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I did learn something I had always suspected might be true. That even in 4 LOW, the system is easing up the clutch for turns so wheels don't slip or bind. It's pretty sad that you can read the O.M. and all the Jeep literature and not get one clue how their equipment actually works. You left with hearsay and guessing.

For the O,P. that means what I mentioned about 4 LOW might start trenching if you're turning, that is less likely, but it can still happen in 4 LOW, you just have to watch out for it.
Here is the real world test. In 4 high the transfer case will stop sending power to the front wheels when the steering wheel is turned. In 4 low this behavior does not happen. All these tests were done in AUTO mode.

This is the steering angle as reported by AlfaOBD when its straight


This is the steering angle when the wheel is turned



Here is a video I made showing how the transfer case stops sending power as steering angle is increased.


Here is a video doing the same thing but in 4-low. Notice there is no change in the power applied to the clutches no matter what position the steering wheel is in.


You'll notice there is no change in transfer case clutch lock torque in 4-low meaning that steering angle has no affect when in 4-low.

Other food for thought. If you wanted to figure out torque split. Assuming 1710nm is fully locked meaning 50/50 F/R The system always transitions from RWD back to some fwd bias when at low speeds and at a stop. The T-Case Clutch lock torque is usually around 500nm or so. Meaning when taking off from a stop the QDII system has a power split of approximately 30F/70R under normal circumstances (no slipping or WOT throttle).

Since you now know how the torque split works in reality (not just what a manual says) you can watch this video and see how at low speeds and when taking off from a stop there is that 30/70 split and how most of the time the vehicle is in RWD mode.

 

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There is a method to make it RWD and it doesn't require physical modification, it's called pulling the F77 fuse which disables the "AWD/4x4" system and makes it RWD only. On QDII vehicles this also disables the ELSD but the brake lock differential still functions
This is interesting! So let's say I was offroading in my QT2 WK2, and I shredded a front CV joint. I could just pull fuse F77 and be able to drive my car home in RWD?
 

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There is a method to make it RWD and it doesn't require physical modification, it's called pulling the F77 fuse which disables the "AWD/4x4" system and makes it RWD only. On QDII vehicles this also disables the ELSD but the brake lock differential still functions
What are the physical ramifications for running this way? I cannot imagine Jeep intended for this to be a way to use the vehicle.
 
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What are the physical ramifications for running this way? I cannot imagine Jeep intended for this to be a way to use the vehicle.
I'm curious about this, too. I wouldn't ever plan to drive it like that long-term, but it would be great if it meant the difference between making it back home, or having to call an offroad recovery tow service ($$$). Once I got it home, I wouldn't drive it again until the problem was fixed (it's not my daily driver).

The fuse is labelled "Drivetrain Control Module/Front Axle Disconnect Module"
 
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What physically makes the vehicle not send power to the front? Cutxh activation or lack of. I see absolutely no reason for there to be an issue. Again the QDII system runs the vehicle in RWD so much that there shouldn't be a single thing wrong with forcing it for RWD especially in a circumstance like mentioned above.

What people fail to realize is this transfer case is used in other vehicles which have a selectable rwd only mode, its simply not activated/used on the WK2 platform. No clutch engagement = rwd. F77 fuse = no clutch engagement
 

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I thought that most of this covered with the open dif, torque splits, brake force distribution .. a clutch packs allowing/disallowing engagement of drive wheels was a known fact, but I digress. Hat’s off to @Tyler-98-W68 for posting that. And I think it’s a toss up between Subaru and Audi between the best AWD system. (let’s see where this goes)
 

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Well this tow in 4Low gained some traction, didn’t it, lol.
We got a little off-track for sure, but it has spawned some interesting conversation!

What physically makes the vehicle not send power to the front? Cutxh activation or lack of. I see absolutely no reason for there to be an issue. Again the QDII system runs the vehicle in RWD so much that there shouldn't be a single thing wrong with forcing it for RWD especially in a circumstance like mentioned above.

What people fail to realize is this transfer case is used in other vehicles which have a selectable rwd only mode, its simply not activated/used on the WK2 platform. No clutch engagement = rwd. F77 fuse = no clutch engagement
In that case, it sounds like one could use a fuse-tap on F77, and wire a toggle switch to the cabin to trigger forced-RWD on the fly. I'm not sure I'll volunteer to be the first guinea pig, though (and who knows what would happen if you did that while the car was on)
 

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That would be a good idea however to avoid any issues I would only engage that with the vehicle off and not do it on the fly. The canbus system absolutely would freak out. Again the problem with the RWD method for QDII people is it disables the ELSD and really doesn't have any useful purpose (I suppose if you want to burn out all the time)but it can be used in emergency situations.
 

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Here is the real world test. In 4 high the transfer case will stop sending power to the front wheels when the steering wheel is turned. In 4 low this behavior does not happen. All these tests were done in AUTO mode.

This is the steering angle as reported by AlfaOBD when its straight

This is the steering angle when the wheel is turned

Here is a video I made showing how the transfer case stops sending power as steering angle is increased.

Here is a video doing the same thing but in 4-low. Notice there is no change in the power applied to the clutches no matter what position the steering wheel is in.

