4 wheel drive??

[orviskid]

this is my first 4x4 truck. if trucks aren't actually 4 wheel drive, where all 4 tires are engaged at the same time. whats the difference between auto and 4 high on my truck??

[RyanbabZ71]

A simple answer is 4 high is always "on" (engaged). Auto 4wd turns on when needed

[scooby5121]

Another point is you have one drive wheel in the front, one drive wheel in the rear, and if you have a locking diff in both then you have true four wheel when engaged!!!

Basically saying.

Scooby

[Wires]

Really you only get 3-wheel drive. All fronts are open-diffs, so if one tire starts to spin in the front, you lose the other. The locker in the rear will lock up though.

 

You can't steer if the front had a full locker.

[scooby5121]

The older solid axle front ends on the blazers and such had that option for front lockers

[Wires]

The older dodges did too. I don't know of any modern full size GM's though. I asked about my GMT-800, and the diff shop said it was a bad idea for street use. Only really useful for hard-core offroad/rock climbing.

[HEMICAT]

Auto can be used anytime, right? 4-high can't be used on dry pavement.

[RyanbabZ71]

Auto can be used anytime, right? 4-high can't be used on dry pavement.

 

It can be but highly not suggested

 

 

Ryan

[chev1guy]

You can always add a locker to the front. Like someone above said unless you plan to do some hard core wheeling, you will not need it.

[scooby5121]

4 High on the straight highway with snow covered sections is ok....

4 Automatic is for the unasure driver.... my wife !!! mostly all 4 wheel drive mid size vehichles are equipped like this option.

[Z45]

The older solid axle front ends on the blazers and such had that option for front lockers

 

 

I have owned new GM 4x4's going back to 1975 and I never heard or seen of a locker in the front axle. I don't think they existed. Like was said, a locker in the front is a dangerous thing on highway. A locker in the rear can also be dangerous and thats why you will find the disengage at around 20 mpg and will not enage over that speed. Its a safety issue.

[rotti]

Yeah, GM has never offered a front locker as factory option. Maybe, on edit, H1 Hummer??

You can get an after market front Eaton E-locker for the current GM 3/4 ton trucks.

Do it your self install: http://www.ctwillis....cker/index.html

 

The current Jeep Rubicon has selectable front and rear lockers.

[scooby5121]

Elcamino they do exist

[MikeNH]

Another point is you have one drive wheel in the front, one drive wheel in the rear, and if you have a locking diff in both then you have true four wheel when engaged!!!

Basically saying.

Scooby

 

 

 

No such thing as a drive wheel. An open differential will send power to the path of least resistance but on normal driving that will be about equal side to side and front to rear so all wheels will see some power transfer on a tractive surface. On snow/ice/whatever, you might very well get the one wheel spinning like mad and the other going nowhere but the spinning wheel is not the "drive" wheel, it is simply the one on the surface with the least friction.

[kstruckcountry]

With a SFA you could spool the front axle and just unlock hubs when not using 4x4. But GM has never had offered it.