Check your owners manual for the proper use of your 4x4 system. It will drive extremely different on dry pavement than in slick conditions. In fact, it is possible to damage your truck driving in 4x4 on dry pavement.

The Auto setting will sense when your rear wheels are slipping and engage the front wheels, it is best used for varying road conditions where 4 hi might be a little much, but still slick enough where the rear wheels are slipping, or roads that might be snow blown where it alternates between dry and slick.

The low setting is something you will probably never use, it is only for the conditions that the 4 hi can't get you out of, and definitely not for road use.

If you don't have your owners manual, you can find an online version at the very bottom of the forum main page

 

Yep, on dry pavement, if you are in 4HI and try to turn sharply right or left, it will buck and you will have to give it gas to make it keep going....but that would be a bad idea. When in 4HI, the front wheels are locked in and by turning, one wheel will be turning significantly faster than the other, that creates the binding and it is putting a whole lot of pressure on the system. Can you do it, yes, but eventually, something will fail if you keep doing it. If you are on snow, ice or even sand and loose dirt, you can turn in 4HI and hardly notice it since the loose surface allows the wheels to turn at those different speeds without binding. Even driving straight ahead on dry pavement is not good in 4HI as there is always a slight discrepancy in turning ration between the front and rear wheels causing one set to turn slightly faster than the other, again causing binding between the two. However, the difference is not nearly as bad. If you accidentally run 20 or 30 miles in 4HI on dry pavement, you probably wont significantly hurt the drive train, but it isn't a good thing.
If you are on dry solid pavement, you should not be in 4HI under normal conditions. If you are on pavement that is covered intermittently with snow, ice, loose gravel , sand or whatever, then you would use the 4AUTO setting if your truck has it. The system should switch in and out of 4 wheel mode as conditions require. Some purists don't like the 4AUTO setting, others turn it on in the late fall and never turn it off until the snow stops in the spring.
Unless you are pulling stumps or doing some extreme 4 wheeling, you probably won't find a need for 4LO. Usually even 4HI is not needed for towing unless you are towing on other than paved clear roads.
As bksbigdogdoug says, check your owners manual, it has good guidelines on using your 4 wheel drive system.
There are links at the bottom of the main site page for downloading owners manuals but for some reason, they only go up to 2011. I am sure the information is the same in the 2011 manual as the 2012 however. Otherwise, I am confident that a search on the internet (maybe GM website) will provide a link to download your 2012 manual if you don't have a hard copy.
Good luck with your (new to you) Silverado. You are going to love that 4WD this winter in Michigan.

Here is a video I shot while pulling a stump in my yard this summer. 4HI vs 4LO

 

^^right idea, but you have it backwards. Basically in 4HI the wheel are locked into rotating at the same speed, so when you turn a corner the outside wheel needs to turn faster in order to travel the larger distance. Think of an old turntable - stick a penny near the middle and one at the edge. Both pennies have the same angular velocity, but the outer one has a higher linear velocity because it needs to travel faster in order to travel the larger distance around the record. OP, basically if you're turning all the way to the right in 4HI, the right wheel is closer the the centre of rotation, so your left wheel needs to turn faster, but it can't because it's locked at the same speed as the right wheel. Hope this helps

 

Yah, what n8dh said. Much better explanation of the situation.

 

I tried my best not to sound like a dick haha :lol: just helping a fellow 2012 Silverado LT owner out - nice work on the stump btw esox07

 

Thanks Fellas, that helps a lot. I thought for sure there was something wrong with my transmission at first. *also will there be a difference being in reverse when in 4Hi?

SO after reading everything, and seeing as *half snow and rain started coming down today here in Michigan, I would be best served to leave her in the Auto Setting, for the remainder of the year and through till dry pavement come spring time, with the exception, if its drop 6" of *stay on the ground* snow+ this winter, and actually have to switch to 4Hi.?

 

Yeah that's probably the best - leave it in auto until you really need it

 

Thanks !

 

Just one small note of caution while in AUTO mode >>> when on a slippery surface and when the rear wheels lose traction the FRONT wheels than are engaged and on that Transfer of Torque can cause a swingy condition in the rear <<< which is why I never use Auto mode >>> Either 2WHi or 4WHi now the fact my 2010 RCSB did not have a locker (G-80) in the rear may have contributed to this >>> I figure if you think you need Auto mode you might as well put it in 4w Hi and be sure >>>

 

^^right idea, but you have it backwards. Basically in 4HI the wheel are locked into rotating at the same speed, so when you turn a corner the outside wheel needs to turn faster in order to travel the larger distance. Think of an old turntable - stick a penny near the middle and one at the edge. Both pennies have the same angular velocity, but the outer one has a higher linear velocity because it needs to travel faster in order to travel the larger distance around the record. OP, basically if you're turning all the way to the right in 4HI, the right wheel is closer the the centre of rotation, so your left wheel needs to turn faster, but it can't because it's locked at the same speed as the right wheel. Hope this helps

If the front tires are locked into turning at the same speed when in 4HI, then why doesnt the front end wander when you floor the gas on snow/ice like the rear does when the locker engages?

