Transfer Case Technical Discussion

[SierraBronco]

Have you checked out Vasher Designs VX Offroad rear trailing arms/suspension?

Yep! Already ordered his shock towers for the back. Currently have a set of 32 spline UFDU front CV's on the way to him to get measurements on how far the center bars need extended as he hasn't worked with the chonky boi front drive unit yet. He's also going to go to 1.5" uniballs top and bottom for us and set up the LCA's for bypasses. Stretched D60 with oxlocker currently being assembled as well.

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[mpeugeot]

Onlyfans. Lot of lonely gay dudes out there.

This is the way.... LOL

 

[nmmike]

Forgive me if this has been covered already in this thread but I'm wondering if the 4A transfer case can be replaced with the part time transfer case without jumping through a bunch of hoops.

 

[dgorsett]

Forgive me if this has been covered already in this thread but I'm wondering if the 4A transfer case can be replaced with the part time transfer case without jumping through a bunch of hoops.

AWD module, wiring harness and some programming as a minimum

 

[mattusmc]

Haven’t called them yet to see if the BW4808 would work with their kit, but I’m hopeful.

https://www.behemothdrivetrain.com/...arner-electric-to-manual-shift-conversion-kit

 

[Felix808]

Haven’t called them yet to see if the BW4808 would work with their kit, but I’m hopeful.

https://www.behemothdrivetrain.com/...arner-electric-to-manual-shift-conversion-kit

I like the possibility of a twin stick

 

[NC_Pinz]

I'm interested to see someone install and then mod their interior to accommodate / integrate a single or twin stick.

Beyond the off road aspects of not having a component fail and leave you stranded, I'm wondering about those that want the extra insurance when flat towing that your transfer case. Manual shifter means you wouldn't have an unintended shift while towing that some folks have had.

 

[dgorsett]

I like the possibility of a twin stick

Nice, but pricy. Someone needs to go first and see how the shifter integrates to the Bronco interior and gets along with electronics.

As far as flat tow, it would be a feeling of assurance for me with the part time case, but it may not actually help those who have had the problem with 4A cases. It is my belief that flat tow issues are not caused by an inadvertent shift, but by the 4A clutches hanging up in neutral.

 

[Felix808]

Nice, but pricy. Someone needs to go first and see how the shifter integrates to the Bronco interior and gets along with electronics.

That's the nice ting about a cable shifter is you can route it pretty much anywhere.
I imagine that you may have to keep the shift motor connected, but one would hope it would play nice. But if not wire the lockers to an independent switch & twin stick it & the electronics can KMA!

I'll try to remember to give them a call tomorrow to see if I can fish out some more details, but
I do agree that I won't be the Beta tester

 

[mattusmc]

I figure once the stock tcase goes to shit, swap it out for one of their D300 4:1 Apex cases pricing seems reasonable for what you get https://www.behemothdrivetrain.com/products/fully-assembled-4-1-lomax-geared-dana-300-apex-3

 

[Felix808]

I figure once the stock tcase goes to shit, swap it out for one of their D300 4:1 Apex cases pricing seems reasonable for what you get https://www.behemothdrivetrain.com/products/fully-assembled-4-1-lomax-geared-dana-300-apex-3

Good find!. This would be the better way to go. For just a little bit more You get a gear driven case that is much stronger inside & out. It will also give you a more controlled ride due to less surging that you get from a planetary gear setup. But there is the often difficult to shift without rolling a little to mesh the gears.
No sense calling until the case is blown .

 

[Felix808]

So I made a call & I was lacking a little bit of info going in as I couldn't quite recall the exact model # of the Xfer case, but from the conversation I gained the following info:

1. Electronics compatibility on the 6G is an unknown at this time.


2. Without the model # of xfer case, one would need to take off the shift motor to inspect the interface between the motor & the xfer case to confirm compatible mechanically.
a. If anyone knows the exact models, I can give them a call back & update.
1. Shouldn't be too hard to figure out for someone with some spare time.

(Edit) 3. Twin sticking our cases does not look like an option reading through the website, so the video is more of a list of products they have but not designed to work with the electric to manual xfer case conversion that I can see.

4. Looking back at the D300 Apex I miss saw the price at %50

so would have to think about this over an Atlas that I have a bigger range of gearing choices, but I do like that it is lighter

 

[Raybj]

Four-Wheel Drive Systems - System Operation and Component Description
System Diagram





System Operation

Four-Wheel Drive

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

• Transfer case
• Driveshafts
• 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, 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).

G.O.A.T. Mode availability by series

	Normal	Eco	Sport	Slippery	Mud	Sand	Baja	Rock
Base	x	x	x	x		x
Big Bend	x	x	x	x	x	x
OuterBanks	x	x	x	x	x	x
Wildtrack	x	x	x	x	x	x	x
Black Diamond	x	x	x	x	x	x		x
Badlands	x	x		x	x	x	x	x

Component Description



All Terrain Control Module (ATCM)

The ATCM contains the G.O.A.T. modes rotary dial, 2H, 4H, and 4L switches. The ATCM is the logic module for the front and rear ELD , the stabilizer bar disconnect, and all G.O.A.T. mode features.

AWD module

The AWD module is the logic module for the four-wheel drive system. Multiple modules/system inputs are used for the four-wheel drive system to determine the percentage of torque to be transferred to the front wheels.

Transfer Case

A supplementary gearbox attached to the transmission. The transfer case directs power to the front drive axle via the front drive shaft.
Refer to: Transfer Case (307-07D Transfer Case - Advanced 4x4 with 4A Mode, Description and Operation).

What causes the 4wd to "Temporarily unavailable " on the main screen. This happens at the most unoppertune moments, in 4L front locked trying to get out of mud??

 

[flip]

It would be easier to try and address your specific fault that's triggering the message as opposed to making a list of the things that could cause it. If I was going to make a list of general things it would probably look like this...Other system fault locking out 4x4, software, network communication issues, water in connector, vehicle in a situation where conditions do not allow 4x4 engagement.

Give me the VIN and I can see what your VHR says and give some likely systems that may be causing it.

Any issues here and no workie.

 

[Snacktime]

Getting away from planetary gear sets also let's you spin the assembly faster. Lot of early planetary reduction boxes had issues with burning up.

Really need someone to build a doubler so we can figure what is the limiting factor in the current transfer case.

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