4WD operation and handling in winter?

[Ken226]

I had actually been looking for that rotational difference info.

Any chance BW changed/updated internal mechanisms in the many years the 44-44 has been produced? Or are they all pretty much the same?

It's possible, but i havn't kept up with the design changes. I'd heard that the 5th gens (possibly Ram Classics too?), got a totally different transfer case that fixed this issue completely. But, i don't know for sure.


The initial resistance that creates drag on the front output, to get the balls to start up the ramps, is provided by part#29 in this diagram:




It's an electromagnetic coil. In 4 auto mode, when the computer detects and front/rear speed difference from the wheel speed sensors, it energizes this coil which creates drag on the ramp mechanism and causes the rear output to engage the mechanism, close the clutch basket (part 18) and transfer power to the front wheels.


In 4 lock, the coil is supposed to stay energized. Back in 2018/2019 when we on this forum were researching this, I seem to remember someone putting an amp clamp on the coil power feed and determining that even in 4 lock, it was only energizing the coil during front/rear wheel speed difference. Basically, doing the same thing as 4 auto. But, someone else did that test so i can't verify it's authenticity.

So, in 4 lock the engagement should be alot quicker, but it still requires the rear output to rotate in advance of the front output, in order for the ballramp mechanism to start working.

The way this case works mechanically, the more wear and tear you have on your TC, the longer it takes to engage the front wheels.

Probably why some guys who live in areas where they don't use it so much, don't mind the system. Guys who work in areas that do lots of climbing up mountains, like real mountains, where the elevation changes are measured in thousands of feet, definitely DO complain about it.

 

[turkeybird56]

All the Auto systems on 1500s up to 2018 basically same. 2019 5th Gen which I have the mapping was modified

OP U need to put snow rated tires on yer ride get away from straight street tread or get another full set in different rims to switch out. ALSO drive responsibly and understand these RAMS are 5500 lbs and up and U have to drive to conditions.

Auto for tooling around on wet roads ok. But if U get into heavier stuff you prob need to go to 4 Hi and remember these transfer cases are clutches not gears so don’t get out there and floor it in a foot of snow.

All above IMHO.

 

[Kraken]

It's an electromagnetic coil. In 4 auto mode, when the computer detects and front/rear speed difference from the wheel speed sensors, it energizes this coil which creates drag on the ramp mechanism and causes the rear output to engage the mechanism, close the clutch basket (part 18) and transfer power to the front wheels.


In 4 lock, the coil is supposed to stay energized. Back in 2018/2019 when we on this forum were researching this, I seem to remember someone putting an amp clamp on the coil power feed and determining that even in 4 lock, it was only energizing the coil during front/rear wheel speed difference. Basically, doing the same thing as 4 auto. But, someone else did that test so i can't verify it's authenticity.

So, in 4 lock the engagement should be alot quicker, but it still requires the rear output to rotate in advance of the front output, in order for the ballramp mechanism to start working.

The way this case works mechanically, the more wear and tear you have on your TC, the longer it takes to engage the front wheels.

Interesting... so I read some reference the other day about 'guys adding a switch' to their setup that helped the 4wd in some fashion. And reading what you've said here it makes sense now. IF it's possible on the 4th gens.

 

[Ken226]

Interesting... so I read some reference the other day about 'guys adding a switch' to their setup that helped the 4wd in some fashion. And reading what you've said here it makes sense now. IF it's possible on the 4th gens.

That's pretty much exactly what they did. The switch overrides the programming and powers that coil full time.

I went the 44-45 swap route, but the guys who installed the lock switch @Brandon-w designed, loved it and said that it made a world of difference.

Maybe Brandon could weigh it on it, but it's been a long time. Not sure he's active on the forum still.

 

[62Blazer]

This is a total mis-application of 4WD Auto. A muddy, rutted mountain road is absolutely not what Auto mode is for.

