Is it bad to run your truck in “Auto 4wd”?

[Michael Cook]

On 3/23/2019 at 6:17 PM, UGADawgs said:

I think 4 auto keeps the transfer case in open diff mode, so it should be safe. However, if you're on dry pavement, not sure the value doing it. Mostly some mpg loss. If it was raining, I'd definitely use it.

I have a 2014 GMC SIERRA SLT Z71 Crew Cab, and I use the all wheel drive in rainy crappy weather, due to working out in North County Southwest Washington and with a good set of all season tires together  its a God send.

[JimCost2014]

52 minutes ago, Michael Cook said:

North County Southwest Washington

Welcome to the site.

 

Have lived in Washington for over 90% of my life, and have no idea where you are at. Grew up in Burlington, so very very familiar with the north part of the state, live in Auburn now, so know the middle part, and have 2 house on the Long Beach Peninsula, so am now up to speed on the southwest part of the state. 

[Randy Lahey]

Old thread, but I was wondering about this as I always keep my '99 Sierra 2500 in Auto pretty much all winter long here in central Canada.  There is packed snow (and lately sheer ice from the wind) on the road sometimes from Oct to April.  It's currently -36C with about 4 feet of snow in my front yard.  The grader doesn't do a deep clean until spring.  No such thing as 'dry pavement' in the winter here 

[Snakes709]

23 hours ago, Randy Lahey said:

Old thread, but I was wondering about this as I always keep my '99 Sierra 2500 in Auto pretty much all winter long here in central Canada.  There is packed snow (and lately sheer ice from the wind) on the road sometimes from Oct to April.  It's currently -36C with about 4 feet of snow in my front yard.  The grader doesn't do a deep clean until spring.  No such thing as 'dry pavement' in the winter here 

I live in Edmonton so i have the same driving conditions. Will it hurt the truck? No, its what its made for. But if the driving conditions are good, ie dry pavement, why would you keep in 4auto? It just puts more wear on the parts and uses more fuel as now there is more driveline drag. If the road is dry or very little snow, 2wd is what i run in. Only time i use 4auto is if im on ice or hard packed snow. Had it onto as there was alot of black ice on the road and the median/ramps filled with cars. Only saw it kick in once when i made a turn and gave a little to much gas. I only use 4hi if its really bad out or im in deep snow. 

Edited December 6, 2022 by Snakes709

[Z45]

On 3/25/2019 at 10:05 AM, z1boss said:

I've always ran my trucks in 4wd auto.  No issues at all.  I've noticed that the gas mileage isnt really affected either based on my testing.

Me too, when roads are bad in winter.  All the naysayers don't know what they are talking about for the most part. I have had several trucks with this and always use AUTO in the winter and when when the roads are wet (raining).  That's why its there!  If you are never going to use it, then why buy a 4wd truck.

Quote

AUTOMATIC TRANSFER CASES
The last category is a combination of 4WD and On Demand AWD. These transfer cases have a 2HI, Auto-4WD, 4HI, 4LO and Neutral position and would fall in the general 4WD category. This transfer case has the operating characteristics of both an On Demand AWD and a Part-Time 4WD system depending on the mode selected. This transfer case uses a clutch pack to allow for a difference in speed between the front and rear axles in the Auto-4WD mode. In the 4HI or 4LO modes, there is no allowance for the difference in speed between the front and rear axles.

 

Edited December 6, 2022 by elcamino

[kmeleon]

Auto is absolutely awesome as soon as your tires get a bit of wear and start slipping when making turns from a stop in the rain. I use it Alot in that scenario. In the dry, I turn it off. 

[Ronjon]

Anyone know if lift size or type affects the 4AUTO? Say spacers vs coilovers. 2.5" vs 3" vs 4"? Some lift/level kits say to not use this function anymore. I plan on doing 3.5" total coilovers this weekend and Belltech assured me using 4AUTO would be fine still (snow and rain).

[RedLT]

17 hours ago, elcamino said:

Me too, when roads are bad in winter.  All the naysayers don't know what they are talking about for the most part. I have had several trucks with this and always use AUTO in the winter and when when the roads are wet (raining).  That's why its there!  If you are never going to use it, then why buy a 4wd truck.

 

 

I've read a few threads on 4WD systems and keep coming across comments "don't use it unless you have to" and "it's going to wear out the system"  and . I'm like.. then what the hell is the purpose of 4WD?? I get it.. to not use is on a pretty sunny day, I've only used it a couple times on rainy days but I'll keep reading to educated myself to be sure I'm doing the right thing.

[Muddturtle1231]

18 minutes ago, RedLT said:

 

I've read a few threads on 4WD systems and keep coming across comments "don't use it unless you have to" and "it's going to wear out the system"  and . I'm like.. then what the hell is the purpose of 4WD?? I get it.. to not use is on a pretty sunny day, I've only used it a couple times on rainy days but I'll keep reading to educated myself to be sure I'm doing the right thing.

The gravel road in front of my house has a very steep incline, and I have seen (and heard) many 4WD trucks refuse to use 4WD for some reason.  They absolutely destroy my road.  I use my Auto AWD every time I go home.

Edited December 7, 2022 by Muddturtle1231
Added a sentence.

[Snakes709]

5 hours ago, RedLT said:

 

I've read a few threads on 4WD systems and keep coming across comments "don't use it unless you have to" and "it's going to wear out the system"  and . I'm like.. then what the hell is the purpose of 4WD?? I get it.. to not use is on a pretty sunny day, I've only used it a couple times on rainy days but I'll keep reading to educated myself to be sure I'm doing the right thing.

The more a part gets used, the more it wears down. 4auto uses clutches to activate 4wd when it detects slip. 4wd is meant to be used on low traction situations. Have you ever tried to turn sharply with 4hi or 4low on dry surfaces? It can damage the drivetrain. The clutches help minimize that so it can be used when its dry. But my question is, why would you? If the driving conditions are ideal, why would you need anything other then 2wd?  

[RedLT]

3 hours ago, Snakes709 said:

The more a part gets used, the more it wears down. 4auto uses clutches to activate 4wd when it detects slip. 4wd is meant to be used on low traction situations. Have you ever tried to turn sharply with 4hi or 4low on dry surfaces? It can damage the drivetrain. The clutches help minimize that so it can be used when its dry. But my question is, why would you? If the driving conditions are ideal, why would you need anything other then 2wd?  

 

Sure.  As I've stated, I have used it on rainy condition wet roads not pretty sunny days.  I guess that's what you mean by "ideal condition".  I drive 2Hi (2WD) 99.5% of the time.

[Snakes709]

13 hours ago, RedLT said:

 

Sure.  As I've stated, I have used it on rainy condition wet roads not pretty sunny days.  I guess that's what you mean by "ideal condition".  I drive 2Hi (2WD) 99.5% of the time.

yea thats what i meant. 

[Z45]

Most who own a 4wd truck really don't need one.  This is what AUTO is for....I would spinning tires all day without it.

Edited December 8, 2022 by elcamino

[KARNUT]

I worked on pipelines and utility lines. I drove 4x4s. I used it more on wet roads than on the pipelines. 

[Z45]

We had 4x4 pu's and suburbans on our GPS teams...

Edited December 8, 2022 by elcamino