2 or Auto

[Martin Samson]

I would like to have a clarification on the Auto mode on the 4X4 knob. when AUTO is selected, is it a real All Wheel Drive or the more a 4X4? Can I drive on asphalt over 60mph on dry pavement??

[truckguy82]

I would like to have a clarification on the Auto mode on the 4X4 knob. when AUTO is selected, is it a real All Wheel Drive or the more a 4X4? Can I drive on asphalt over 60mph on dry pavement??

You can drive as fast as you want in auto.

 

It should be labeled "AWD" instead of "auto 4wd"

[Silverado Steve]

No, 4wd Auto is not the same as All Wheel Drive. With All Wheel Drive power is applied to all 4 wheels all the time in most systems. I believe Subaru's AWD systems work differently, but the concept applies. With 4wd Auto, the front hubs are locked and when there is wheel slippage detected, power is then applied to the front diff. In a All Wheel Drive system, there is a center diff that adjust toque to the wheels that keeps driveshaft binding from happening. A standard 4wd system doesn't have this and this is why you will feel wheel hop when turning the steering wheel in 4wd on dry pavement. There are many posts on this topic, if you want to read more in depth, try doing a search on "4wd" or "All Wheel Drive" It was discussed way in depth here a few months back.

[Silverado Steve]

Unfortunately, that is incorrect. 4wd Auto is not the same as All Wheel Drive and their characteristics shouldn't be confused.

 

You can drive as fast as you want in auto.

 

It should be labeled "AWD" instead of "auto 4wd"

[truckguy82]

No, 4wd Auto is not the same as All Wheel Drive. With All Wheel Drive power is applied to all 4 wheels all the time in most systems. I believe Subaru's AWD systems work differently, but the concept applies. With 4wd Auto, the front hubs are locked and when there is wheel slippage detected, power is then applied to the front diff. In a All Wheel Drive system, there is a center diff that adjust toque to the wheels that keeps driveshaft binding from happening. A standard 4wd system doesn't have this and this is why you will feel wheel hop when turning the steering wheel in 4wd on dry pavement. There are many posts on this topic, if you want to read more in depth, try doing a search on "4wd" or "All Wheel Drive" It was discussed way in depth here a few months back.

actually you are wrong

 

our systems have a clutch activating 4wd system and it's used in the auto setting.

 

When in auto, there is nothing locked even when it's engaged. While it's not exactly like awd. It's far closer to awd than it is to what it names suggests...which is automatically engaging 4wd

[truckguy82]

Unfortunately, that is incorrect. 4wd Auto is not the same as All Wheel Drive and their characteristics shouldn't be confused.

 

Yeah they kinda should, I made a thread about this exact topic and we had a very knowledgeable GM tech chime in on the difference. It is very very similar to AWD

[Silverado Steve]

Incorrect. a true All Wheel Drive system has a center torsion differential that manages the torque going to all 4 wheels all the time. Our truck is no different then a 4wd system with a smart front diff. It doesn't manage torque to all 4 wheels all the time. In the auto setting, the clutch pack in the front diff has 10% power applied and the front hubs are locked, but full power is not applied. All it does it applies power to the front wheels and removes power once traction is no longer needed. Two totally different systems.

 

actually you are wrong

 

our systems have a clutch activating 4wd system and it's used in the auto setting.

 

When in auto, there is nothing locked even when it's engaged. While it's not exactly like awd. It's far closer to awd than it is to what it names suggests...which is automatically engaging 4wd

[txchevy4ever]

Auto 4WD is in no way related to All Wheel Drive.

[BSME1115]

Yeah they kinda should, I made a thread about this exact topic and we had a very knowledgeable GM tech chime in on the difference. It is very very similar to AWD

That GM tech was not correct, It is not at all the same as an AWD system. Steve was correct. The hubs are locked and then the transfer case is not engaged until slippage is detected via a dog clutch

[truckguy82]

Incorrect. a true All Wheel Drive system has a center torsion differential that manages the torque going to all 4 wheels all the time. Our truck is no different then a 4wd system with a smart front diff. It doesn't manage torque to all 4 wheels all the time. All it does it applies power to the front wheels and removes power once traction is no longer needed. Two totally different systems.

 

A center differential only manages torque to the front and the back

 

A smart front diff? I think you mean a smart center diff. Our front diffs are just regular open diffs

[Silverado Steve]

Yup, I'm familiar with that post and if my memory serves me right, he strictly said that our system is not a true All Wheel Drive system.

 

Yeah they kinda should, I made a thread about this exact topic and we had a very knowledgeable GM tech chime in on the difference. It is very very similar to AWD

[truckguy82]

That GM tech was not correct, It is not at all the same as an AWD system. Steve was correct. The hubs are locked and then the transfer case is not engaged until slippage is detected via a dog clutch

The hubs? hubs don't lock and unlock when you have a center diff

 

this isn't 1995

[Silverado Steve]

A center differential only manages torque to the front and the back

 

A smart front diff? I think you mean a smart center diff. Our front diffs are just regular open diffs

I think it would help if you googled difference between All Wheel Drive and 4WD. Our front diff has a clutch that senses wheel slip and the transfer case will aplly up to 50% power. Modern All Wheel Drive systems apply power to all 4 wheel a 4WD system does not. In the case of Subaru, their system can cut power to one wheel and transfer power to another, our system does not. In reality, all our system does is takes the judging of when to turn the knob to 4HI

[Silverado Steve]

A center differential only manages torque to the front and the back

 

A smart front diff? I think you mean a smart center diff. Our front diffs are just regular open diffs

I think it would help if you googled difference between All Wheel Drive and 4WD. Our front diff has a clutch that senses wheel slip and the transfer case will apply up to 50% power. Modern All Wheel Drive systems apply power to all 4 wheels a 4WD system does not.An All Wheel Drive system also also allows each wheel to turn at different speeds. In the case of Subaru, their system can cut power to one wheel and transfer power to another, our system does not. In reality, all our system does is takes the judging of when to turn the knob to 4HI

[truckguy82]

Yup, I'm familiar with that post and if my memory serves me right, he strictly said that our system is not a true All Wheel Drive system.

 

yup, but it's pretty damn close, so close it could be labeled awd

 

We have a front diff, a rear diff which operate the same no matter what.

We also have something very similar to clutched center diff.

In auto4 the systems changes the front and rear torque split through the clutch. There is NOTHING that is locked or binding, all 4 tires can spin independently of each other. This is almost exactly how an awd system works.

In 4wd hi, the front and rear axles are locked