Does the Bronco Raptor have IWE - Integrated Wheel Ends?

[Laminar]

Holy crap...took forever to find but yes, they did put IWEs on them, WTF.

Brilliant, thank you for the info!

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[Laminar]

New F150 and I believe bronco no longer use vacuum IWE, but instead is electronically controlled. Sure looks like a spot for vacuum hose on Braptor, could look under hood to see if vacuum solenoid is there?

The new F-150s have an electronically-actuated IWE on some models, and no IWE on other models. The electronic IWEs still have a vent hose to account for air displaced when the collar moves.

https://www.f150forum.com/f34/4x4-actuators-502426/#post6952063

The BRaptor is the only Bronco to have any IWEs, and these appear to be the old full vacuum style.

 

[dgorsett]

Holy crap...took forever to find but yes, they did put IWEs on them, WTF.


System Operation

IWE System

IWE System Vacuum Diagram 3.0L

Item	Description
1	Brake booster
2	Vacuum pump
3	IWE vacuum reservoir
4	IWE solenoid
5	IWE vacuum actuator LH
6	IWE vacuum actuator RH

The IWE system consists of the following:

1	IWE s (spring-loaded vacuum hubs)
2	Vacuum hoses
3	IWE solenoid
4	Vacuum reservoir

The IWE system uses a vacuum solenoid and vacuum actuated hubs to engage or disengage the front wheel hubs from the front half shafts.

When the 4WD system is in 2WD (2H) mode, the AWD module supplies a ground path to the IWE solenoid to apply engine vacuum to the IWE s thus disengaging the front hubs from the front half shafts. To maintain vacuum during all modes of engine operation, a one way vacuum check valve and a vacuum reservoir are positioned between the vacuum source and the IWE solenoid.

When operating in any 4WD mode, the AWD module does not supply the ground path to the IWE solenoid. Vacuum is not applied to the IWE . An internal spring keeps the IWE clutch ring engaging the front hub and the front half shaft.

The AWD module has two startup strategies that affect IWE operation after initial key cycle:

• When ambient temperature is below 32 F (0 C), the IWE engage after initial key cycle and a driven gear is selected. The hubs stay engaged regardless of a 4x4 mode change for approximately 2 miles (3km). Once the set distance has been achieved, the IWE disengage (if the vehicle is in 2WD (2H)). Distance traveled resets only if the temperature is below calibrated threshold and another key cycle occurs or if customer shifts to Park (P) and back to a driven gear within the same key cycle. The AWD module uses this strategy to warm up the front axle in cold temperatures to improve driveline synchronization.
• When ambient temperature is above 32 F (0 C), the IWE engage after the initial key cycle and a driven gear is selected. The hubs stay engaged regardless of a 4x4 mode change for approximately 0.5 miles (0.8km). Engagement only occurs once per key cycle and is not reset when shifting between Park (P) and Drive (D). The AWD module uses this strategy to delay vacuum use until vacuum-intensive engine startup has completed and sufficient vacuum is available to fully disengage the IWE .

Four-Wheel Drive

The 4WD (four wheel drive) systems consists of:

• Transfer case
• Driveshafts
• IWE
• Front axle
• Rear axle
• AWD module
• ATCM

The transfer case has five modes of operation:

• 2H - Two-wheel drive high
• 4A – Four-wheel drive auto
• 4H - Four-wheel drive high
• 4L - Four-wheel drive low
• Neutral – For recreational flat towing

(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, is available when in (4L).
• The rear electronic locking differential, 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).

Thanks flip, fascinating. So with advanced 4x4 the transfer case uses the electronic system to lock into 4H:
"(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. "

Without Advanced 4x4 (parttime) is the lock up electronic or mechanical (though electrically shifted)?

 

[flip]

Thanks flip, fascinating. So with advanced 4x4 the transfer case uses the electronic system to lock into 4H:
"(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. "

Without Advanced 4x4 (parttime) is the lock up electronic or mechanical (though electrically shifted)?

I think mechanical as the guts of the t-cases are different styles.

 

[flip]

I need it 'splained why they went with IWE, being they've been so reliable in the past, on vehicle that didn't spend much of their lives off pavement.

Is the front axle undersized for the additional hp, torque and wheel size? The IWE will keep more of the 4x4 stress at the end of the wheel instead of all inside the diff locker mechanism. My theory may be wrong but that's the only thing I can come up with right now. It's not like you can lock these independently without the 4x4 engaged and get any benefit. Someone please change my mind.

 

[Deleted member 31057]

I need it 'splained why they went with IWE, being they've been so reliable in the past, on vehicle that didn't spend much of their lives off pavement.

