Anyone HAPPY with Borg Warner 44-44 / Auto 4WD

[smiley]

They made changes to the 44-44 in 2017 model year so may not be as bad now? Anyone have a 2017 want to chime in?

 

[Hemi395]

They made changes to the 44-44 in 2017 model year so may not be as bad now? Anyone have a 2017 want to chime in?

Do we know what changes?

 

[WilliamS]

That is exactly the problem William. As soon as the speed difference between the axles is the same it disengages. Then when it slips a second later it re-engages. When it repeats over and over the clutches heat up.

That doesn’t explain why I get power to both axles without slip. If that were the case the fronts would never see power on pavement like at a drag strip or pulling too heavy a boat out. With what easy tests I’ve done I can prove easily the rear tires do not need to spin before the front see power. I just want to see the guts of this thing my suspicion is that it’s like the xdrive center differential it can be torque sensing or torque anticipating on demand based on requested load.

There is more to this than meets the eye.

 

[cbsmith]

That doesn’t explain why I get power to both axles without slip. If that were the case the fronts would never see power on pavement like at a drag strip or pulling too heavy a boat out. With what easy tests I’ve done I can prove easily the rear tires do not need to spin before the front see power. I just want to see the guts of this thing my suspicion is that it’s like the xdrive center differential it can be torque sensing or torque anticipating on demand based on requested load.

There is more to this than meets the eye.

Post 253on this thread has an explanation of all the parts from a guy who actually disassembled his transfer case. The next few pages after that have further explanation.

http://www.ramforum.com/posts/1520494/

 

[ColdCase]

Thanks, I've searched for that post for an hour yesterday. I wasn't sure if the ball ramp was energized in auto or not, and my memory failed me. Sounds like, perhaps, they designed the controller to accommodate both a more typical clutch based transfer case (completely controlled by software) or the BW 44-44.... just to keep their options open.

I'm still trying to find the equivalent info on the front axle lock I know its a motor that slides a locking spline, but dunno the state its in for all the modes.

 

[cbsmith]

I would think the front axle disconnect would need to be connected in any of the 4x4 modes, auto included due to the fact that a sliding splines shaft should not be engaged when the two shafts are not rotating at the same speed.

 

[Hemi395]

So after rereading post 253, it looks like it's not a simple programming fix for this if the electromagnetic clutch is activated constantly while in 4lock and 4low. I'm still trying to wrap my brain around the whole ball ramp system...

 

[WilliamS]

So after rereading post 253, it looks like it's not a simple programming fix for this if the electromagnetic clutch is activated constantly while in 4lock and 4low. I'm still trying to wrap my brain around the whole ball ramp system...

The implied function does not work that way. As it stated the clutch energizes allowing the ball ramp to do its job and the function requires a speed difference between the front and rear axles. I have a problem with this theory, as I can prove without much effort that both axles can be powered with zero difference in speed.

There has to be another function in the transfer case that hasn't been articulated yet. Just like the GM and Ford TOD transfer cases made by Borg Warner, they have pre-emptive torque lock up which under certain load and request conditions will engage the front axle without slip needed to send power.

This leads me to believe that the transfer case is capable of a full lock up with software, but that requires someone much smarter and more capable than me. I think the reason they did not as the case itself the way its built with the clutch system is not strong enough for the front to have the full power of the truck in many situations.

 

[ColdCase]

The gear guys say most of the case/chain/gears components of the 44-44 is stronger than the 44-45. Hence a secondary interest in turning a 44-44 into a stronger 44-45 which they did successfully mechanically. There is a post or article around here somewhere showing the details. The prototypes worked well. Its just the truck's computer didn't like it.

Mentioned before, you will normally get 20-40 ftbls of torque delivered to the front axle in 4 Lock regardless of slip, yours may have a stiffer/weaker spring or stronger magnet... or perhaps its not a 44-44 Just saying that I don't think anyone else reported the same type of function as you do, which could be the tolerance thing.

 

[chrisbh17]

Somewhat related - Ive been getting the dreaded 2000 RPM vibration. Yesterday was the first day I technically needed 4WD, so I had it in 4 Auto. And the vibration was noticeably worse in 4WD-Auto than 2WD. It almost felt like something was rubbing (front driveshaft, perhaps?)

The reason I mention that here is because, if our theories on 4-Auto operation are correct, there should be NO difference between 2WD and 4-Auto until the rear wheels slip (which they were not at the time), yet it was definitely noticeable. No matter what is causing the engine vibration, it technically shouldn't have changed when in 4-Auto, because its always been RPM and/or load related, neither of which should have changed with "just" the electromagnet in a position to allow the front wheels to spin if necessary.