You'll notice there is no change in transfer case clutch lock torque in 4-low meaning that steering angle has no affect when in 4-low.

Other food for thought. If you wanted to figure out torque split. Assuming 1710nm is fully locked meaning 50/50 F/R The system always transitions from RWD back to some fwd bias when at low speeds and at a stop. The T-Case Clutch lock torque is usually around 500nm or so. Meaning when taking off from a stop the QDII system has a power split of approximately 30F/70R under normal circumstances (no slipping or WOT throttle).

Since you now know how the torque split works in reality (not just what a manual says) you can watch this video and see how at low speeds and when taking off from a stop there is that 30/70 split and how most of the time the vehicle is in RWD mode.
Now I'm confused, I can see my own experience is just I missing the wheels slipping off road in 4 LOW. But MacDaddy swears he's driven on dry pavement in 4 LOW, turning with no binding or difficulties. Something wrong with his transfer case?

This is interesting! So let's say I was off-roading in my QT2 WK2, and I shredded a front CV joint. I could just pull fuse F77 and be able to drive my car home in RWD?
The MP3023 Transfer Case directly drives the rear drivetrain, there is no differential between the rear output and main shaft. The Clutch Pack is just engaging to transfer power to the front drivetrain. So no matter what happens to the front drivetrain, you will have power to the rear wheels, whether pull a fuse or not. Of course things wrong with the front drivetrain could cause more damage to the front drivetrain as you drive. So totally circumstances dependent on if you can drive or not with certain drivetrain failures, BUT, the rear wheels will always be driven regardless (unless of course the failure is the transfer case to the rear output).

What are the physical ramifications for running this way? I cannot imagine Jeep intended for this to be a way to use the vehicle.
Jeep did not design the MP3023 transfer case, Magna Powertrain did. Magna Powertrain designed the Transfer Case to run RWD. But it needs a discrete signal on one circuit at a specific voltage to set RWD mode. Pulling the fuse might not provide that, as well for all modes besides RWD, the computer has to actively manage the clutch pack, RWD mode simply provides zero pressure to the clutch pack. So in theory, as long as you have no pressure on the clutch pack you are in RWD mode, of course in practice can be different. Someone is going to have to risk it and see, if we are to ever get the answer.

Here's what my 2014 owners manual, latest revision I have, says about when you should not use 4WD LO... it's for loose, slippery road surfaces only.

View attachment 238684
I searched my 2011 O.M., there is nothing about this at all in the 2011 O.M. It does say 4 LOW does lock front and rear driveshafts together. Nothing about on for loose surfaces or NOT use on dry pavement, etc.....
 

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Anyone that says they don't get binding in 4 low is flat out lying.

I can still get power to transfer to the front with the wheels turned if I lose traction and it will send power to the front and then taper off after the traction is regained In 4 high. Anyone wanting to debate my results is welcome to but they better have some solid data and not feelings or opinions
 

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Anyone that says they don't get binding in 4 low is flat out lying.
I can also attest to 4low auto absolutely binds, at least in the 2020 I test drove. The sales person brought it over from their dirt lot, parked it without shutting off, and I hopped in for a test drive. As soon as I tried to turn out of the parking spot, I noticed the binding and skipping, even though it was my very first experience with a 4x4. Yes, it's that obvious.

I ended up not buying that car for other reasons, but can absolutely confirm binding in 4low auto.

I ended up buying a 2017, and haven't had the urge to accelerate the wear on my own car to confirm this on a 2017.
 

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peta, as long as 4lo is used in conditions specified (off hard surfaces), there shouldn't be any wear acceleration.
 

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Now I'm confused, I can see my own experience is just I missing the wheels slipping off road in 4 LOW. But MacDaddy swears he's driven on dry pavement in 4 LOW, turning with no binding or difficulties. Something wrong with his transfer case?


The MP3023 Transfer Case directly drives the rear drivetrain, there is no differential between the rear output and main shaft. The Clutch Pack is just engaging to transfer power to the front drivetrain. So no matter what happens to the front drivetrain, you will have power to the rear wheels, whether pull a fuse or not. Of course things wrong with the front drivetrain could cause more damage to the front drivetrain as you drive. So totally circumstances dependent on if you can drive or not with certain drivetrain failures, BUT, the rear wheels will always be driven regardless (unless of course the failure is the transfer case to the rear output).


Jeep did not design the MP3023 transfer case, Magna Powertrain did. Magna Powertrain designed the Transfer Case to run RWD. But it needs a discrete signal on one circuit at a specific voltage to set RWD mode. Pulling the fuse might not provide that, as well for all modes besides RWD, the computer has to actively manage the clutch pack, RWD mode simply provides zero pressure to the clutch pack. So in theory, as long as you have no pressure on the clutch pack you are in RWD mode, of course in practice can be different. Someone is going to have to risk it and see, if we are to ever get the answer.


I searched my 2011 O.M., there is nothing about this at all in the 2011 O.M. It does say 4 LOW does lock front and rear driveshafts together. Nothing about on for loose surfaces or NOT use on dry pavement, etc.....
Look again, or perhaps there is more than one version... This is what I see for the 2011 manual

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