4x4 HI/Low - What is OK and what isn't?

You shouldn't really need to lock the wheel in 4x4, but it depends on how well the tires can slip. My F-150 would literally hop when binding. I can't really name a situation where you would (a) need 4x4, (b) need to turn sharply, and (c) be on dry terrain.

To be fair, the transfer case can take some serious abuse before dying. Fun story, my Jeep Wrangler had a TSB to replace the plastic retainer clip that allowed you to shift out of 4-Low. I found out when mine broke and drove it on dry-pavement for about 15 miles to the dealer at around 45mph. Nothing broke. Took lots of turns. It's definitely not good for it, but it's interesting how much abuse they can take. I doubt you've damaged anything.

https://www.youtube.com/watch?v=yYAw79386WI

 

Haha that’s funny!!! I didn’t even catch that I did that. My wife’s even an English teacher and she’d definitely shame me for that one. It’s now corrected.

 

When you turn in 4HI, the front driveshaft needs to be driven faster than the rear driveshaft. It is my understanding that this is what causes the binding on dry pavement (i.e. since your transfer case is now locked).

The outside wheel needs to turn faster than the inside wheel, but since you're in 4HI, it's open diffs all around (except your transfer case, which is locked in 4HI), thus there is no binding between the inside and outside wheels (that's exactly what open diff is for). If you lock your rear locker (in 4LO or with 4HI mod), then you will experience binding in the rear axle as well.

In any car, in a sharp turn, the inside rear tire turns the slowest while the outside front tire turns the fastest.

 

Great summary. Thanks!!!

 

You need to stop.

Close, but in 4HI with a direct drive ("locked") transfer case the binding occurs anywhere and everywhere throughout the entire drivetrain system and the open differential does not alleviate this bind across an axle. The reason is there is still a fixed relationship with an open diff as it pertains to the speed of the outside wheel, the inside wheel, and the input (driveshaft). When only one axle is driven the inside wheel spins the speed it wants, the outside spins the speed it wants, and the driveshaft adjusts to the total speed of both wheels. With the transfer case in 4HI the driveshaft cannot adjust freely to the ideal speeds of the inside and outside tires (because it also now has a fixed relationship to the other driveshaft which may desire a different speed) thus creating fighting across the differential for their share of the input speed to achieve their ideal individual speeds.

 

I live in the rocky mountains so lots of off road adventuring and snow driving.

Four wheel drive is like abs and traction control. You want to drive in such a way as you don't need it. So in snow,.if there is visible pavement, keep it off. The front wheels turn faster than the rear wheels so driving in 4x4 on pavement is brutal on your driveline.

If the road is snow covered then turn on 4hi. But depending on conditions you may be switching in and out of 4hi a lot as road conditions vary.

Off roading. Go as far as you can in 2hi. When you get stuck or can't go any further, turn on 4hi to get unstuck. But you really don't need 4hi for dirt roads or most off roading. If you need 4x4 you should be using it to get home, not to keep going.

4lo. To get out of snow packed parking spots or, the only time I use it, for descending steep grades.

Yes,.it is really good to go into 4x4 occasionally to keep things working,

But for those of us who live where you need 4x4: 4WD isnt to get you there, it's to get you home.

 

I go under 55mph to switch into 4H, but you can drive any speed in 4wd, but not engage it at any speed. Snowy/Icy roads with turns, even when patchy, I will leave 4wd on. The roads have mostly gentle turns here and I feel were almost designed for 4x4s. There is one sharp turn I take getting to work and if its mostly dry, I will turn 4H off to make it and then re-engage it.
4LO for off road and having more control and traction, easier in a MT too for me. Also good for deep snow! Usually going 20 or less sometimes a bit more, usually less though.

 

Just as a counter viewpoint I've never ever understood this thought process. The instant I'm "offroading" I'm in 4wd and most likely 4LO. I'm not interested in struggling in 2wd, spinning tires, slipping clutch, and banging on my drivetrain. I have no plans to "get stuck in 2wd" and then try and get out. Just 4LO, rear locker, and toggle front locker at obstacles and difficult sections. I'll wait to hammer on the truck when I find something worthy of hammering on.

