and wet clutches mentioned above in The manual...hope this helps folks understanding

 

[Bmadda]

4A is what I thought!?!

 

[Kramku1]

4A is not as smooth as 2wd and so far I have gotten around great in snow in 2wd, bronco's are fun and capable nothing compares IMHO

 

[da_jokker]

Still going…….nobody outlasts the, er a, endless pointless threads.

You know it's a funny thing, don't actually have to read threads that you're not interested in.

Move along, these aren't the droids you're looking for.

 

[da_jokker]

For all of you that are complaining about this being another 4A thread, to be clear this thread is about how Ford says it's okay for 4A in sports mode but not okay 4A in slippery mode.

 

[Ducati1098]

Ford says it's okay for 4A in sports mode but not okay 4A in slippery mode.

I think you’re misunderstanding what they wrote. It does not say that anywhere in the owners manual.

All it does is give a generic warning that depending on what 4 wheel drive mode you’re in, you could experience vibration, driveline bind up, damage and potential excessive tire and vehicle wear.
No where does it say 4A specifically will do this.

 

[da_jokker]

I think you’re misunderstanding what they wrote. It does not say that anywhere in the owners manual.

All it does is give a generic warning that depending on what 4 wheel drive mode you’re in, you could experience vibration, driveline bind up, damage and potential excessive tire and vehicle wear.
No where does it say 4A specifically will do this.

I specifically looked under this section for 4A and it clearly says damage and is refering to all those things that we know are the reasons as to why you don't run in 4x4 mode normally.

In addition, under the sports mode section for 4A...it does NOT have this warning.

..thus my post.... I found it very odd and inconsistent.

SLIPPERY - ADVANCED 4X4 WITH
4A MODE

For less than ideal road
conditions, this mode can be
used for crossing terrain where
a firm surface is covered with loose or
slippery material, such as snow or ice....

Note: When using Slippery mode on
dry/hard pavement, your vehicle could
experience vibration, driveline bind up,
damage and potential excessive tire and
vehicle wear.

 

[Ducati1098]

I specifically looked under this section for 4A and it clearly says damage and is refering to all those things that we know are the reasons as to why you don't run in 4x4 mode normally.

In addition, under the sports mode section for 4A...it does NOT have this warning.

..thus my post.... I found it very odd and inconsistent.

SLIPPERY - ADVANCED 4X4 WITH
4A MODE

For less than ideal road
conditions, this mode can be
used for crossing terrain where
a firm surface is covered with loose or
slippery material, such as snow or ice....

Note: When using Slippery mode on
dry/hard pavement, your vehicle could
experience vibration, driveline bind up,
damage and potential excessive tire and
vehicle wear.

Maybe you’re reading that in an outdated version of the owners manual. Either way, it does not say that anywhere in the newest version available. Here is what it shows:

Edit: Although even this is still slightly inaccurate, because if I remember correctly, 2H is selectable in slippery mode.

 

[FLSTFI Dave]

According to the manual, Slippery mode defaults to 4H, not 4A. To use Slippery on the pavement, you would want to switch to 4A. The manual correctly states that Slippery mode is not for pavement, but would be after a change to 4A. That's my understanding so far.

There are two 4x4 systems available on the bronco depending on trim. Regular 4x4 it defaults to 4H

with advanced transfer case, slippery defaults to 4A

This is correct, 4A for the advanced 4x4 system.

I drive in 4A full time, and I had assumed its in 2wd unless it needs 3 or 4 wheels, but how to measure that? It's my understanding that the Advanced Transfer Case would allow (apply) slippage to whatever wheels would otherwise bind, and apply power as needed so that there is not the crabbing that occurs when we select 4H on pavement. And there is no crabbing in hard turns on pavement when I'm in 4A, which seems to contradict your findings? This is similar to a Subaru, which claims it is always sending power to all 4 wheels, but it can vary that power. if I understand correctly, Subary has 4 viscous "clutches" closer to the wheels that apply slippage or power as needed. The clutches are pricey, I've had them replaced.

Big difference can be felt driving on dry pavement between 4A and 4H. 4H is not suppose to be used on dry pavement.

For all of you that are complaining about this being another 4A thread, to be clear this thread is about how Ford says it's okay for 4A in sports mode but not okay 4A in slippery mode.

Ford by default in slippery mode with the Advanced 4x4 system shifts to 4A The below quote is right out of the Ford Bronco owners manual.

SLIPPERY - ADVANCED 4X4 WITH 4A MODE, EXCLUDING: RAPTOR

For less than ideal road conditions, this mode can be used for crossing terrain where a firm surface is covered with loose or slippery material, such as snow or ice. Slippery mode lowers throttle response and optimizes shifting for slippery surfaces. Four-wheel drive auto (4A) is the default four-wheel drive mode. Two-wheel drive high (2H) is not selectable in slippery

 

[Rjacks258]

You know it's a funny thing, don't actually have to read threads that you're not interested in.

Move along, these aren't the droids you're looking for.

What is also a funny thing, if you choose to read the threads you could save time not having another 8 page+ thread because the correct info is out there……

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