4H vs Auto

[tsbond]

Not sure if this belongs here not a problem for say but was just wondering if there is an explanation of 4H vs Auto 4. I like Auto because parking lots don't grab the tires and make that stuttering grabbing of the tires trying to park. Probably silly questions but was just wondering how the auto decides when it is time to use 4 wheel drive? Curiosity mostly

[davester]

There is an excellent explanation of the feature in the owners manual.

[tsbond]

Thanks for nothing. I will go read that instead of asking humans what they think is better with experience. Sorry to waste your time to post the obvious.

[CamGTP]

It's 2WD until the rear slips, then it's 4WD. That's the basic's of it.

 

Pretty much never use 4H on pavement and try to do turns, it's not good for the truck.

[tsbond]

Ah OK. I live in Alaska so is half the year on snow or ice and seemed to work well. Was just wondering about the design of it. Drives as well as my 4Runner I traded in without Auto and in 4H all winter.

[CamGTP]

There are many 4X4 systems out there. That's why some can be left in 4H all the time without damage because the transfer case is designed for that. This also why AWD vehicles don't bind going through parking lots.

[davester]

28 minutes ago, tsbond said:

Thanks for nothing. I will go read that instead of asking humans what they think is better with experience. Sorry to waste your time to post the obvious.

That is different from what your original question was: "was just wondering if there is an explanation of 4H vs Auto 4".

[tsbond]

Well then just poor wording then. I mean why even post if you are just going to say read the 400 page manual?

[JimCost2014]

51 minutes ago, tsbond said:

Not sure if this belongs here not a problem for say but was just wondering if there is an explanation of 4H vs Auto 4. I like Auto because parking lots don't grab the tires and make that stuttering grabbing of the tires trying to park. Probably silly questions but was just wondering how the auto decides when it is time to use 4 wheel drive? Curiosity mostly

Welcome to the site.

 

Tire slip, if one tire (wheel) looses traction, usually around 100 revolutions faster than the others, the system will send power to the opposite, front or back to "lock" them up.

 

Then as it senses things are good again, it resorts back to rear wheel drive, where 4HI locks the front and rear wheels, so they have to spin at the same speed.

[tsbond]

Thanks that makes sense was just wondering how it worked basically. That explains it much better.

[Rocz3cqg]

1 hour ago, tsbond said:

Not sure if this belongs here not a problem for say but was just wondering if there is an explanation of 4H vs Auto 4. I like Auto because parking lots don't grab the tires and make that stuttering grabbing of the tires trying to park. Probably silly questions but was just wondering how the auto decides when it is time to use 4 wheel drive? Curiosity mostly

Basically the Wheel Sensors in the rear will determine if the Transfer Case engages the front axle due to slippage detected on the rear wheel. So on dry surfaces, no slippage occurs on the rear wheels, therefore the transfer case will not engage the front axle. With a slippery  surface, the rear wheels will slip causing the transfer case to engage the front axle.

[tsbond]

I think it is a good system just the first one I have owned with auto. Used to turning 4h off and on all the time. Works very well in the snow when getting up over small hills etc. Must be fast response to conditions. Thanks for the post. Just wanted to make sure it was safe system to use on the highway etc.

[dieselfan1]

[tsbond]

You crying bro?

[davester]

18 minutes ago, tsbond said:

Well then just poor wording then. I mean why even post if you are just going to say read the 400 page manual?

Well, it's just 5 pages of that manual, so it should take you less than an hour.