I am coming from vehicles that were either all time 4WD or 2WD so forgive me if this is s stupid question.

The manual is clear that the 4X4 system is to be used off road or ice/snow conditions and not to be used on dry pavement. What about heavy rain? I am going on a trip this Saturday and it is about 90 miles each way and the predictions are for heavy rain. Is this appropriate for the 4X4 system and will I do harm if I drive freeway speeds for that long of a distance?

Thanks

 

Unless its severe flooding with rushing water, i would see no need to engage 4x4. Ive driven though many serious storms, high water, even a tornado and not once have i needed to use 4x4. I am not in any way advising you to do as i have, just sharing my thoughts and experiences.

 

The bottom line is to use 4X4 only on slippery surfaces. Rain does not always indicate the road is slippery and in some cases increases traction. I know that sounds crazy but the physics are there. Keep in mind that you're not going to automatically break the truck if you drive in 4X4 on high traction surfaces. It just increases binding and pressure on all components of the driveline if the wheels are driving at different speeds when locked. The truck will complain and all you have to do is switch back to two wheel drive.

 

I would recommend not using 4WD in wet roads like other said, doesn't mean the roads are slick.

On slick roads, if needed I will use it, but as soon as I get going, I switch back to 2WD

 

If you have to cross flooded roads deeper than the tires, and the water is moving, I would maybe use it.
I've had my SD's in water up to the door bottoms a few times in 2wd with no troubles though.

 

turn around, don't drown.

 

If you're driving in rain that is coming down so hard you need 4x4, let off the gas, you're going to fast.

 

4wd needed


4wd not needed

 

My old man always said to use 4 wheel drive any time I drive on dirt roads even if you don't need it. His logic was to keep everything lubed and moving and stretch its legs every chance I get.

Only use 4x4 on pavement in the snow.

 

I tend to agree.

 

Yup, 4x4 only necessary in low-traction situations. Rain is not normally a low- traction situation, unless you start hydroplaning, in which case you won't have time to switch and it wouldn't do you any good anyway.

It's definitely a good idea to run around in 4x4 on some unpaved roads every now and then, it keeps the grease and oil moving around and keeps everything lubricated. O rings and seals go bad because they dry out.

 

To the Original Poster:

4x4 is almost never needed in the rain. Think about it: there are far more vehicles on the road with only two wheel drive than there are vehicles with 4x4 or AWD. How often do you read about 2WD vehicles going off the road or crashing because it was raining hard?

Ricohman's example isn't necessarily because of the water, but rather because of the rocky / muddy bottom beneath the water.

Part-time 4x4 vehicles should limit 4x4 use to off-road and snow/ice.

 

If you're worried about the rear end sliding around on you, you can put a few hundred pounds of weight in the bed over the rear axle, but don't lock it in 4wd on the highway in those conditions, you could actually lose control when the front end binds up in a curve if it grabs.
4wd behaves much differently than AWD.
​​​​​​​But with new tires on the truck, I don't see a need to worry unless you plan on driving 90mph in heavy rain.

 

Remember that your new truck has stability control, which mitigates one of the big reasons for 4WD. If you break traction the truck isn't going to go sideways; sensors will detect the loss of traction and reduce power. If the truck enters a skid the system will apply brakes to the wheels on the outside of the skid to bring the truck in line. You'd have to do something quite reckless to put your truck into a spin.

You should try it out sometime in a snowy parking lot if you have them in your area. Playing around in low speeds I've been unable to get my truck to spin. Within a split second of the truck starting to slide the brakes come on and the truck is drug back in line.

 

Why do only three of four wheels engage into 4wd?

Drivers side front does not