 

Not to mention the safety of being in 4wd at higher speeds on a dirt road...

 

I thought the same thing and I agree with you. As soon as I’m onto dirt and have hills to go up or down I’m in 4LO. It’s so much easier on the drivetrain, tires and transmission temperature.

If I have to turn around I throw it back into 2HI and do a 3-point turn, or if I need 4WD to turn around I make a 10 point turn so I don’t bind.

There’s a ton of beat up 25 year old 4WD Toyota’s around here with 16 year old kids hammering on them and they don’t break. They are way tougher than some people give them credit for.

 

Maybe the kind of off roading is a factor. I did the entire White Rim Trail in 2WD because 4WD just wasnt needed. No tire spinning, clutch slipping, etc.

But I get your point,.if it was more rugged,.etc,.4WD would give you a lot more control. But I've also seen oh,.oh so many people buried and totally stuck because they thought 4WD would get them through. If you know what you are doing, you can get in really deep, and crawl through a lot of obstacles in 2WD.

So the joke around here is "4WD just means you gotta walk further to get back out"

 

shit i slap it into 4hi almost everytime i hit dirt/gravel. I drive pretty fast on those roads and my wheels must be slipping when I turn. If i was in 2wd i’d be breaking traction and fish tailing slightly. I wonder if I’m doing any damage...

 

No

 

This is the correct answer
These trucks are not race trucks slow and steady wins the race

 

4hi is fine for off-roading and slight turns on dirt/semi-loose surfaces. But if you plan on making some tight turns on “dirt” or something other than ice or mud, you should really just switch to 2wd.

 

As stated before, you will feel it when your truck doesn’t like it. Another thing to remember is to turn traction control completely off. It will likely get you in more trouble than it’s intended purpose.

 

Hey Jbrandt...you mention Mauna Kea mountain road...The road to the telescopes...unimproved road starts at 9,000 foot level and goes all the up to 13,000 foot level...Best to be in 4-low ,up and down.. It is beautiful up there..We go only when it snows...!
There are many steep hills in Kona , Hawai’i.. , but when you stop on a wet and rainy ..road...many times with bed so light, going up hill from a stop .the rear tires will spin out...then I shaft into 4-Hi..till I get moving..mainly at stop signs or someone’s steep driveway..

Hope you had a great time on top of Mauna Kea mountain...one of the tallest mountains in the world..from below sea level.. Many people would fill trucks with snow and built a snowman at the beaches..or at home..
Aloha
When you reach the top...that is a real 4-wheel high! ..it did snow this week, today is Jan 20,2021...

 

Switch it into 4Hi every so often so you keep all the mechanisms free and lubricated and so you are alerted to anything not working before you need it.

Gently curves are fine in 4Hi whenever.

4Lo when you are climbing steep off-road ascents to save your tranny temps. 4Lo descending to save your brakes. 4Lo on a forest service road is painfully slow so I would stick to 4Hi in those situations.

 

I'm from northern Maine, grew up driving in the snow in awd and 4x4's and fwd. I can honestly say I've never heard "front wheels turn faster than the rear wheels" before. Unless you're running some different sized tires front and rear, they should be turning the same speed. In a turn, sure they turn at slightly different speeds relative to the inside and outside tire, but it's such a minor difference in a slight turn on a road, it won't bother the driveline at all.

I also can't agree with "if there's visible pavement, keep it off." The road conditions change extremely quickly in winter in many places. Just because you can see pavement, doesn't mean it will provide good traction or that it doesn't have black ice on it. Around the next turn the road could be completely white because of the wind. My family put 200k miles on our 06 tundra, and it spent most of every winter in 4wd at 50-60 mph day in and day out without any failure. Honestly the only times it was in 2wd in the winter was when I was driving it just so I could have fun.

My point to op is this: if you feel like you need extra traction/confidence in questionable traction conditions. Use 4hi. If you need to go slow and take your time, use 4lo. Yes avoid going to full steering lock when in 4wd. If you need to make low speed tight turns, (15mph and under) use 2wd if possible. If doing so will result in you getting stuck, the truck will survive being in 4wd for the rare occasion it happens.

 

As a rule, you're only allowed in 4X4 when its slippery when wet



Edit: But some guys just don't care