I've had 3 different 4-Auto equipped vehicles since 2007 (GMC Sierra, Jeep Grand Cherokee, and my current Ram). I have never experienced any of the problems people are suggesting above (gears slamming, poor programming, etc). When applying these different modes for their intended conditions they've all been pretty great, but the Jeep QuadraTrac was amazing. (Note that the GMC had 180K miles and the jeep had 229,500miles when I sold them, and the current 2019 Ram has 148,000 miles)

I was going to say the same thing. I would also suspect something was wrong with the transfer case as I've never seen the rear tires have to "rotate a half dozen turns" for the front tires to engage, especially in 4 lock. Not saying the vehicle in question did not do it, just that I have never seen that. I was an automotive testing engineer for 10+ years and worked with Chrysler/Dodge/whatever their name of the month was at the time quite a bit. If you took off fast in gravel or wet grass in 4 Auto the engagement of the front tires was basically instantaneous. At least during that time several years ago, the difference in 4 auto versus 4 lock was that in 4 auto the front output was not engaged until it sensed slip in the rear tires, and when engaging it would proportionally apply power (not simply on or off). In 4 lock the clutch packs were always fully engaged and did not wait on rear tire slip. Again, that was several years ago so maybe they changed, but I do know that on other models that is how they still work.
The other thing mentioned by another person.....they say within the transfer case it had to rotate "several hundreds degrees" before engaging. 360 degrees is a full rotation, so "several hundred" is less than one rotation in the transfer case. Then in another post they say that the rear tires rotate a half dozen times. If you take into account the gear ratio, the rear tires rotating 6 times is equivalent to the driveshaft rotating around 20 times. Big difference between a couple hundred degrees (less than one rotation) and 20 rotations? Maybe I'm misunderstanding the comments?

 

[joesstripclub]

I was pretty impressed with the 44-44 in my 2018 Sport. Lived in Colorado for almost 5 years and the truck never failed me. I ran Michelin Defenders which are a highway tire, but had pretty good snow traction IMO. Did great hauling snowmobiles up to Vail Pass, up some snowy rutted mountain roads to get to a job site, or just in the many inches of snow that were normal out there. I even went over Mosquito Pass as that seemed like a great idea. Ground clearance was a little low on my running boards and tore the **** out of the factory tires which led to the Michelins, but never had a traction issue that got me stuck.

 

[Ken226]

I was an automotive testing engineer for 10+ years

In 4 lock the clutch packs were always fully engaged and did not wait on rear tire slip.

Ok, so in the exploded diagram above, which part provides the force that is pressing the clutch plates together?

And, how much force can this electromagnetic coil provide, given the 12 volt system and low current drawn by that curcuit?

It's pretty obviously not the coil that does this, but the ballramp, otherwise there wouldn't need to be a ballramp. Given that, what has to occur between the front/rear output shafts of the transfer case in order for the balls to move up the ramps, expand the pressure plates and force the clutch plates into compression?

Now, consider that while on a really slick surface, when the rear wheels start rotating and the clutches move into partial compression, what happens at the front wheels?

The watch a few of the many videos about this subject posted on youtube, and it'll start to make sense. the rear wheels spinning, and the front wheels surging, stopping, turning, stopping, over and over.

 

[Ken226]

It's an old video. There are lots more.

2014 ram Borg Warner 44-44

This video shows the absolute worthlessness of the design of a Borg Warner 44-44 transfer case in high trim level ram 1500 trucks. Ram stands behind this des...

www.youtube.com

Another:

RAM 1500 Off-Road 4WD LOCK Test (It FAILED..) | Real World 4x4 Testing in Snow

Today we are testing the Ram 1500's 4WD system off-road in the snow and it failed. I wanted to see if the Ram's front driveshaft was always given power when ...

youtu.be

His "either/or" at the six minute mark, his 2nd guess is the correct one. When the front wheels slip, the magnitude of the torque forces on the ball ramp drop, and the clutches partially disengage and allow slip, resulting in the rear wheels continuing to turn while the front does not. This, is how you get more revolutions of 1 part relative to the other part.

 

[62Blazer]

Ok, so in the exploded diagram above, which part provides the force that is pressing the clutch plates together?

And, how much force can this electromagnetic coil provide, given the 12 volt system and low current drawn by that curcuit?