Im curious enough that Im going to look into some mounts for my son's Go Pro and mount it under the truck to see if the front driveshaft spins any during 4-Auto without rear wheel slip.

Maybe they are sending SOME torque to the front wheels regardless of rear wheel slip? EDIT: just noticed ColdCase had the same theory, but I was in 4 AUTO not 4 LOCK, so maybe there has been a change (s/w or h/w) that causes the front to get some torque no matter what.

And if it means anything, I have a 2017.

 

[WilliamS]

Somewhat related - Ive been getting the dreaded 2000 RPM vibration. Yesterday was the first day I technically needed 4WD, so I had it in 4 Auto. And the vibration was noticeably worse in 4WD-Auto than 2WD. It almost felt like something was rubbing (front driveshaft, perhaps?)

The reason I mention that here is because, if our theories on 4-Auto operation are correct, there should be NO difference between 2WD and 4-Auto until the rear wheels slip (which they were not at the time), yet it was definitely noticeable. No matter what is causing the engine vibration, it technically shouldn't have changed when in 4-Auto, because its always been RPM and/or load related, neither of which should have changed with "just" the electromagnet in a position to allow the front wheels to spin if necessary.

Im curious enough that Im going to look into some mounts for my son's Go Pro and mount it under the truck to see if the front driveshaft spins any during 4-Auto without rear wheel slip.

Maybe they are sending SOME torque to the front wheels regardless of rear wheel slip? EDIT: just noticed ColdCase had the same theory, but I was in 4 AUTO not 4 LOCK, so maybe there has been a change (s/w or h/w) that causes the front to get some torque no matter what.

And if it means anything, I have a 2017.

This is likely the cause of that noise.

http://www.ramforum.com/posts/487548/

 

[WilliamS]

The gear guys say most of the case/chain/gears components of the 44-44 is stronger than the 44-45. Hence a secondary interest in turning a 44-44 into a stronger 44-45 which they did successfully mechanically. There is a post or article around here somewhere showing the details. The prototypes worked well. Its just the truck's computer didn't like it.

Mentioned before, you will normally get 20-40 ftbls of torque delivered to the front axle in 4 Lock regardless of slip, yours may have a stiffer/weaker spring or stronger magnet... or perhaps its not a 44-44 Just saying that I don't think anyone else reported the same type of function as you do, which could be the tolerance thing.

Isnt there someone supercharged with the 44-44 trasnfer case. Id like to see his launches, again Ill bet the rear tires do not spin more than the fronts when he takes off from a dig, but in 2wd itll spin.

 

[chrisbh17]

This is likely the cause of that noise.

http://www.ramforum.com/posts/487548/

It would make my day if thats it! Its an actual vibration (no noise, though) making it into the cab (floorpan, gas pedal, steering wheel) but one of the possibilities is that something is resonating at the correct frequency...and something like transmission lines could be it. Ive looked around plenty under the truck and am not 100% impressed with the routing of some of the lines ( a couple of them seem to be just resting on the top of the frame in a couple places)

Have a second dealer appointment for it.

But, back on topic - Im currently looking into the mount(s) and case(s) necessary for my son's Go Pro, so I can fasten it under the truck and run it around in 2WD and 4 Auto to see exactly what happens. If I can get the stuff with Prime shipping, hopefully the experiment can commence early next week.

 

[cbsmith]

The implied function does not work that way. As it stated the clutch energizes allowing the ball ramp to do its job and the function requires a speed difference between the front and rear axles. I have a problem with this theory, as I can prove without much effort that both axles can be powered with zero difference in speed.

There has to be another function in the transfer case that hasn't been articulated yet. Just like the GM and Ford TOD transfer cases made by Borg Warner, they have pre-emptive torque lock up which under certain load and request conditions will engage the front axle without slip needed to send power.

This leads me to believe that the transfer case is capable of a full lock up with software, but that requires someone much smarter and more capable than me. I think the reason they did not as the case itself the way its built with the clutch system is not strong enough for the front to have the full power of the truck in many situations.

How can you determine if power is being applied to the front wheels without the rear wheels slipping? The only way to determine if power is applied to the front wheels would be if they were spinning, which would also mean the back wheels were spinning so it would be hard to tell.