 

When you say "wander", does that mean do a tail slide? It doesn't do that just because when your wheels are turned, they are trying to pull you in the direction they are pointed. If you floor it in 2WD in ice/snow when your wheels are turned, the front wheels don't pull you so the rear just swings around

 

Yes that's what I mean. Even if the wheels are pointed straight and you floor it, the rear breaks loose but the front still tracks straight. I would expect the driver to have very little control since none of the wheels have traction.

 

It still tracks straight because the front is pulling in the direction the wheels are pointed. If you're pushing, say, a snow sled from behind on ice,it's hard to get the front going in the direction you want...when you try to turn it the back end just kicks out right? Now pretend you're pulling the sled. Even though the front still has to traction, when you point it to where you want it to go, it "follows" you, so to speak. Now obviously if you are going at stupid fast *ground* speed, not wheel speed, the control is going to lessen quite a bit. Hope this helps - not a physics teacher but just applying what I've learned in HS and university haha

 

I live in Michigan too and never needed to actually put it in 4hi last year. Just kept in Auto and got me through anything I needed to get through.

 

I never really found any problems with using my Auto 4 on my '11 or the '04 it replaced.

If the roads are dry, I would leave it in 2 wheel drive though, might save on some wear and tear. And it really only takes a turn of the dial to engage the Auto 4 again if the roads do become slick. There are times in some of the country back roads that the wind will drive snow across the road in sections at a time, not enough for 4hi because there will be dry pavement in between, but enough that you might slide with 2hi when you do hit them, I find the auto works great with these circumstances. I do agree with Wayne in that if you are going to be on roads that are completely covered with snow, 4hi might be the way to go.

And don't be that you guy we always see every year, who thinks he has a 4x4 so he is invincible, that ends up being one of the first ones pulled out of a ditch. Use your head, 4 wheel drive means you can get moving quicker and keep traction longer, but will not do a Damn thing to help you stop.

 

^^True dat - makes me laugh actually when I see people just hauling a$$ in their 4x4 and then down the road they're in the ditch

 

Thanks Fellas, that helps a lot. I thought for sure there was something wrong with my transmission at first. *also will there be a difference being in reverse when in 4Hi?

SO after reading everything, and seeing as *half snow and rain started coming down today here in Michigan, I would be best served to leave her in the Auto Setting, for the remainder of the year and through till dry pavement come spring time, with the exception, if its drop 6" of *stay on the ground* snow+ this winter, and actually have to switch to 4Hi.?

Some do that but I dont think most do. I think mostly people that don't like to or really know how or when to switch between the different setting. A dealer told me that is what he does with his wife's truck because she can't figure out when to and when not to switch so he puts it in auto in the late fall and turns it off in the spring and tells her not to mess with it. I guess he was tired of finding out she has been driving in 4HI for the last 500 miles on dry roads.
My suggestion for the average truck driver is to switch as conditions dictate. The only time I use 4auto is when I am driving on roads where it goes from clear to snow/ice intermittently. Sometimes, driving down the road at 50 or 60 and having to reach down every mile or two when coming up to a snow drift across a road is not only a PIA but kind of dangerous as well. In one full wisconsin winter, I have probably traveled less than 100 miles in 4 auto.

 

Leave it in auto unless you get stuck then switch it to 4Hi, I ran it in auto all winter all conditions and never had an issue.

 

Hmmmm, I am surprised to see so many posts by those that extensively use the 4auto. Anyone out there want to chime in on selectively using 4HI for most conditions? I may have to rethink my winter driving strategy. I do know that some of the 4wd components stay engaged when in 4auto, even when it isn't actively in 4wd. Does that cause any excessive wear or fuel mileage impact?

 

Leaving it in auto will hurt your mpg. What auto does is it engages the front diff and then when the rear wheels slip it engages the transfer case to send power to the front diff.

So there is more drag hence the lower mpg. You'll also wear out the front diff oil sooner.

 

OK, so what strategy do you use in the winter 19trax95

 

Well my 95 didn't have auto so it was either 4hi or 2 hi haha.

But my 2001 has auto. I'll probably put it in auto when there's the chance of slick roads. If the roads are fully covered then I'll use 4hi.

My father used to leave his 2009 in auto all year round until I told him about the mpg loss. He now only uses auto in the winter. But he leaves it on all winter and put it in 4hi only when needed.

But generally speaking, if the roads are fully covered then I don't drive unless I have to. So I'll probably end up in either 2hi or 4hi and skipping the auto unless it's a mix of dry street and slick patches.

 

OK, that is basically my strategy as well. Thanks.
I hope the OP got his answers on turning in 4WD and then some.

 

Your GM owners manual requires you to be moving when shifting from 2H to 4H - and other info (won't detail it here)

maybe read your owners manual for shift sequence details ...

 

Cosmic Charlie: Who are you addressing with that statement?