4WD Lock or 4WD Auto?

[BossHogg]

It's exactly what it says it is: automatic 4 wheel drive. If it "automatically" engages on dry pavement, you're still driving a 4 wheel drive vehicle on dry pavement.

The transfer case feature you need to consider is the front axle is coupled through clutches and not gears like the RAM HD's. The clutches are forgiving and when in 4x4, the clutches will slip allowing axle syntonization.

The clutches in the transfer case is what allows the 4x4 auto mode permissible on all road conditions, albeit only the driveshaft is spinning. Also realize, in 4x4 auto mode, the front axle is only coupled to driveline power for the duration of the detected wheel slippage.

 

[CrispyBacon]

The transfer case feature you need to consider is the front axle is coupled through clutches and not gears like the RAM HD's. The clutches are forgiving and when in 4x4, the clutches will slip allowing axle syntonization.

The clutches in the transfer case is what allows the 4x4 auto mode permissible on all road conditions, albeit only the driveshaft is spinning. Also realize, in 4x4 auto mode, the front axle is only coupled to driveline power for the duration of the detected wheel slippage.

I thought it stayed connected while the gas pedal was pressed, or under a certain amount of torque from the engine. Like, it doesn't disconnect under a load, but if you let off the throttle it disconnects.

 

[vanila540i6]

How can I tell which transfer case I have?
2012 1500 big horn cc 4x4

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[CrispyBacon]

How can I tell which transfer case I have?
2012 1500 big horn cc 4x4

Sent from my SM-N910V using Tapatalk

Do you have a "4Auto" button, or just a "4Lock" button? That's the difference.

 

[mohemipar]

I thought it stayed connected while the gas pedal was pressed, or under a certain amount of torque from the engine. Like, it doesn't disconnect under a load, but if you let off the throttle it disconnects.

Pretty sure in "auto" mode it only stays engaged until the slippage is over. Regardless of pedal input or RPM. In "lock" (fake lock) it will hold in 4wd for a longer time and then also disengage.

Maybe in the lock mode there are other parameters that determine engagement. But I remember in my 1500, in auto I would feel it kick on and off really fast. Almost instantaneous. In lock mode it would get annoying at times on bad stretches when I could feel the truck slipping and waiting for the clutches to engage.

 

[WilliamS]

Pretty sure in "auto" mode it only stays engaged until the slippage is over. Regardless of pedal input or RPM. In "lock" (fake lock) it will hold in 4wd for a longer time and then also disengage.

Maybe in the lock mode there are other parameters that determine engagement. But I remember in my 1500, in auto I would feel it kick on and off really fast. Almost instantaneous. In lock mode it would get annoying at times on bad stretches when I could feel the truck slipping and waiting for the clutches to engage.

This is mostly correct. My truck seems to be hyper sensative in 4auto as it will power all 4 wheels with anything over 25% throttle input regardless of traction. It will unlock based on requested power. 4-lock does the same, but it will hold the 4x4 till I come to a stop. I do not need slip to engage 4auto in my truck and its something I can prove over and over. Ive seen the same model year in 4 auto in the same situations and it wont kick in till the rears are already digging in.

 

[mohemipar]

but it will hold the 4x4 till I come to a stop.

Ah, yes. I forget about this.

The system is honestly fine for the vast majority of situations. There were just times when on severe snowy roads or off roading when the system got on my nerves. Always got me through though.

 

[WilliamS]

Ah, yes. I forget about this.

The system is honestly fine for the vast majority of situations. There were just times when on severe snowy roads or off roading when the system got on my nerves. Always got me through though.

Same here, I've never been stuck, stranded or embarrassed pulling someone else out yet.

 

[mohemipar]

Same here, I've never been stuck, stranded or embarrassed pulling someone else out yet.

Yep. I remember yanking my buddy's car out of the ditch a couple winters ago. No sweat.

