Can driving in 4WD auto on dry roads damage my truck?

[Rick Tate]

This morning. I noticed that my 2019 GMC Sierra SLT was in 4WD auto mode. I didn't put in 4WD auto mode. Any idea how my truck switched from 2WD to 4WD auto? Can driving in 4WD auto on dry roads damage my truck?

[Leopardtech]

Auto will not cause damage, it doesn't switch into 4wd until wheel slippage is detected. Driving in 4wd hi or low on dry asphalt can certainly cause damage though. 

Edited December 10, 2019 by Leopardtech

[rkj__]

When I took delivery of my truck, it was in 4 auto, and I did not notice until I had a few hundred km on it.  No harm done. 

[MY164X4]

Heavy rain here in Tennessee, I used the 4x4 because my truck like to slide in the rain in 2wd.

BFG K02 tires, 5.3L have a lot of torque.

Sent from my SM-N976V using Tapatalk

[OnTheReel]

There is a slight fuel economy penalty, as well as some added wear and NVH involved with running in Auto 4x4 ALL OF THE TIME since the front end is engaged.
 

In your case, you didn’t, and aren’t going to damage anything because the power goes through a clutch to allow for wheel speed differences (so there is no binding). That said, over the long haul it’s best to only use it when needed. Wet roads, or the sort of mixed snow cover we sometimes get here are perfect scenarios. It’s also handy if you need to launch in a hurry to merge, or to gap that Mustang in the other lane...

[oldmann]

It will not cause damage but it will wear out parts.  I believe the transfer case will be engaged, but not the driveshafts or visa versa.  

[RaisedByWolves]

2 hours ago, OnTheReel said:

There is a slight fuel economy penalty, as well as some added wear and NVH involved with running in Auto 4x4 ALL OF THE TIME since the front end is engaged.
 

In your case, you didn’t, and aren’t going to damage anything because the power goes through a clutch to allow for wheel speed differences (so there is no binding). That said, over the long haul it’s best to only use it when needed. Wet roads, or the sort of mixed snow cover we sometimes get here are perfect scenarios. It’s also handy if you need to launch in a hurry to merge, or to gap that Mustang in the other lane...

With my 2001 I liked using it to **** with sports car guys in sketchy conditions.

 

Wet pavement, leaves, dirt/debris on the road.

 

With this truck its not even fair.

[BigBadSierra]

Autotrac is a clutch based system and will only apply pressure and turn the front tires if it detect slippage.

 

So no real issues running it when ever you desire...

[rah7777777]

Doesnt it always send like 10 or 15% up front? Even on perfect dry days?

 

 

I drove my trucks first 5 or 6,000 miles in auto before I even learned what the hell it was.

After trying to do donuts in the rain and not being able to, I started researching this "Auto" to find out it was more of a real AWD setup, always sending some power to the fronts. Now it is hands down my favorite feature! And I didnt even know it had it when I bought it. 

[Bigguy214]

Your good I leave mine in auto 100 percent of the time with my last 3 silverados and nothing has ever happened to trans or anything.It is like all wheel drive when you leave it in that mode.The only time it kicks in is when the computer senses wheel slipped he.

[tbarn]

Ask most GM techs what they think about running Auto 4WD all the time. Most will say hell no.

[econometrics]

I run mine in 4A when it rains here in DFW. It’s great peace of mind to know I won’t slip around under acceleration. 
 

When it dries up again, I put it back in 2H. 

[madconcept]

I’m a firm believer in only running it during questionable road conditions.

I’m on my 3rd truck now with this feature and I always notice extra drivetrain noise with auto 4x4 on.

I’m not a fan of listening to those extra noises on a day to day basis and fuel is expensive so taking a slight fuel economy hit isn’t in my best interest.

[AlaskaErik]

Yesterday I saw my winter neighbor's 2015 Escalade for the first time.  I noticed the selector was in the Auto position and mentioned it to him.  He had no idea about how it works.  I'm guessing it's been in the Auto position for at least the 30,000 miles he's put on it.  With a 6.2L that uses premium, I have to wonder how much extra gas he's burned.

[AlaskaErik]

1 hour ago, madconcept said:

I’m a firm believer in only running it during questionable road conditions.

I’m on my 3rd truck now with this feature and I always notice extra drivetrain noise with auto 4x4 on.

I’m not a fan of listening to those extra noises on a day to day basis and fuel is expensive so taking a slight fuel economy hit isn’t in my best interest.

I've had a 2001 Sierra and still have a 2016 Silverado and a 2019 Silverado and I've never noticed any extra drive train noise when in Auto.  And I've got very sharp hearing.