How does AUTO 4WD work/what does it do?

[Rader]

Wouldn't this preclude it from shifting into 4Lo while rolling as well?

It depends, with the Trans in N rolling very slowly would rotate the 4 lo sliding gear in the T case and help mesh the gear teeth. Rolling to fast with the transmission in N would preclude shifting without some serious grinding.

EDIT Opps! Muddy12 you beat me to it.

 

[madweazl]

Thanks for the info; learned quite a bit in this thread. This is our first 1/2 ton truck (owned three F250s prior to this) so it never occurred to me that there would be a transfer case that performed in this manner.

 

[wascrash]

I'll add my .02 to the list of disappointed Ram 4x4 owners as well. Like most people, the biggest thing that aggravates me is the misleading way it's labelled.

Being honest with myself, I'm on rutted single track once or twice a month tops, when I go out to my spot in the woods to shoot or hunt. I live in the city, work in the city, etc. While I would have preferred the reassurance of true 4wd, the auto is what I need 97% of the time. It's looking like a pretty slick winter so far in Ohio, and I've had no trouble in the past with the 4 auto. I do have to live with a health fear of the mud though.

The only time the 4wd has let me down was in my own yard, when the truck slid back down my hill in wet grass. Wouldn't have been a problem at all except it slid back into the trailer. Pissed me off pretty good, but even if 4 wheels had been turning the whole time, it still probably would have slid. Tires are still the thing that connects the truck to the surface, and for most people like me, that's probably still the critical failure point. Unless you're out bogging regularly, or rock crawling, the 44-44 is probably satisfactory. I still would have liked to have understood it when I bought it, and it peeves me that I can't have both AWD functionality and true 4wd, but I've come to accept it.

I was very disappointed to find out my bighorn had this 44-44. Although it does well in snow. I just want to know that if I go offroad and get stuck in the mud in the summer hear that rocking my truck 10 minutes is not going to alarm an transfer case over heat or burn out my clutches. Ford has the good transfer case with auto. Not the ram sorry to say. I should have got the 5 liter f-150.

 

[Machria]

I was very disappointed to find out my bighorn had this 44-44. Although it does well in snow. I just want to know that if I go offroad and get stuck in the mud in the summer hear that rocking my truck 10 minutes is not going to alarm an transfer case over heat or burn out my clutches. Ford has the good transfer case with auto. Not the ram sorry to say. I should have got the 5 liter f-150.

Yeah right! Tell that to my checkbook after I replaced my tranny 3 times BEFORE hitting 100k on my F150!! No thanks.

 

[Ken226]

Don't be disappointed in the 44-44, it's disadvantages are outweighed by it's advantages for most of us.

I've been completely through the 44-44, as well as it's smaller brother the 44-05, and it works well, until you damage it with all the testing.

(Don't hold the brake and throttle at the same time. The computer isn't programmed to accommodate this maneuver)

I use mine in snow, ice, mud and occasionally some light rock crawling, in the North Cascades in WA State. And it works great in all those scenarios.

Where it rocks!:
4 auto on multi-surfaces ice to dry, etc.
4 auto in mud
4 lock, in mud
4 lock crawling up loose rocks
Icy hills
Deep snow

Where it sucks:
Backing a trailer in mud
Backing up in general
Putting in 4 low and testing in snow
Anytime you try to outsmart the computer

It's clutch isn't a typical slipping type clutch. It's a full lock clutch. The clutch operates in 2 possible states. Off of on. The engagement is soft, but can be violent if you try to outsmart the traction control.

In 4 auto the computer activates the clutch any time the wheelspeed sensors detect the rear wheels spinning faster than the front wheels.

In 4 lock the clutch is continuously activated.

When the clutch is activated, either by the computer, upon detecting wheelspin, or by the user in selecting 4lock, the ballramp clutch can be thought of as a ratcheting clutch, without the clicking sound.

When avtivated the ballramp clutch makes the transfer case behave like a bigass ratchet. It's a one way torque transfer device.

The transfer case input shaft drives a screwlike ballramp. It's very coarse (full compression. Of the clutch in about 60 degrees, ( 3 balls and 3 ramps spaced 120 degrees apart, with each ramp occupying 60 degrees of Arc), forces the clutch plates into compression. The more you mash the throttle, the harder the clutch plates are forced together.