The gear system in the HDs is just peace of mind. You know you are always engaged. But the downside is, you dont have a nice auto mode when there is some light crap on the roads. I guess the weight helps make up for that a little.

 

[69GWC]

The only problem with the auto feature is the fact the clutch plates slip, the more they slip the more they wear and the more they slip.
It does seem that most that burn it up got the truck in a bind.

 

[loveracing1988]

Yep. I remember yanking my buddy's car out of the ditch a couple winters ago. No sweat.

The gear system in the HDs is just peace of mind. You know you are always engaged. But the downside is, you dont have a nice auto mode when there is some light crap on the roads. I guess the weight helps make up for that a little.

I just run it, it take a lot to actually break things in these trucks and the only situation where it binds is slow turns, if I have to I can just shift in 2wd and go.

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[smiley]

This feature is different by year as the older 4th gens like mine worked well. They used a different brand of transfer case I believe it is New Venture Gear aka NVG and it works awesome. Then they newer trucks with auto came with Borg Warner 4WD Auto transfer case that is not able to lock like the old ones and has had many complaints and been talked about at length on this forum. I just want people to be fair the old ones worked well!

 

[Murphy Slaw]

My "4 Auto" has worked fine the few times I've had to use it.

I'm not a Rock Crawler and expect it will do just fine.

 

[Jarhead57]

My "4 Auto" has worked fine the few times I've had to use it.

I'm not a Rock Crawler and expect it will do just fine.

Same here, its on most of the time in winter here.

 

[ej132]

What models does the 4wd auto start on? believe my '17 slt 5.7 only has 2wd, 4wdlock and 4low

 

[Cardhu]

What models does the 4wd auto start on? believe my '17 slt 5.7 only has 2wd, 4wdlock and 4low

BW44-45 is on the ST, outdoorsman (most configurations), sxt, slt and rebel

I think is also tradesman if your in the USA.

Generally is the cheaper transfer case, but i just so happens to be preferred in my books.

 

[VA10]

https://www.youtube.com/watch?v=6lMgtYnSjvA

At 4:53 the BW 44-44 (atuo tc) works quite well here with the crappy SRA tires. There are also plenty of other videos of the 44-44 handling some fairly extreme scenarios I know many us would never put our trucks through.

I know a handful of people who drive RAMs that have the auto TC. All of them seem be happy with it (at least no regrets about it). So far in my experience gently throttling until the rear wheels slip is key. Because, once the rears slip with almost barely any throttle applied the truck is in 4x4. Not ideal for some situations. yes.- but I have yet to come across a situation where the 44-44 has not worked in my favor.

The 44-44 will works very well as long as you understand it how it engages. I have my 14' outdoorsman w/ the 6'4 bed which has the auto tc. I am off road about 2-3 a week. It preforms well. never had an issue yet with performance or getting unstuck.

The auto TC I think because the standard TC on Big Horns and up.

 

[Danno]

There is no difference in the 4auto or 4lock. It's the same exact thing. Transfer case doesn't lock anything in, it's a play on words.

 

[VA10]

There is no difference in the 4auto or 4lock. It's the same exact thing. Transfer case doesn't lock anything in, it's a play on words.

I believe 4hi requires less slippage to engage the front wheels. Or at least that seems to be the case on my truck. Other than that it behaves the same as 4 auto.

https://www.youtube.com/watch?v=GiVFBAb5iCk

@ 7:05 ^ there is a good example of 2wd vs 4 auto vs 4 lock on a icy grade with a trailer. Watch the rear wheels when in 4 lock vs 4 auto. When in 4 lock the rear wheels barely slip before the fronts engage. VS 4 auto which take about a 1/6th of a rotation before the fronts start to pull.

I am not saying I am correct that the 4 hi requires less slippage. But I feel my truck behaves this way. What also leads me to belive this is that I seen videos that somewhat confirm this. This video being one of them.

 

[ej132]

So if my truck doesnt specifically have 4 auto listed on the dial it does not have it correct?