How often do you put your truck into 4 wheel drive?

4 High, almost daily. 4 Low, not yet. But I’ve only had it a few weeks.
Our driveway is on the edge of a forest. 600 feet long and half of it is at a 13.5 deg angle. With leaves and “tree debris”, the truck wheels often spin in 2 wd, so I use the 4 hi to climb out.

 

I understand the need to exercise the 4WD system, but I am confused by the advice that driving straight on surfaces with traction (dry pavement) will not damage the system. I always understood the function of the differentials to be providing power delivery to the wheels and freely allowing different rates of rotation between the left and right tires. There is a rear differential and a front differential in our 4WD trucks. If this is the case then the damage to the transfer case would be due to different rates of rotation between the front and rear tires (not left and right due to turning). Since the tires are never EXACTLY the same diameter, I would think that there would be a small difference in the rate of rotation between the front and back tires. The transfer case would be forced to make a front or rear wheel slip in order to make them match which would put great strain on the transfer case when driving straight on a high friction surface. I have always avoided activating 4WD on dry pavement due to this concern. Can anyone enlighten me on my misunderstanding?

 

It will bind much more on a turn, you can feel it if you try. That said, I would never engage 4WD on dry pavement, I don't care how straight I'm driving. It's simply not necessary.

 

this has also confused me. not like the trucks have front lockers, right? I just follow the advice about dry roads, but don't quite grasp the mechanical aspects of it.

 

@Jota21 I suppose turning could create a larger difference between the rotation rate of the front driveshaft vs. the rear drive shaft? I don’t regularly drive on slippery roads but purchased a 4WD thinking that it could be invaluable for that 1% use case. Given that the 4WD system needs to be exercised regularly in order to work when needed, I am beginning to regret not getting a 2WD truck. I could have saved some money and increased the dismal payload rating.

 

the concern is that, on a turn, the outside front tire has to rotate faster than than the inside tire, but in 4wd, that creates a binding effect. I guess i'm just confused about what a locker does vs. what we have if ours are 'locked' into the same speed in 4wd

 

Just my opinion but too many people buy a 4x4 and don't use it. I have had several 2wd Fords with limited slip and never stuck any of them. I towed a 3500 lb bass boat and never had a problem on a ramp. When I bought my 93 F150 I took it straight to the tire shop and put some MTs on the rear. I own a 4x4 now to get around the places I hunt and I now have a much bigger boat.

Back to the original subject. I do engage 4wd on straight stretches of pavement when I have not been off road in a while. I try to do it when the roads are wet. I have grass in front of where I store my boat. It was a little damp one day so I engaged 4wd to not leave ruts. I forgot to disengage when I got on my driveway. Normally I notice that I am in 4wd when I turn out of my driveway. I am quessing that I didn't because of the 5000 lbs behind me. I drove 80 miles to the lake before I noticed the light. That was years ago and no problems. Again the load probably helped.

 

Forgot to mention I tried the “ol school” method where you go from 4hi wheel drive back to 2 wheel drive by putting it in 2 WD and then shift into reverse and backup 10-15 feet.

That’s how it use to be done and you’d hear a “clunk” sound and you’d be all set.

But when I tried it there was no clunk and the 4hi icon started flashing rapidly. So I guess it’s a huge improvement over the old days. Just switch from one to the other on the fly.

Although I still switch when I’m at a full stop. Guess I’m still trying to hold on to a little bit of that ol school method

 

The problem is there is no center differential to make up the difference between the front tire and drive shaft rotation and the rear tire and driveshaft rotation when turning. When driving straight, the difference is negligible. The tires can squirm a little as needed during forward rotation to stay in sync if you will. On turns, the tires are not able to slip enough quick enough to keep from binding on dry pavement. I've driven the same 4 mile stretch of straight road in 4wd numerous times in the summer to use the system when there's no snow and mud to find and never even noticed the difference. You can engage and disengage 4HI at speeds up to about 55mph seamlessly.