Basically, the rear wheels, in turning, will force the front wheels to turn too.

But, the one-way ratcheting nature of the ballramp, means that the front wheels will always be allowed to turn faster than the rear wheels, when, for example, your going around a turn.

The electromagnetic device that initiates the ball ramp engagement produces some pressure in the clutch plates though. So, if you driving in a circle in 4 lock, you'll notice a little drag/binding. But, not nearly as much as a totally gear driven transfer case.

 

[LouM]

Don't be disappointed in the 44-44, it's disadvantages are outweighed by it's advantages for most of us.

I've been completely through the 44-44, as well as it's smaller brother the 44-05, and it works well, until you damage it with all the testing.

(Don't hold the brake and throttle at the same time. The computer isn't programmed to accommodate this maneuver)

I use mine in snow, ice, mud and occasionally some light rock crawling, in the North Cascades in WA State. And it works great in all those scenarios.

Where it rocks!:
4 auto on multi-surfaces ice to dry, etc.
4 auto in mud
Bull
4 lock, in mud
Bull
4 lock crawling up loose rocks
Icy hills
Deep snow
Bull

Where it sucks:
Backing a trailer in mud
Backing up in general
Putting in 4 low and testing in snow
Every where except a mostly dry road

Anytime you try to outsmart the computer

It's clutch isn't a typical slipping type clutch. It's a full lock clutch. The clutch operates in 2 possible states. Off of on. The engagement is soft, but can be violent if you try to outsmart the traction control.

In 4 auto the computer activates the clutch any time the wheelspeed sensors detect the rear wheels spinning faster than the front wheels.

In 4 lock the clutch is continuously activated.

When the clutch is activated, either by the computer, upon detecting wheelspin, or by the user in selecting 4lock, the ballramp clutch can be thought of as a ratcheting clutch, without the clicking sound.

When avtivated the ballramp clutch makes the transfer case behave like a bigass ratchet. It's a one way torque transfer device.

The transfer case input shaft drives a screwlike ballramp. It's very coarse (full compression. Of the clutch in about 60 degrees, ( 3 balls and 3 ramps spaced 120 degrees apart, with each ramp occupying 60 degrees of Arc), forces the clutch plates into compression. The more you mash the throttle, the harder the clutch plates are forced together.
No it does not, the more traction the rear has the more force it will allow to be transmitted to the front axle, AND the less traction at the rear the less force (torque) will be available to the front, so if the front has good traction and the rear not the front will not have the same potential and you can be stuck.

Basically, the rear wheels, in turning, will force the front wheels to turn too.

But, the one-way ratcheting nature of the ballramp, means that the front wheels will always be allowed to turn faster than the rear wheels, when, for example, your going around a turn.

The electromagnetic device that initiates the ball ramp engagement produces some pressure in the clutch plates though. So, if you driving in a circle in 4 lock, you'll notice a little drag/binding. But, not nearly as much as a totally gear driven transfer case.

This is a worthless transfer case once a person gets off the mainly clear paved roads.
!1) even accepting your theory of operation this case can't transfer more torque to the front axle then the rear axle is accepting;
if the rear axle is in a very low traction situation the front axle will not receive anymore then the rear,
so if the rear is spinning easily say 10 ft lbs of torque it is not going to clamp the clutch therefor the electric portion of the clutch is all that is going to try and drive and it will slip and overheat and not move your truck so even with 400 ft lbs available from the engine multiplied by the transmission and then multiplied by the transfer case will not be applied to the front. So something as simple as crossing a ditch with the rear on ice and the front on a high traction surface ( clean pavement, frozen bare dirt) you can be completely stuck if it needs more torque then the rear can apply to the axles.
2) This t-case does not provide holdback from the front axle when going down grade
3) The damned computer disengages the mickey mouse clutch when the transmission is placed in park
4) every time this case is labeled as lock it is a damned lie, period​

 

[chrisbh17]

With all of the "extras" in the truck (traction control, limited slip rear diff) I feel like its hard to tell where those stop and 4WD actually starts.

I put my truck in 4 auto today so I could hop a curb in reverse....I know I made it over the curb without issue, but Im not sure if 4WD had anything to do with it.

Maybe thats the idea behind the 4 Auto xfer case....Im not a fan of what has been found to be "normal" operation, but I havent been stuck with it either (at least not yet)

I would be interested to see if the xfer case from the 5th gen could be adapted to 4th gen, assuming it works better than the 44-44.