It's pretty obviously not the coil that does this, but the ballramp, otherwise there wouldn't need to be a ballramp. Given that, what has to occur between the front/rear output shafts of the transfer case in order for the balls to move up the ramps, expand the pressure plates and force the clutch plates into compression?

Now, consider that while on a really slick surface, when the rear wheels start rotating and the clutches move into partial compression, what happens at the front wheels?

The watch a few of the many videos about this subject posted on youtube, and it'll start to make sense. the rear wheels spinning, and the front wheels surging, stopping, turning, stopping, over and over.

If you are an engineer (like actual degree, from a university) and you don't understand how this works, well, i dont see how that can be possible.

It's an electromagnetic clutch setup, which means you can apply varying amounts of force on the clutch pack which controls how much it locks up. It's not a mechanical lock up design and is all controlled by how much voltage the computer sends to the magnet...more voltage, more clamping. The system is not dependent on the rear tires spinning and some mechanical motion transferring up through the transfer case that is causing it to lock up. The computer monitors the speed difference between the front and rear wheels and as soon as it reaches the threshold difference it sends power to the electromagnet which applies forces to start clamping the clutch packs together. In 4 auto it waits until is sees that small front to back wheel speed difference to start applying the clutches. It will also apply varying amounts of power as needed, so may not always be a 50/50 torque split front to rear. In 4 hi/lock it will go ahead and send full voltage (power) to the electromagnet and lock up the clutches regardless of any wheel speed differences. Go put a truck in 4 auto and drive circles in a parking lot, then put it in 4 hi/lock and drive circles in the parking lot and feel the difference.
You do hear about trucks with 4 auto modes failing and losing power to the front tires sometimes. That is usually in extreme situations as the computer is sending full power to the electromagnet and locking up the clutches as much as possible. However the clutches can only hold so much force before they slip, and if the clutches slip when clamped tightly they will fail. Clutches also simply start wearing out over time. If you use 4 auto a lot, and use it under tough conditions a lot, they will eventually start failing.

 

[Ken226]

I found a video of Brandons switch being tested, from years back

Transfercase lock switch on and off

44-44 transfercase lock switch denonstrationhttps://m.facebook.com/blackfoxindustries/?tsid=0.42515202619174164&source=result

www.youtube.com

 

[Ken226]

It's an electromagnetic clutch setup, which means you can apply varying amounts of force on the clutch pack which controls how much it locks up. It's not a mechanical lock up design and is all controlled by how much voltage the computer sends to the magnet...more voltage, more clamping. The system is not dependent on the rear tires spinning and some mechanical motion transferring up through the transfer case that is causing it to lock up. The computer monitors the speed difference between the front and rear wheels and as soon as it reaches the threshold difference it sends power to the electromagnet which applies forces to start clamping the clutch packs together. In 4 auto it waits until is sees that small front to back wheel speed difference to start applying the clutches. It will also apply varying amounts of power as needed, so may not always be a 50/50 torque split front to rear. In 4 hi/lock it will go ahead and send full voltage (power) to the electromagnet and lock up the clutches regardless of any wheel speed differences. Go put a truck in 4 auto and drive circles in a parking lot, then put it in 4 hi/lock and drive circles in the parking lot and feel the difference.
You do hear about trucks with 4 auto modes failing and losing power to the front tires sometimes. That is usually in extreme situations as the computer is sending full power to the electromagnet and locking up the clutches as much as possible. However the clutches can only hold so much force before they slip, and if the clutches slip when clamped tightly they will fail. Clutches also simply start wearing out over time. If you use 4 auto a lot, and use it under tough conditions a lot, they will eventually start failing.

So, if that is the case, what does the ballramp mechanism do?

Because when I rebuilt mine, it was pretty obvioius that the elctromagnetic clutch was in no possible way able to provide any clamping force whatsoever to the clutch pack. When activated, it provided friction force to retard movement of the ballramp part pictured on the previous page.

 

[Ken226]

Here is the clutch assembly from my spare 44-44. As you can clearly see, there is no electromagnetic mechanism.

The electromagnet is a stator, rigidly affixed to the housing. It does not rotate.