 

Once a month for me. I was in 4WD almost all last week with the snow we got.

 

So on these Tundras, is there a disconnect at the front wheel hubs? Or are those permanently connected? Is there a differential disconnect or some kind? I haven't even had my truck on a lift yet to see how everything works under there.

 

Front axles are always rotating. Front diff is what “engages” when you select 4hi or 4lo along with the transfer case.

 

I cycle the 4wd only when it's raining. It's an easy way to remember too. Never when the pavement is dry

 

I try to use 4-Hi at least once a month. Always on wet or gravel roads though, never on dry pavement. Even in a straight line on dry pavement you can get wind-up which can destroy your transmission.

Here's a really good video on the subject. https://www.youtube.com/watch?v=1EHcrjIlkHk. At 4:44 of the video it has a great visual showing wind-up.

I use 4-lo about once a month when I pull my camper out, mainly to keep everything lubricated and not tear up my grass that I have to drive through to get the camper out.

 

sooooo, specifically says you have to turn to create windup. No mention of damage while driving in a straight line while in 4wd.

 

The only time I had to do the reverse thing was when I had trucks with manual locking hubs. I had a buddy that forgot to disengage 4wd after getting on pavement in his 70s model F150. He pulled over and we could not disengage the hubs. At the time we did not know to back up.

 

Go to 9:35 of the video and watch it from there. And I've never seen a 100% straight road. Just small swerves from side to side in your lane can cause windup.

I don't really care what people do though. It's not my truck.

 

Ah ok. Thanks. So is the actuator on these electric, vacuum, or gas operated?

I had a '88 Chevy truck that used a gas-charge operated front differential actuator, and in cold weather it wouldn't work well. They eventually upgraded those to electric operation.

Fords use vacuum systems, and those also suck.

 

Electric

 

@normagene

the system is designed for slip to operate the smoothest.
better to use it in the dry every now and then as mentioned, no big turns, than not at all and have the actuator need replacing.
if you are running All Season Tires in winter - they get pretty hard once you hit single digits in celcius or about 40 F.
they will slip for you.

 

Fords suck period

 

Everyone has already covered the 10 miles/month, but make sure if you’re on concrete you’re only going in a straight line, don’t try to turn while it’s engaged

secondly, I would suggest once a month shifting into 4low as I’ve found if you don’t do it regularly the truck doesn’t like to shift (you don’t have to drive far, just shift move a couple feet, then shift)

if you go to shift into 4low and the light just flashes and beeps, leave the truck in neutral and the switch on 4low and turn off the truck then turn it back on, it’ll get the computer to throw the truck in 4low

 

Never thought about this. I need to start. I just have to find a nice gravel road near me.

 

Maybe rotating the tires every 5,000 helps to keep all four tires close to having the same circumference. Me, try to do this exercise when raining if no low traction roads are available.

 

Unless you are doing burnouts the difference is not worth worrying about. I do rotate every 5 to 10k.

 

Same with me. Driveway is 250' long base rock not to steep, 7° maybe, but in four wheel drive it helps minimize damage to the surface.

 

Only as I need it which is usually a couple times a month. During the monsoons, both high and low get used daily.

 

I live in north GA so not a lot of snow to exercise 4wd, but I do use 4wd high in heavy rain on the interstate. It makes a huge difference if you hit water. With the front wheels driven and pulling, it tracks straight and won’t pull to the side. The radius of interstate turns won’t create any issues with binding. The wet pavement also helps.

 

I used mine for the 1st time today with less than 900 miles on the clock...pulling off an unplowed ice/snow drifted turnoff. I always used the 4wd like a shift on the fly in the Chevy...but was cognizant of constant speed when shifting into or out of while on the roll. I never even thought about the 4wd in my Chevys. They just worked like an old anvil, and never let me down. All this chatted about constantly using the Yota's 4wd, or else...makes it seem fragile in comparison. I actually kinda cringed when putting it back into 2wd while on the roll.