GM HD Trucks Many with AWD instead of 4WD

[RobWNY]

Where snow and mud isn't an issue, you can have a 4X2 truck as your tow vehicle, but here in the Northeast, 4X4 trucks are the norm. Now GM is offering AWD instead of 4WD in many of their HD trucks. At least up here, I'm seeing most HD trucks with the AWD option. I'm not so sure that's a good idea in my neck of the woods. What are your thoughts?

[parker_rowe]

Thermoguy wrote:
This is OK and a nice piece of mind, but a truck needs a true 4x4 transfer case.

But...it is a true 4x4 transfercase.

It's like an evolution of the full-time 4x4 transfercases, with the benefit of only engaging the front axle when it slips via computer controlled clutches, rather then spinning them all the time via a viscous coupler or center differential.

Auto=full time 4x4
2H=2WD
4H=4 Lock or 4H
4L=4L

[Thermoguy]

Terryallan wrote:

mkirsch wrote:
AWD and traction control probably would have worked well in that situation.

Traditional 4x4, even with a limited slip or locking rear diff, is at best a THREE wheel drive system, and that one front wheel that's spinning doesn't bring anything to the party except some slung mud. If you've got open diffs front and rear then you're down to a TWO wheel drive system, and the wheels that get power are always the ones with the LEAST traction.

AWD doesn't let you get to that point. If you're stuck, you're truly stuck because all four wheels have no traction. You're not stuck because the two wheels that might be able to get a little bite are just sitting there while the other two spin.

AWD will cover 99.99999% of cases, except maybe rock crawling or mud bogging. If you're doing those with a brand new production vehicle, I'd call your sanity into question.

I have seen a AWD stuck spinning each wheel, then taking power from the spinning wheel, until finally. It took power from all the wheels. and it just sat there doing nothing.

This right here is the problem with AWD - I have a Ford Explorer - work vehicle. The first snow, going up a hill, the wheels started to slip, all wheels started to slip. It didn't matter how much I pushed my foot down, it wouldn't go. Started to roll backwards. I had to play with the AWD functions, found one where it turns of the limited slip. Then I could spin the wheels until I could power up the hill. Went and bought studded tires as soon as the weather allowed me to get out. A truck with this feature would be useless unless you can turn it off.

From other posts, it sounds like a similar feature on a Yukon I used to have, Auto was a 4WD feature that would engage the front if it started to slip. Not sure if it worked, but I would turn it on if the roads were slippery but not enough for true 4WD. This is OK and a nice piece of mind, but a truck needs a true 4x4 transfer case.

[parker_rowe]

Huntindog wrote:
My new truck has 4 choices: Auto/AWD, 2WD,4Hi,4 Low

Thats what I though.

Not what I would consider "AWD" thats any lesser than the old part time cases.

Just has the extra feature of automatically engaging the front wheels when slip is detected if you want.

If you don't like it, put it in 2WD, and use 4WD when you need it.

Put some tape over the Auto button so it doesn't offend.

[Grit_dog]

RobWNY wrote:

gattorgetter wrote:
What trim package? I can find one at the plant tomorrow and look

It's a Crew Cab LT Duramax. PM sent with the info

NICE Truck!
GMC or Family Truckster model (Natl Lampoons vacation...)?

[Grit_dog]

gattorgetter wrote:
I build these trucks.... it is either 2 h 4l/4h. Or those 3 plus the auto.... depending on trim pkg

Let's not ruin the fantasy or reason to complain with real facts....lol.
I questioned this 2 pages ago as Ida bet a weeks pay that ALL the HD 4x4 trucks of any of the big 3 still have 2 speed transfer cases.

However, the peanut gallery just kept clamoring on about how they like AWD or hate it because it aint like pappys old Willys...

[RobWNY]

gattorgetter wrote:
What trim package? I can find one at the plant tomorrow and look

It's a Crew Cab LT Duramax. PM sent with the info

[gattorgetter]

Message me whatever info you have... vin) and i can look it up on my end

[gattorgetter]

I will look but i think that is that has the auto... i looked for a solid hour while they were going down the line....
No awd... the 4th button is auto

[gattorgetter]

What trim package? I can find one at the plant tomorrow and look

[RobWNY]

gattorgetter wrote:
I build these trucks.... it is either 2 h 4l/4h. Or those 3 plus the auto.... depending on trim pkg

Maybe you built the one I'm considering. It's got the LT trim package

[Huntindog]

My new truck has 4 choices: Auto/AWD, 2WD,4Hi,4 Low

[gattorgetter]

I build these trucks.... it is either 2 h 4l/4h. Or those 3 plus the auto.... depending on trim pkg

[RobWNY]

The truck I'm considering is a Chevy 2500 HD with the 11,350 GVWR and upgraded RAWR and other towing capabilities. It's "in transit" from Michigan to Buffalo. What that means exactly, I don't know and neither does the new truck sales manager. He has requested updates every 5 days from GM. It's been "in transit" over a week now. In all fairness, it's probably on a truck carrier going who knows where and could even be in Canada somewhere. (shortest route from Flint, MI to Buffalo, NY is through Canada). On the Chevy website it says it's 4WD, on the dealers website it says AWD and on the window sticker from the dealers website it says 4WD. The sales manager says its a 4WD model as well. Who knows at this point. It might get here and I'll find out it's a 4 cylinder Chevy Sonic.

[parker_rowe]

time2roll wrote:
If it applies the brakes to any wheel to transfer the torque then it is weak and is for moderate conditions at best. JMHO

I have TrueTrac limited slip front and rear along with the locked low range as needed. Works great for what I need.

The brake thing works fine. Not a locker but it works.

People have been doing it for years manually.

I have had a tire hanging in the air and the brake based torque biasing system worked perfect.

Can someone point me to these supposed AWD transfer cases in HD GM trucks?

All the ones I see are true 2 speed cases. They may have an Auto Mode with computer controlled clutches, but they also have dedicated 2WD, 4WD, and 4WD low ranges.

I know some of the Denali SUV's may have AWD single speed cases, but these are still true, robust transfer cases, that will do the job just fine for 90% of people. They are nothing like what people envision when thinking of the "AWD" mini SUV's.

[time2roll]

If it applies the brakes to any wheel to transfer the torque then it is weak and is for moderate conditions at best. JMHO

I have TrueTrac limited slip front and rear along with the locked low range as needed. Works great for what I need.