Very rainy day here yesterday with sleet so decided to pop it into Four High for the first time. Couple things and questions:

Seemed to have negligible impact on mileage, I was surprised. I suspected a drop, but nope...basically the same on a 200 mile round trip: 22 mpg.

BUT...here's my question...noticed when I pulled into a McD's for breakfast and went through drivethrough it was somewhat hard to turn and felt like the front end was kind of "grinding" to make the turn at low speed.

Any ideas?

 

It probably wasn't slippery enough to use 4x4 when you were turning sharp to go through the drive through.

 

You were binding up the system. Dragging wheels. 4WD isn't a rain thing. It's a mud, snow, ice thing.

 

yeah, quit using 4H on hard pavement and read your Owner's Manual:








Note:




Do not use 4H or 4L mode on dry,
hard surfaced roads. Doing so can produce


excessive noise, increase tire wear and may


damage drive components. 4H or 4L mode


is only intended for consistently slippery or


loose surfaces. Use of 4L mode on these


surfaces may produce some noise (such as


occasional clunks), but will not damage


drive components.

 

How much sleet were you getting? The roads would have needed to be pretty greasy before you use 4WD. You should not be using 4 wheel drive on just wet pavement. If there was sleet, you would need a lot of it on the surface of the road to allow the wheels to slip. Wet pavement alone is not a loose enough surface to allow the wheels to slip (such as dirt or snow/ice). Did I understand you correctly? you were using 4WDH on a 200 mile trip? Hopefully, you didn't incur damage but you may have. Were you also traveling at highway speeds on that trip?

 

Yea, no bueno. You could have gotten by with 4 auto. 4 high basically locks the front and rear differentials together. As you turn the front tires will travel a greater distance. If the tires can't slip to alleviate the tension, it is transferred to drive train components. Drive shafts, gears, u-joints, suspension components to name a few. It was hard to turn because without slippage the tires all want to travel at the same speed thus driving straight. Definitely not good to drive around on wet roads in 4 high. Even PARTIALLY ice covered or snow covered roads. It's actually more dangerous as you can get into a situation where the tires could be slipping, then as you steer to keep the course you desire, the tires could regain traction. If it were the front tires slipping you now have them turned when they hit the pavement and regain traction throwing you in that direction. Worst case scenario, but it illustrates the point. Ok, it might be a stretch to say it's more dangerous, but it's definitely not good on the truck. As speed increases, so does dynamic friction and the amount of force required to induce slippage (or in other words the amount of force being applied to your u-joints if the tires don't slip).

The best option is to SLOW DOWN on wet or otherwise slightly reduced traction situations.

A good general guideline to use is if you see CARS driving in it, you probably don't need 4x4.

 

The pavement was soaking wet, not dry.

 

I don't think I have "4 auto."

 

I think the bottom line is you don't use 4wd in the rain.

 

Pavement soaking wet your tires take care of that. Your tires are made to shed the water so you do not hydroplane.

Snow ice covered roads 4WD and slow down. Mud offroading in sand or gravel 4WD.