When energized, it magnetically pulls on the dark colored plate in the pic (you can see the friction wear pattern).

This drag slows rotation of the outer part of the clutch the basket, which causes the ball ramp plates to expand and force the clutch into compression. A rotation speed differential between the front and rear output shafts is necessary for the ball ramp to function.




This clutch is from a low mileage bw44-44 case that is nearly new.




Here you can see the wear pattern on the drag plate. The electromagnet pulls this plate against a stator plate in the case, like an electric trailer brake. This forces the ballramp to press the plates together in compression, then the computer turns off the electromagnet. As long as there is a force differential between the front/rear output shafts (as in, there is still some amount of front wheel slip), the ball ramp is supposed to remain engaged.

As soon as you get good traction and the front/rear output shafts are at the same speed, the ballramp not longer compresses the clutches. Or when you make your first turn, the front wheels track a larger radius than the rear wheels and the ballramp mechanically disengages.

 

[Kraken]

@Ken226 Love seeing actual internals! Got any pics of this ball ramp?

And I definitely want to toss in an @Brandon-w Transfer Case Lock switch!

Thinking outloud.. tracing back the wires from the t-case and tapping into the positive side. Trigger a small relay from the 4wd Lock's LED to feed that electromagnetic clutch.. no external switch required and Lock would act more like a lock. Sound reasonable?

 

[Sherman Bird]

So coming from the Ford side and being very familiar with how the F-150 handles the white (and clear) slippery stuff.. I wanted to ask if there were any notable differences with the Ram 1500's? I had no auto-4wd on the Ford so having that in the Ram is a new thing, and I've read a bit about how some of these trucks had crappy programming when it came to that auto lock up. How it 'could' cause extra slippage and heat build up...
Thanks

!

 

[Ken226]

@Ken226 Love seeing actual internals! Got any pics of this ball ramp?

I don't have a spare for the cam and brake hub (the parts that make up the ball ramp assembly). They are in my rebuilt unit, which is in a box out in the shop awaiting the day my 44-45 breaks, then it will probably be reinstalled.

And I don't wanna take it apart for pics

Best I can do is the OEM stock pic of the cam plate, on the previous page.

 

[Kraken]

I don't have a spare for the cam and brake hub (the parts that make up the ball ramp assembly). They are in my rebuilt unit, which is in a box out in the shop awaiting the day my 44-45 breaks, then it will probably be reinstalled.

And I don't wanna take it apart for pics

Best I can do is the OEM stock pic of the cam plate, on the previous page.

No worries!

 

[Ken226]

Here is an old article with good info, and some pics:

Snow plowing = BW 44-44 transfer-case failures - Transmission Digest

Experience we gain from solving problems generated in the transmission repair industry sheds light on various common failures and allows us to see trends that provide new products to solve design issues. From 2011 on, Dodge has offered Ram 1500 pickup trucks equipped with the BW 44-44 transfer...

www.transmissiondigest.com

From the article:
"If the shift command meets the software requirements, the externally mounted shift motor will shift into the desired range. The wet clutch is electromechanical design, using a clutch pack and a ramp-and-ball system to engage the clutch pack to send torque to the front axle when a slip is detected (difference in axle speeds) in 4WD auto range In the other 4WD ranges, the clutches are locked to achieve 4WD ranges. There is no mechanical lockup, and the clutch pack has to deal with all the torque"



Do the the clutches so commonly getting smoked, Rigid Axle was working on a kit that replaces the clutch pack with a solid locker. I'm not sure what ever happened with that.

 

[Sherman Bird]

It's possible, but i havn't kept up with the design changes. I'd heard that the 5th gens (possibly Ram Classics too?), got a totally different transfer case that fixed this issue completely. But, i don't know for sure.


The initial resistance that creates drag on the front output, to get the balls to start up the ramps, is provided by part#29 in this diagram:

View attachment 553476


It's an electromagnetic coil. In 4 auto mode, when the computer detects and front/rear speed difference from the wheel speed sensors, it energizes this coil which creates drag on the ramp mechanism and causes the rear output to engage the mechanism, close the clutch basket (part 18) and transfer power to the front wheels.