 

[ColdCase]

Where it rocks!:
4 auto on multi-surfaces ice to dry, etc.
4 auto in mud
4 lock, in mud
4 lock crawling up loose rocks
Icy hills
Deep snow

Where it sucks:
Backing a trailer in mud
Backing up in general
Putting in 4 low and testing in snow
Anytime you try to outsmart the computer

Good description, but I have to disagree with you. In practice this case sucks big time in mud deeper than say 1 inch. It sucks big time in partially plowed mixed highway where you are faced with slush mounds. It sucks when there is a huge difference between front and rear traction. It sucks starting out on a steep snow covered or icy driveway. About the only thing it rocks in is keeping a spouse from damaging the driveline by driving around a dry mall parking lot in 4 lock

That being said, it may be adequate for most. A 4x2 with limited slip, some weight in the bed works just as well for most. But I buy 4x4 because I want something effective in the above conditions.

 

[mohemipar]

I would be interested to see if the xfer case from the 5th gen could be adapted to 4th gen, assuming it works better than the 44-44.

Seems like the 5th gen will have a much better case.

 

[chrisbh17]

Seems like the 5th gen will have a much better case.

Maybe? It seems like the last bunch of Borg Warner cases in use in the RAM are mysteriously undocumented. Not sure the 5th gen one will be any different other than everyone saying its new and improved.

 

[Ken226]

if the rear axle is in a very low traction situation the front axle will not receive anymore then the rear,​

This is incorrect.

A hypothetical thought experiment:

Let's assume that a situation as you describe is occurring.

The rear wheels are set on rollers and are free to spin. The front wheels are on dry pavement. 4 auto is selected.

As you press the throttle, the rear wheels begin to spin on the rollers.

The computer immediately detects the rear wheels spinning faster than the front wheels and sends current to the electromagnetic actuator, which applies a compressive force to the clutch basket.

At this point, the friction between the clutch plates causes the ballramp to force the clutch plates into compression and drive the front wheels.

The traction between the front wheels and the road surface retard are retarding movement of the front wheels, increasing the force exerted on the clutch plates by the ball ramp.

As you further mash the throttle, the engine produces more torque, and the ballramp forces the clutch plates together harder. All (100%) of the engines torque is transferred to the front wheels. The rear wheels will not rotate at a higher speed than the front wheels. When the front wheels begin turning, pulling the truck along, the rear wheels will be rotating on the rollers at the same speed.

This is fact. You don't have to take my word for it. Just disassemble your transfer case and you'll see how it works with your own eyes.


I'll draw a simple ballramp actuator and clutch in CAD and try to post it here. It'll help visualize how this system works.

 

[mohemipar]

Maybe? It seems like the last bunch of Borg Warner cases in use in the RAM are mysteriously undocumented. Not sure the 5th gen one will be any different other than everyone saying its new and improved.

Well, I have read that there will continue to be two cases available. The BW 48-12 and BW 48-11. The 48-11 might continue along with the phony locking mode, but I read it has been substantially upgraded internally. Will have to wait and see I guess.

The 48-12 will probably be the real locking case and will go in the Rebel or maybe come on trucks as an option (part of an offroad package?). Hopefully. That is what Ram should have done on the 4th gen 1500.

 

[Podcast]

I can only speak to my experiences with this T-case.

I had a '13 and now have a '17 both Bighorns. Both trucks acted the same so theoretically both operated mechanically sound and as designed. I had new limestone poured on my very steep driveway last fall. I waited for it to rain and then took my truck up and down the drive to compact the limestone into a solid hard surface. If I spun my wheels it dug into the driveway therefore creating holes so I used 4WD to slowly crawl up and down my drive. Both 4-auto and 4-lock did not perform well at all. I would constantly spin my rear wheels each attempt to travel up the driveway. In fact, the 4-auto seemed to engage much quicker than 4-lock. I ended up using 4-low. I cannot say if the 4WD clutch system worked any differently however I more-so believe the low gear caused my rear tires not so spin regardless of 4 wheel engagement which allowed me to complete my task of leveling my drive.

The way the 4WD system on these auto T-cases works is disappointing depending on your use. Like others have said, I do like how well it performs while driving down the road in snowy condition etc however when I want 4WD I want it to actually be 4WD instantly and all the time.

