4x4 Engaged Question

robertbick · January 9, 2009

With all the snow we are having here in Upstate NY, my 2500HD is usually in 4X4 especially when plowing. It just seems that there is a lot more resistance when driving in 4X4 then in 4X2 (going down the road not plowing). It's probably just me but it was much harder to notice the difference in my previous vehicle which was a Toyota Sequoia SUV.

Driving with the plow on the front also could be the reason, it's just that it rolls much better in 4X2 then in 4X4. I can also "feel" a significant difference when in 4X4.

Do you guys notice a difference?

Jennabear · January 9, 2009

Yep, that is the point of 4X4 more traction with all 4 wheels trying to work.

robertbick · January 9, 2009

Yep, that is the point of 4X4 more traction with all 4 wheels trying to work.

Wow! Thanks for the tip.

VMax2007 · January 9, 2009

Robert.....Just so ya know...

http://www.gm-trucks.com/forums/index.php?showtopic=88216

robertbick · January 9, 2009

Robert.....Just so ya know...

http://www.gm-trucks.com/forums/index.php?showtopic=88216

Thanks! I have not been on for about a month & didn't know.

VMax2007 · January 9, 2009

Robert.....Just so ya know...

http://www.gm-trucks.com/forums/index.php?showtopic=88216

Thanks! I have not been on for about a month & didn't know.

That's what I figured.

Jennabear · January 9, 2009

Yep, that is the point of 4X4 more traction with all 4 wheels trying to work.

Wow! Thanks for the tip.

I assume you already understand the physics on pushing (4X2) and pulling (4X4):

The product of average net force and change in time is called Impulse. You need impulse to get your 2 wheels moving, and a lot more impulse to get all 4 moving. So it takes more time for 4 individual wheels to get impulse and thus momentum.

robertbick · January 9, 2009

Yep, that is the point of 4X4 more traction with all 4 wheels trying to work.

Wow! Thanks for the tip.

I assume you already understand the physics on pushing (4X2) and pulling (4X4):

The product of average net force and change in time is called Impulse. You need impulse to get your 2 wheels moving, and a lot more impulse to get all 4 moving. So it takes more time for 4 individual wheels to get impulse and thus momentum.

The point of my question was with regards to more resistance in 4X4 then in my previous vehicle. I realize their is more impulse required to get all 4 wheels moving. It's just not as smooth as other 4X4's I have owned. But then again it might have something to do with the extra weight of the plow on the front. This is the first plow I have had plus the first HD truck.

asilverblazer · January 9, 2009

All four wheels are getting the same amount of power eventually, and all are encountering differnt forms of resistance, especially front to rear, where there is no differential to accomadate these resistance differences. This means in some cases the wheels are working to overcme them selves and obstacles at different rates creating more resistance. Perhaps some of the other 4x4's you have owned had some sort od differential capabilities with in the transfer case that the truck does not.

Resistance I am talking about would be like on fresh snow. The front tires have to smash through/pack down the snow in there path. The rear tires do not, they ride in the path already forged by the front.

dewfpo · January 9, 2009

Part time 4WD vehicles are not designed to be driven on high traction surfaces like streets in 4H or 4L. Especially with the weight of the plow on the front, your compressing those front tires (smaller rolling diameter) and they are trying to spin faster than the rears just driving straight down the road. Forget about in a turn.

Only use the 4WD when you need it.

DEWFPO

robertbick · January 10, 2009

The last two answers make a lot of sense. Thanks!

ZZ327 · January 10, 2009

Its also because you say its your first 3/4 ton truck. You can definitly feel the difference in ride and turning between that and a half ton.

Youll feel that resistance also with your plow off, if you drive on a snowy or icey road that has some dry spots. Or even when youre turning

ursandal · January 11, 2009

I just returned from a 70 mile trip and was in 4wd the whole time. Roads were completely snow covered traveling btwn 30-40 mph.. I too can tell a difference in the truck when in 4wd, definetly more resistance, but sure footed that's for sure. More noticable in this HD compared to 1/2 ton trucks I've owned in the past. I've just put it off to heavier truck and drive train.