In 4 lock, the coil is supposed to stay energized. Back in 2018/2019 when we on this forum were researching this, I seem to remember someone putting an amp clamp on the coil power feed and determining that even in 4 lock, it was only energizing the coil during front/rear wheel speed difference. Basically, doing the same thing as 4 auto. But, someone else did that test so i can't verify it's authenticity.

So, in 4 lock the engagement should be alot quicker, but it still requires the rear output to rotate in advance of the front output, in order for the ballramp mechanism to start working.

The way this case works mechanically, the more wear and tear you have on your TC, the longer it takes to engage the front wheels.

Probably why some guys who live in areas where they don't use it so much, don't mind the system. Guys who work in areas that do lots of climbing up mountains, like real mountains, where the elevation changes are measured in thousands of feet, definitely DO complain about it.

42 years ago, I was at High Island outside of Galveston Texas (east) with a church group. The beaches were much less crowded. A guy got his 2WD Chevy "Big 10" Pickup stuck in the sand. As he attempted to get out, he sank to the rear axle housing.... Game over. A "good Samaritan came by in a Jeep Wrangler CJ5 and tried to pull out the Chevy and sank front AND rear axles to the housing! Few minutes later, a K-5 4WD Blazer happened by and attempted to pull out this "train"! You guessed it, he also sank up to the axle housings!! Now, we had a convoy stuck.

Along comes a "Bubba" in a Ram Charger with a 440 and huge tires. He offers to pull out the entire "train" but for a price of a six-pack of Beer. The Church class "spokesman" got all religious and started to bloviate against alcohol and vices in general.

Said Bubba said that he was going on up the beach a mile or so for a while, and would check back. Meanwhile, all these church group guys were busting their collective fannies trying to dig these vehicles out, and failing miserably.

Aforementioned class "leader" commenced to slam the "Bubba" as to his life choices. Meanwhile, all the little workers were pressed to get these stuck vehicles out... "Who needs an immoral cuss" says the leader. The project continues to fail miserably each time they attempt to get these hopelessly stuck vehicles out.

By this time, "Bubba" can be seen approaching. He drives up and repeats his offer. So-called leader delves into A Jimmy Swagart inspired didactic tirade.

One of the other guys whose back was hurting came up, interrupted, and told the "Bubba" to just pull everyone out, and sent another parishioner to "get the damned beer". Said Power wagon hooked up to the "train" and pulled the entire set of vehicles out as though it was almost no effort.

I look back on that day from time to time and really get a laugh! However, THAT Power Wagon didn't have ANY computer nonsense on it. That "Bubba" got his beer... and as he drove off, he laughed really loud!

 

[Ken226]

Most of the guys back then really hated this transfer case, but personally, I think it is a really good case for most people and most common uses.

With this 44-44, your wife or daughter can use your truck in winter to run to the grocery store. She can drive around the dry, clean parking lot making as many tight turns as she want. Then when she gets home, you won't have to replace a busted transfer case.

It's only the guys using a light duty pickup for work stuff, like a Teal Jones employee going up Canyon Creek Rd in Glacier, WA to service logging equipment, or snowplowing the parking lot, who will have complaints.

 

[Kraken]

Here is an old article with good info, and some pics:

Snow plowing = BW 44-44 transfer-case failures - Transmission Digest

Experience we gain from solving problems generated in the transmission repair industry sheds light on various common failures and allows us to see trends that provide new products to solve design issues. From 2011 on, Dodge has offered Ram 1500 pickup trucks equipped with the BW 44-44 transfer...

www.transmissiondigest.com

From the article:
"If the shift command meets the software requirements, the externally mounted shift motor will shift into the desired range. The wet clutch is electromechanical design, using a clutch pack and a ramp-and-ball system to engage the clutch pack to send torque to the front axle when a slip is detected (difference in axle speeds) in 4WD auto range In the other 4WD ranges, the clutches are locked to achieve 4WD ranges. There is no mechanical lockup, and the clutch pack has to deal with all the torque"

Hmm I just sent them a Contact Us message asking about this. I'm sure they didn't as I can't find anything related on their site.