Auto AWD vs 4WD high

[Sightfisht]

Noticed that axles bind when turning in auto AWD. I don’t have limited slip or a locker and I’m surprised that I’m getting this? What’s the difference between Auto AWD vs 4WD high in this case? Thx

 

[StuartV]

I don't think it's supposed to do that.

I will try to remember to try this in mine when I go out.

 

[thebluegoat]

I thought the way it worked on the 4th gens was if you put it into 4WD Auto it wouldn’t engage the front shafts until the truck detected rear wheel slip. Maybe something has changed for 5th gens

 

[StuartV]

I thought (think) on the 4th and 5th gens, the front axles are hard-connected in the wheel hubs. They turn all the time, even in 2WD. I think in Auto 4WD, something inside the transfer case engages when you need power to the front. In 2WD, the transfer case never sends anything to the front wheels.

 

[SpeedyV]

Noticed that axles bind when turning in auto AWD. I don’t have limited slip or a locker and I’m surprised that I’m getting this? What’s the difference between Auto AWD vs 4WD high in this case? Thx

Auto 4WD is looking for differences in rotational speeds between wheels before engaging. By definition, your wheels are turning at different speeds when turning. This means you can engage the system even on dry pavement while turning. My ‘03 Sierra 1500HD exhibited similar behavior.

I thought the way it worked on the 4th gens was if you put it into 4WD Auto it wouldn’t engage the front shafts until the truck detected rear wheel slip. Maybe something has changed for 5th gens

From another forum: “The reason for any decrease in mileage while in 4 auto is due to the front axle disconnect has engaged the front driveshaft. There is still nothing happening inside the transfer case (until slippage occurs).”

 

[Biga]

I know I have felt some some binding in 4wd Auto with my 2019, I did not have this with my 2014 Ram. Last I heard there was supposedly some kind of TSB in the works from Ram to address this but I have not heard of a fix yet.

 

[StuartV]

I just went out and tried mine. I put it in Auto 4WD and did a few slow, full lock turns (on dry pavement). Radio off. Windows down. I could not hear or feel any binding.

 

[troutspinner]

In the winter, I tried both modes in a few inches of snow. I could tell a difference with auto only engaging when I would purposely try to fishtail it. In 4wd, I felt the heaviness of the front wheels engaged.

Fast forward to spring and towing my boat. When at the ramp, I started with putting it in auto and it felt no different than 2WD. I think I've watched too many ramp fails on YouTube so I changed and started putting it in 4WD. I now feel the binding when making turns into the parking area after unloading the boat and that makes me feel a little more confident if I were to ever slip on the ramp as I know it doesn't need to "think" in a bad situation, it's already prepared. I also engage the axle lock as well, I have it, I might as well use it.

In short, if you're not feeling a difference, I would have the dealer look at it as you could literally destroy your axles if it is failing in auto the same as you could in 4WD driving on dry pavement.

 

[HKP7PSP]

Mine also feels a bit tight in 4WD Auto on turns, usually just with some clutch noise as I'd describe it. The way I see it, when you are turning, all four wheels are turning at different speeds (inner vs outer wheels, front and back) - this makes the transfer case sense slippage, and hence the application of torque to the front as well which causes the binding sensation. Also keep in mind if you run the truck in 2WD primarily, your rears might exhibit more wear than the front, which further changes the speed between front and back / side to side. This very well might be corrected with a flash update to the system, if and when one comes available.

In 4WD High, things feel much different - it is totally locked up. Driving on a muddy field at a winery, I could feel the 4WD system binding in High vs Auto, so I know they are operating differently.

 

[kenthelawnguy]

my 2019 ram just started to do this after working flawlessly for months. started to feel like in 4 wheel drive when making turns and now while driving home in the rain the other night as i was pulling into my drive i got a 4 wheel drive system overheating msg flash up on my dash for a couple seconds. going to have dealer look at when i take in for recall work and just leave it out of 4 auto until then.
with putting 21000 miles on my truck already, i have a pretty good feel for what feels normal and not normal.

 

[Sightfisht]

Auto 4WD is looking for differences in rotational speeds between wheels before engaging. By definition, your wheels are turning at different speeds when turning. This means you can engage the system even on dry pavement while turning. My ‘03 Sierra 1500HD exhibited similar behavior

Thx, great answer.

Dealership said it was normal, but couldn’t really tell me how AWD is different from 4WD high.
My wife’s Durango RT has full time AWD and there’s no binding