I can compare my auto system to my fathers and brothers Express models and those models actually do LOCK into place obviously lacking to auto functionality. I wish a guy could get that system on a Bighorn....

 

[chrisbh17]

.....
I can compare my auto system to my fathers and brothers Express models and those models actually do LOCK into place obviously lacking to auto functionality. I wish a guy could get that system on a Bighorn....

I find it ironic that RAM, Ford, etc use these cases in the HIGHER than base trims. Like they are implying its better, somehow, but in reality it might not be the case.

Could you imagine plunking 70K on an F150 to get this xfer case?

 

[Machria]

I find it ironic that RAM, Ford, etc use these cases in the HIGHER than base trims. Like they are implying its better, somehow, but in reality it might not be the case.?

That's because people like myself buy the "higher than base trims" as you call them. I have a Limited, and enjoy and kindof need (high end job... and need a high end vehicle) all the bells and whistles. I'm also lucky enough to be able to afford it. But 80 or 90% of the time, I really should just be driving a regular old high end sadan (Caddy, Audi, BMW....) back and forth to work on regular streets and hwy's. Then the opther 10 or 20% of the time jump in a truck to carry stuff (fishing/boating gear, hunting, skiing...). But since I really don't have the space or want to waste the extra money to purcahse, maintain and store 2 vehicles for myself, I instead buy a high end truck that has an inside like an executives sadan, but has the utility and features of a 4x4 truck I can also use.

So for me, I the transfer case works just fine. I just got back from Vermont skiing last weekend, most of the 6 hour trip on dry roads, with a few icy or snowey patches thrown in when getting off the highway for a stop. Then when driving around killington, VT and in muddy/snowy/icy driveways and parkinglots and back roads, I had 4 Auto to use. At one point, we went up a very steep hill that was a pure sheet of ice and snow, so I popped it in 4 lock, worked perfect.

Am I rock climbing with the truck? no! am I mountain climing with the truck or whatever they do out west? No!

So RAM and the other companies probably know exactly what they are doing when they pair high end trucks (upper trim levels) with lower end t-cases. They are cattering to folks like me, which are by the way, the MAJORITY of their customers.

Could you imagine plunking 70K on an F150 to get this xfer case?

NO THANKS!! See my post above! My F150 required 3, or $10k of tranny's to be REPLACED in short order! I don't care if ther Tcase is GOLD plated, they can stuff their tcase up where the sun don't shine!

 

[CostaRam]

AFAIK: The Ram has also a kind of a diff lock, braking the spinning wheel to transfer torque to the still standing wheel.
This system is used also in the last series Land Rover 90/110/130 and it is certainly better than no diff lock,
but the noises and extensive use of brake lead to faster wear and tear of the brake pads and disks.

The 44-44 sucks also in soft sand, but this is probaly the last used underground, but it's mine.
Someone stated that the Explorer had/have the same transfer case but i never had any problems with my 2002 Explorer.
I did a lot of crazy stuff with my poor Explorer and this includes:
5 times Rio Bongo crossing (wide and approx 2 ft deep)
nnn times miles and miles driving on hard sand
nn times driving on soft, deep sand
driving up the steep, slippery jungle dry mud road with a fully loaded car and 4x4 dead (a 2002 problem)
If i would immagine to do that with my 2011 Sport .... I better don't immagine ...
I tried soft, fine grain sand in Panama last year and got almost stuck and the banging, grinding, squealing noises from the ABS, axles and transfer case sounded not very healthy...
I have to admit that i was not checking if 4x4 is somehow usefull under rougher conditions but to be honest i did not expect that the system is for (snowy) street use.

Chris

 

[chrisbh17]

That's because people like myself buy the "higher than base trims" as you call them. I have a Limited, and enjoy and kindof need (high end job... and need a high end vehicle) all the bells and whistles. I'm also lucky enough to be able to afford it. But 80 or 90% of the time, I really should just be driving a regular old high end sadan (Caddy, Audi, BMW....) back and forth to work on regular streets and hwy's. Then the opther 10 or 20% of the time jump in a truck to carry stuff (fishing/boating gear, hunting, skiing...). But since I really don't have the space or want to waste the extra money to purcahse, maintain and store 2 vehicles for myself, I instead buy a high end truck that has an inside like an executives sadan, but has the utility and features of a 4x4 truck I can also use.