If you put it in 4-Lock on dry pavement and then try to make a truck at idle speed or just above is there any driveline binding? If it is truly locked it should bind up pretty quickly.

 

[chrisbh17]

How can you determine if power is being applied to the front wheels without the rear wheels slipping? The only way to determine if power is applied to the front wheels would be if they were spinning, which would also mean the back wheels were spinning so it would be hard to tell.

If you put it in 4-Lock on dry pavement and then try to make a truck at idle speed or just above is there any driveline binding? If it is truly locked it should bind up pretty quickly.

Looking under the truck I think it would be pretty easy....my understanding of the system is that the electromagnet that allows for the front wheels to be driven is internal and the ONLY thing that gets locked when the 4 Auto button is pressed. The front driveshaft, if my understanding is correct, will still be "free" in the sense that you should be able to turn it by hand.

Once the rear wheels slip, that driveshaft should spin which in turn drives the front wheels. Once you back off the throttle or the fronts spin at the same speed as the rears, the front driveshaft should go back to "free".

So, if you could see underneath the truck while in 4 Auto, it would be verification that the front gets driven with or without the rear wheels slipping.

The fact my vibration gets worse in 4 Auto than in 2WD makes me think there is at least SOME torque getting to the front wheels regardless of rear wheel slip.

 

[WilliamS]

How can you determine if power is being applied to the front wheels without the rear wheels slipping? The only way to determine if power is applied to the front wheels would be if they were spinning, which would also mean the back wheels were spinning so it would be hard to tell.

If you put it in 4-Lock on dry pavement and then try to make a truck at idle speed or just above is there any driveline binding? If it is truly locked it should bind up pretty quickly.

This is accurate, give it enough throttle to not spin the tires but accelerate, it will bind up instantly without the wheel spin.

Again with a gopro on 240 fps park in the sand, give it more than half throttle ll wheels will spin simultaneously , let the video do the work for you. Take the same setup and give it 10% throttle the rears will spin almost a full rotation before the fronts grab. Sand is the easiest test, but asphalt, snow, ice, muck would all confirm this. On new rain roads I can do the exact same test.

I could be some crackpot lunatic but I know there are situations that the center differential will lock up and I think there is a load request that will do it. I know it will disconnect once the front wheels are turned enough which again could be a computer lockout as well the ball ramp. The clutch is the weak point to this transfer case, understanding its full function is only the engineers to why it doesn't lock or apply full pressure is likely because it cant handle a 2.5 ton truck being pulled only by the front axle up a steep incline without slip or failure. The case itself might be stronger than the 44-45 but the mechanics are not.

 

[Hemi395]

Anyone think about putting a manual shift 44-47 in? Completely bypass the computer...

 

[cbsmith]

This is accurate, give it enough throttle to not spin the tires but accelerate, it will bind up instantly without the wheel spin.

The ball ramp works on a speed differential between front and back driveshafts. If you are driving or accelerating at any speed and turning the front driveshaft will be turning slower than the rear which the ball ramp will interpret as wheel spin and start to lock up. The reason a 4x4 binds up in a turn is because the front turns slower than the rear. So in a turn the difference between front and rear wheels could be enough to engage the ball ramp.

Go in sand or some other slippery surface and drive straight and there will be rear wheel spin slightly before the ball ramp enages, between 1/2-1 full rotation of the rear wheels.

 

[Murphy Slaw]

Isnt there someone supercharged with the 44-44 trasnfer case. Id like to see his launches, again ...........

Seems like I remember that, too.....

 

[LouM]

It would make my day if thats it! Its an actual vibration (no noise, though) making it into the cab (floorpan, gas pedal, steering wheel) but one of the possibilities is that something is resonating at the correct frequency...and something like transmission lines could be it. Ive looked around plenty under the truck and am not 100% impressed with the routing of some of the lines ( a couple of them seem to be just resting on the top of the frame in a couple places)

Have a second dealer appointment for it.

But, back on topic - Im currently looking into the mount(s) and case(s) necessary for my son's Go Pro, so I can fasten it under the truck and run it around in 2WD and 4 Auto to see exactly what happens. If I can get the stuff with Prime shipping, hopefully the experiment can commence early next week.

One thing that most everyone is missing, as soon as the auto 4 wd or so called lock button is pushed the first thing that happens is the front axle inter connect operates once that happens it is just like an old 4x4 with the hubs locked both sides of the front axle are spined together, then the truck is just waiting to engage the transfer case clutch when it decides to. I am one of the people that do not like or trust this damned t-case.