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

Hey, I'm a newer truck owner.

I just wanted to know, what is ok to do when in 4x4 Hi/Low?

I've read a lot of things on this site already but just wanted to ask and have my own answers. I've driven on snow and ice and sand before with 4x4. I recently used read that I'm not allowed to turn a lot using 4x4 Hi? Is this true?

I appreciate the help and answers!

 

When you’re turning, your wheels need to travel at different speeds from each other (inner wheel needs to travel less distance than outer wheel); but if your in 4wd, they’re not able to do so. So if your turning while in 4wd, and the wheels are not able to slip, this could cause the driveline to bind.

So typically, you’d only want to ever use 4wd in slippery conditions or at least on dirt. Many people will occasionally temporarily use 4wd on pavement in a straight line, just to keep things freed up and moving.

For 4hi vs 4lo... 4lo would be low speed crawling; where you need high torque, but low wheel spin. This would usually be when your are really stuck, or need to crawl up an obstacle (more so off road scenarios). For 4lo you would be like 25mph or less.

4hi would be more so for typical driving in slippery conditions; or general off-roading where you can’t quite make it in 2wd. Higher speed driving and more wheel speed/wheel spin.

 

For those of you who live in winter climates (i don't), on the highway, you don't use 4HI? IF you do, and there are turns on the highway (curves), is that ok while your 4H is on?

 

All of the above is correct. However I’ll add that you can use 4h on the highway even if it isn’t necessarily slippery. Gentle turns / curves are ok but you really do not want to turn into a parking spot on dry pavement. I had never shifted mine into 4h at higher speeds but the manual says you can.
It is good to exercise the 4x system about every 1-2 months and if you have a nice straight stretch of road it’s ok to do so even if it’s dry. Just NO sharp turns

 

Only used if really needed; if there’s snow or ice on the road. In which case, turns/curves are fine, because the wheels are able to slip if needed.

 

If it's bad enough I'm using 4hi on a snowy freeway, I'm still not going any faster than 45mph, and that's if everything is wide open. I think the book says 55 max.

It's fine to run at moderate speed in 4hi and make turns if there's snow under the vehicle to allow the wheels not to bind.

 

I live in Texas now but from where I'm from, most only use 4x4 when there's ice (e.g. snow melted during the day and froze again at night). Usually, it's not needed for light snow. Interstates are usually thawed out by salt and other cars but during snowstorms, it can ice over fast.

 

https://youtu.be/M9MjFyU1S2g

 

Gradual turns at speed won't hurt anything. Its the slow moving sharp turns like in parking lots that really bind it up.

 

Parking lot speeds and super sharp corners where you have a ton of traction is when it really becomes and issue. Driving our truck home after Christmas we did probably 70 miles on compact snow and ice in 4Hi with no drama.

 

To add: You can usually feel the truck binding up when there's too much traction via the steering resistance. The truck will fight you at turning/moving forward.

 

Ah I see. I understand now. Thank you

 

Not "allowed" to? Well, the 4x4 police aren't going to come after you if you do, lol, but it's more about minimizing wear and tear on the drivetrain.

A lot of people are scared to use 4x4 on the road, and say you should never do it. I think those people are being a little dramatic. If your truck can't handle a little driving on pavement in 4x4, there's no way it could handle the rigors of off road driving. That doesn't mean you should do it all the time, but it won't make your truck explode.

As I said, though, it's about wear and tear. So don't do it often. I drive around in 4x4 in the rain all the time because in the wet, our pickup trucks have especially little traction (weight over the drive wheels).

As for 4hi vs 4lo: Lo range is simply a set of lower gears, so if you're driving in 4hi, and you find that you need lower gears because you can't go slow enough without lugging the engine (or excessively slipping the clutch or riding the brakes in an auto), that's time for 4lo. This is commonly when driving extremely slowly over very rough terrain/rock crawling. 4lo is also often used to help control your speed on steep descents, technical or not. Even on asphalt, 4lo can be very advantageous. Like coming down from Maunakea in Hawaii (telescope observatory at 14,000 feet). It's a paved road but it's steep and long and without low range you'd smoke your brakes and probably die, or at a minimum forfeit your damage deposit on your rental car, lol.

There are a lot of different opinions on when you should use 4lo vs 4hi for various conditions. Sand, snow, etc... I'm of the mindset that there is no one rule that applies everywhere. That's more of a function of driver experience and preference. So get out there and drive, and don't be afraid to experiment.

 

I’ll also add you can shift into and out of 4hi while moving. When I go snowboarding the road almost always is iced over. When I turn onto it I’ll slow down to about 10mph and shift into 4hi.

 

I've has this situation before and I'll ask TW: if you're in 4lo (MT) and need to keep momentum so you need to get to 4hi, can you switch on the fly? 4hi to 4lo I know you have to stop, but I haven't heard much chatter doing the other way around. Thanks.

 

I’ve used it to get out out of parking spots before and stuff and I did notice that it was much harder to turn when getting to full lock.

will it damage my 4x4? I’ve only done like less than 5 times. Never felt anything or hear anything weird happen during those time.

 

I’ve felt this before and wondered what that was. I never fought hard against it, but rather just turned the wheel as far as it would let me and got out of the lot or where I was. I’ve only done (and used 4x4) this a handful of times during my whole time owning the taco.

will binding it or having it reach steer lock damage anything?

 

The damage is cumulative. You'll most likely not have the transfer case explode, but the more time spent in 4X4 in good traction situations the more damage you do and the sooner parts will fail. Even off road, if traction is good, shift out of 4X4 until you need it. Parts breaking is pretty common for guys who push their rigs hard off road.

Here is what you're doing. There is a drive chain inside of the transfer case to transfer power to the front drive shaft. Every time you place the drive train under stress the chain stretches. Over time it will stretch to the point where it starts slipping on the gears when you accelerate from a stop. The only cure is an expensive transfer case rebuild. BTDT twice. Don't drive in 4X4 on a surface with good traction. The wheels need to be able to slip and spin slightly.

 

Slight curves on the highway are ok.

 

Yes you can do damage that way. If you bind up and keep forcing it you can break a CV axle, or worse. If anything breaks though it would most likely be the CV axle.