Auto 4x4 Mode?

[jemurray]

I noticed today that somebody (most likey my fishing partner) turned on my Auto 4x4 mode on my 2005 Z71. It never felt like it was engaging going down the road, but I traveled ~20 miles with it on (at least). I switched it back to "2wd" mode as soon as I saw that it was on. Anybody know how Auto 4x4 works? I would think that it would only engage upon sensing some slippage.

[BlueTahoe]

I believe auto 4x4 engage the front hubs all the time and then engages the transfer case when any slipping occurs. This won't hurt anything! I actually engage auto for about 10-15 miles onces a month just to work all the components in the front diff so they don't sit idle for months.

 

In the winter I drive in auto 4x4 allot. You probably wouldn't hurt anything at all if you drove all the time in auto. It would take thousands of miles and even then they there wouldn't be problems just additional uneeded wear on the front diff internals.

 

I had an explorer before this. I know - I admit it - I used to own a ford. The explorers only options were auto - 4hi & 4lo.

[Kania2k1]

I usually also drive with in Auto mode in the winter, and if it's raining and I'm on the interstate. Back when I have the crappy stock tires on the truck, I could break the rear loose a lit easier, and I tested the Auto trac one day in the rain. At a stop light, I mashed the gas when it turned green, and it spun for a second, then the front hooked up, and I was off!!! Let off the gas pretty soon after that. I actually drive in 4hi if there is any snow on the road way, or has been recently.

[Bish]

I noticed today that somebody (most likey my fishing partner) turned on my Auto 4x4 mode on my 2005 Z71.  It never felt like it was engaging going down the road, but I traveled ~20 miles with it on (at least).  I switched it back to "2wd" mode as soon as I saw that it was on.  Anybody know how Auto 4x4 works?  I would think that it would only engage upon sensing some slippage.

 

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Auto engages the hubs and the transfer case applies power to the front when it detect wheel slippage.

 

I only use Auto when the road is wet or slick. It is great for when you hit a roadside puddle and the front just kicks in instead of pulling to the side. On dry pavement, I still believe you can bind the front end and cause wear or worst case damage so I never use it on dry pavement.

[DEV1ST8R]

It drives in normal 2wd until it senses that it needs the extra 2. When I bought my truck the dealer actually did a demonstration with me. We went to a gravel pit and floored it in normal 2wd. . .threw rocks everywhere and didn't move very well. Did it in auto 4wd, skipped for a second, then took off like we were on pavement. It's pretty awesome.

[jemurray]

Thanks for all the info guys!! My last vehicle (a Ford Escape 4x4) only had "Auto" and "high", but it was a much smaller vehicle.

[GLOCKM22]

I have never understood the aoto 4x4 feature. it is like maybe i will need 4 wheel drive. everone knows on here when the need 4 wheel drive whether it is snow, wet or whatever. isnt that what 4 wheel hi is?? i think auto 4x4 is a waste and they should spend the money on a better feature.

[asepgrad98]

i think auto 4x4 is a waste and they should spend the money on a better feature.

 

maybe you can hit the 4x4 button in 0.2 secs when slippage occurs but most cant

[DEV1ST8R]

Why drive in 4x4 hi all day long when you only experience actual slippage maybe 1/100th of the drive? It makes perfect sense. Leave it in auto 4wd and you don't have to wonder, "hmm, do I or don't I need to use 4wd today?" It'll use it when you NEED it. . .by the time you realize you need it, it's too late - you're sliding.

[GLOCKM22]

When you are sliding--ie(skidding), It doesn't matter if you have 20 wheel drive. I learned that in 10th grade driver's ed. black1500.

[GLOCKM22]

Asep--What difference does it make if it takes someone an hour to hit the 4 wheel drive when slippage occurs?

[burgundyz71]

I agree auto is awsome.

[J-rod]

I agree auto is awsome. 

I don't use it as often as I should, but it is quite handy when the roads are wet (not much ice and snow in south MS!!!). It gives you the extra traction you need when you need it without the extra power loss through the drivetrain (transfer case) when you don't! It also seems to engage much faster than 4-hi. I suppose due to how the transfer case works when in auto as opposed to 4-hi???

 

And GLOCKM22, I think the other guys were just trying to say that it's a great way to prevent skidding / sliding / spinning in the first place without having to ride around in 4-hi all the time. Certainly there are cases where it would just make more sense to use 4-hi because you know you'll need it the whole time (icy roads for example ), but that's not always the case.

[killerZ-71]

AUTOTRAC 4x4 is awesome, period. only those that have not had it before

would most likely bad mouth it. IT IS A GREAT FEATURE TO HAVE!!!!

[nhproxr]

Autotrac is a good feature in my mind. Especially if the wife takes the truck when its slippery. I find it to be perfect a couple days after a snowstorm when there is a lot of dry pavement on main roads yet still snow and ice in parking lots or side streets. This way I don't have to worry about her wondering if she needs 4x4 or not and wearing out driveline on dry pavement.

 

It operates by using ABS sensors to detect wheel slip. One thing not mentioned here though is to not use it when towing a trailer. There are clutches in the system that can wear much quicker when pulling a heavy load in autuotrac.