Is the front axle undersized for the additional hp, torque and wheel size? The IWE will keep more of the 4x4 stress at the end of the wheel instead of all inside the diff locker mechanism. My theory may be wrong but that's the only thing I can come up with right now. It's not like you can lock these independently without the 4x4 engaged and get any benefit. Someone please change my mind.

Maybe for the simple fact so the engineers could pull it off of the already designed F150 like the other parts and get the Bronco Raptor revealed.
Helps keep cost down and testing already done!

 

[Laminar]

I need it 'splained why they went with IWE, being they've been so reliable in the past, on vehicle that didn't spend much of their lives off pavement.

Is the front axle undersized for the additional hp, torque and wheel size? The IWE will keep more of the 4x4 stress at the end of the wheel instead of all inside the diff locker mechanism. My theory may be wrong but that's the only thing I can come up with right now. It's not like you can lock these independently without the 4x4 engaged and get any benefit. Someone please change my mind.

Advantages of the IWE:
- Increase fuel mileage by not spinning front axles and diff and driveshaft in 2H modes
- Decrease wear on front diff when driving in 2H modes

Disadvantages of the IWE:
- Unreliable, extra moving parts
- Extra source of lash in drivetrain

IWEs don't affect the stress on upstream components when they're activated - the diff still carries the full load from each wheel and all of the related stresses. The spider gears and diff lock (if equipped) don't see the IWEs once they're engaged, they essentially create a solid connection from diff to wheel hub.

The initial 4x4 engagement is managed by the clutch in the transfer case so the IWE doesn't relieve that stress either.

 

[Laminar]

Maybe for the simple fact so the engineers could pull it off of the already designed F150 like the other parts and get the Bronco Raptor revealed.
Helps keep cost down and testing already done!

Ford has a version of the knuckle that doesn't use IWEs, at least on the 2021+ trucks.

And the vacuum IWEs got so bad that if the vehicle has repeated IWE issues, they recommend deleting them altogether, the kits exist and are readily available.

 

[flip]

Advantages of the IWE:
- Increase fuel mileage by not spinning front axles and diff and driveshaft in 2H modes
- Decrease wear on front diff when driving in 2H modes

Disadvantages of the IWE:
- Unreliable, extra moving parts
- Extra source of lash in drivetrain

IWEs don't affect the stress on upstream components when they're activated - the diff still carries the full load from each wheel and all of the related stresses. The spider gears and diff lock (if equipped) don't see the IWEs once they're engaged, they essentially create a solid connection from diff to wheel hub.

The initial 4x4 engagement is managed by the clutch in the transfer case so the IWE doesn't relieve that stress either.

I just feel like this is a less robust system for what it's on and has a historically higher failure rate than direct spline. Yes, if you lose vacuum your hubs will be engaged. Ok on a trail where the failure engages the front axles, not so much for daily driving. It's much more difficult to blow out a through spline setup as opposed to one of these and if that does happen to one or both, makes your front worthless.

Not an engineer but I wouldn't have designed the Raptor (big tires, more hp, designed for more severe off-roading) with this setup. Seen waaaaaaaaaay too many come through service with IWE on pavement driven vehicles with failures. Would rather have the same design as other broncos, just heavier duty. IWE on a performance vehicle feels like we're going backwards.

 

[Laminar]

Yes, if you lose vacuum your hubs will be engaged. Ok on a trail where the failure engages the front axles, not so much for daily driving.

It's perfectly fine for daily driving. It just means the front axles and diff are engaged and spinning even though the front end is not driven. There is still a diff, so it doesn't lock the front wheels together. Plenty of people drive around on failed IWEs or with IWE delete kits. It's just a 1-2mpg hit, no real impact to driving performance otherwise.

Most Broncos are already this way.

 

[BigMeatsBronco]

Informative! How dumb of a design!!! Now if it had wet clutches in there on beveled rollers???...that would be fantanstic...but the vacume activated splines are super stupid in my opinion. When I raptorize my FE Ill be using the other knuckles that ommit this junk!

 

[Bmadda]

Finally a reason to be glad I DIDN'T get a Braptor! (other than 4dr only and automatic only, and being too wide for most places I wheel)

 

[dgorsett]

Does not sound like a good idea on any vehicle with 4A. Especially one designed for high performance driving. I've had a few IWE vehicles and they've been fine, but not designed or driven as high performance. I'm glad my BB doesn't have them or even FAD. Flips detailed info makes it sound like they tried to design it with as many fail points as possible. Relying on the ambient temp sensor? Come on...

 

[Laminar]

Does not sound like a good idea on any vehicle with 4A.

The 2021+ F-150s omit them on some models, usually the ones with 4A.

That being said, they engage when you switch it to 4A and stay engaged regardless of what the TC is doing, so it's not a detriment to function as long as they're working.

 

[vrtical]

I may just disable them which puts them in locked mode, better then dealing with them hung up and not engaging it will just be like a normal Bronco.

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