First of all, English is not my first (or second) language, especially when it comes to the techical details around cars, so my apologies if I don't get it right, and I hope the meaning gets across anyway.


As winter is approaching, I've started using "Auto 4WD" instead of "2WD".


From my experience with other vehicles, I expected it to kick in the 4WD when needed only. However, it behaves more like a 4WD vehicle with the differential locked at all times. For example, when I make a tight turn (such as while parking) on a non-slippery surface, the front wheels will kind of "skip" or "jump", due to the different rotational speeds required.


Is this to be expected, and should I switch to 2WD when doing tight manouvres, or is something wrong? If something is wrong, is it a "biggie" or is it an easy fix?

 

Auto locks the front hubs, but not the center. If the computer senses a speed difference it locks the transfer case. (or maybe it locks the xfer case, but not the front hubs, it's been a while).

Unless you actually have snow on the road, leave it in 2WD.

 

This is actually bad/wrong advice. Auto 4WD is designed specifically for variable conditions like wet/dry/snowy roads.

If you are driving on snow-covered streets, you should have it in 4Hi.

When you are in Auto 4WD, the truck should behave just like it's in 2WD. There should not be any binding or scrubbing when you make sharp turns. If this is happening in your truck, then it indicates a problem

When the computer senses the rear wheels slipping, it engages the transfer case and sends power to the front wheels. It will then disengage the transfer case after a short time when there is no more slippage.

From the owners manual:

 

Did the op change tire size?

 

I'd like to use 4WD Auto for snow-less winter conditions, since "black ice" (a thin, almost invisible layer of ice on the road) is quite common here.


I have the original tires, so no tire size change.


Could the reason be in the bold text below?



In other words, the front diff is locked, but power is not sent to it?

 

Partially correct. Power is not being sent to the front axle unless the computer detects rear wheel slip.

But the front hubs are locked, not the differential. The front axle has an open differential. And since the transfer case is not engaged, all four tires can spin separately when in Auto 4WD.

Again, Auto 4WD is supposed to be used in varying conditions. It's like putting the system in standby. If your truck is behaving like it's in 4Hi when it's set to Auto 4WD, then you have a problem with your system.

 

Let me clarify; by "snow", I meant any less than ideal traction material.
I said snow since that seemed to be the material of concern.

With the front hubs locked, you may notice more noise than usual, and more steering force may be required, even if the transfer case isn't locked (engaged). Perhaps the transfer case was locked when you performed this turn. Your fuel economy will also be lower in 4WD Auto. But I'd also rather pay fuel than end up off the road.

My experience is from my 09. My 1995 Tahoe did not have an 'auto' mode. Nor did any of my Jeeps.

When was the last time you changed the front diff fluid?
I changed mine at 100,000 miles and it came out like grey water...

 

So, to sum this up, the general consensus is that it's time to go the the workshop and have it looked at?