So for me, I the transfer case works just fine. I just got back from Vermont skiing last weekend, most of the 6 hour trip on dry roads, with a few icy or snowey patches thrown in when getting off the highway for a stop. Then when driving around killington, VT and in muddy/snowy/icy driveways and parkinglots and back roads, I had 4 Auto to use. At one point, we went up a very steep hill that was a pure sheet of ice and snow, so I popped it in 4 lock, worked perfect.

Am I rock climbing with the truck? no! am I mountain climing with the truck or whatever they do out west? No!

So RAM and the other companies probably know exactly what they are doing when they pair high end trucks (upper trim levels) with lower end t-cases. They are cattering to folks like me, which are by the way, the MAJORITY of their customers.



NO THANKS!! See my post above! My F150 required 3, or $10k of tranny's to be REPLACED in short order! I don't care if ther Tcase is GOLD plated, they can stuff their tcase up where the sun don't shine!

My comment was meant more about the fact that the more you spend the "cheaper" your transfer case seems to be. Not the fact that they make and sell "higher than base" trims. I 100% agree on buying what you want, exactly what I did (Big Horn). At the time I just assumed the t-case was somewhat normal, but it seems like it isn't. I havent had my truck that long so it may very well be a non-issue for me, at least until the clutches wear out.

The Big Horn trim and higher CANNOT get the tried and true 44-45 t-case from the factory, but Id be interested to see if someone ever swapped one in, instead of buying replacement clutches.

 

[Ken226]

The 44-44 is a more complex, more expensive case than the 44-45. Chrysler used that criteria in deciding that it is the -premium- transfer case, included in the higher end models.

But, for some, the higher complexity and non-standard function makes it a lemon.

It's understandable that many feel this way. If the areas it's lacking, happen to be the areas they need standard type performance, they are lett down.

I like the 44-44. Not everything about it, but the overall.

Now that I understand it's strengths and weaknesses, I find it rather easy to avoid the weaknesses and exploit the strengths.

I may as well learn and use it accordingly. I'm not dropping 40000.00 on a new truck anytime soon.

Perhaps I'm just lucky, but in 4 lock, when I take off on mud, ice, snow, whatever, all 4 of my wheels start spinning at the same time, every time.

 

[indept]

Keep in mind as many have said here that most of us don't rock climb or go through 2' deep mud etc. Ram engineers selected this so the average driver can put it in 4wauto and get through 6" of snow without thinking about it. My previous DD was a 2000 Grand Cherokee with the Select a Trak TC so I too thought my new Ram had the same or similar when I saw the Auto, Hi , & Low selection options. Ram should advertise better and focus on the Rebel for off road. It would be nice if they had a Torsen front diff like the F150 offers to boot. They do offer a locking rear in the 2019's so thats a step forward.

 

[MT Hillbilly]

Reading all this "I'm disappointed by the RAM's transfer case" has me wondering. What do some of you expect from a transfer case that offers auto 4x4? You can not have gear engage drive in a system that offers auto 4x4, it has to be clutched.

My 2013 RAM is not my first rodeo with 4x4s, it is my first Chrysler product. Before the RAM I drove GM's and Ford's over the years. They all had 4x4 auto and they all worked parallel to my RAM.

I live mid-Michigan, 2.3 miles off paved roads on a private dirt road that is never plowed. My auto 4x4 has never failed me in the snow, ice, sleet, mud or whatever else Michigan roads can through at me. And, I have never burned up a xfer case either.

I think what is really broke here is RAM's inability to document how the system actually works leaving folks to start making assumptions leading to disappointments.

If you think you really want a locking transfer case, go drive a RAM HD and enjoy your steering binding. I would love to have the refinement of my 1500's transfer case in my 3500.

Just my 2 cents, but yes, for 90 percent of the time here in Northern Montana the system is good to great, however.. if your literately 14 miles from the nearest paved road, and even further from help, that 10 percent becomes more important. Yes, I could buy the heavy duty one but.... then you loose the reasons you bought the 1500, better gas mileage, better ride etc. like I said 90 percent of the time it is exactly what I want, being able to actually lock it would be nice for that 10 percent. Don't get me wrong, this is my third ram, and I will buy another I love these trucks, but there is room for improvement! I wish I could afford another rig for hunting and playing.. so that option is off the table for me.