When is it exactly right to engage 4WD?

[izzywolf]

Hi, I'm new to overlanding, and off-roading.

I've read that you should never engage 4WD unless you're in a low traction situation, otherwise you'll mess up a lot of things.

So is there an exact minimum on how, for example, wet the road has to be?

 

[genocache]

Hmmmm, With 4x4 too much traction can be an issue. What vehicle and type of 4x4 system have you got?

I've known peoples who drive around in 2 wheel drive until they get stuck, then put it in 4x4 and get unstuck, they call that fourwheeling, then others who put it in 4x4 at the first sign of lack of traction or steep uphill to spread the load around and off the rear wheel drivetrain, and call that fourwheeling.

Unless you have one of the new fancy ABS driven traction systems you want to avoid driving on dry while in 4x4.

 

[Urban2Overland]

I have a Gen2 Shogun at terrains tyres rear and central lock 4h 4L system.

But I'm a novice and will pic up the pace.

 

[Urban2Overland]

4x4 high for slippery roads.

4x4 low if complete off road.

I have a 99 shogun/pajero/montero depending on what side of the world you are from.

These have rear and central locking but I can only engage lock system in Low range 4x4

 

[Trail_pilot]

Typically 4hi for anything off pavement is OK, and 4lo if you need the lower range from the t-case for obstacles.
Typically on a trail, if it's not a technical section I will pop into 4hi to make up some time to teg to camp, but as soon as I see an obstacle I am back in 4lo. If I am running in a group and we are traveling slowly, I will leave it in 4 low through the whole trail.

 

[Dlnuckolls]

I am in the same camp from the previous poster!

Generally 4-H for off pavement and 4-L when needed. It affords me a slightly better fuel economy that way, and the power when I need it.

 

[MMc]

Read the owner manual for your make and model, Google is your friend for this kind of stuff.

 

[Billiebob]

First, read the Operators Manual.
Second tell us what you are driving.

 

[Billiebob]

I'll take it for granted, you have the typical North Americam 4x4 with a 2 speed transfer case.

Genarally today 4x4s have identical ratios in both axles.
In a straight line, 2WD, 4WD, no difference regardless of the road.

Yes, turning a corner in 4WD will tend to push the 4x4 in a straight line.
So turning a switchback on a 4WD only mountain road, you might want 2WD for control.
And in the winter at WalMart on an icy snow covered parking lot.... you will NEED 2WD to turn tight enough into the stall between to BMWs .... or maybe not
4WD HIGH. Gearing is the same as 2WD so on the highway, snow, slush, dty, wet pavement..... feel free to use 4WD HIGH full time. I do this every year, No issues.
Like the WalMart parking lot, shift into 2WD before turning off the highway on a sharp corner.

I'll get slagged for that comment, about using 4WD on the highway but watch the rock crawlers on granite, the grippiest rock ever, look at the black rubber they burn off in 4WD...... you in 4WD on the highway will leave zero rubber on the road.

I'd agree, you want 4WD in low traction situations, but NO, 4WD in high traction situations, ie rock crawling or highway driving, 4WD will not screw things up.

4LOW is about speed control, reducing driveline stress, gaining control. Pick it anytime 4HIGH just feels too fast. Or you want better control.
Try 4HIGH, 4LOW see what the difference is..... you can do this experiment anytime, anywhere. Even on a paved parking lot.
Try it, feel the wheel hop turning tight on pavement in 4HI and 4LOW. You will not break anything.
But you will feel the differences. You will learn.

 

[Billiebob]

If you own a 1970s 4x4,,,,, many of them had different ratios is each axle. They are the reason for the scary warnings,
But you would never be in 4WD long, on the highway my F250 would howl in 4WD.
The manual said, back up 15' to relieve the driveline bind and shift into 2WD.
It had 4.10 in the front, 4.11 in the rear.

I dont think anyone does that today but it was common 50 years ago. and what causes the misinformed comments today.

 

[leeloo]

Depends on the car actualy. read the manual specific for you vehicle. Most modern pick ups default they run 2wd, when you engage 4wd, the central diff is locked. In high traction situation ( dry asphalt this can lead to premature wear. ) Your shogun has the same system. As soon as you leave the pavement you can engage 4hi.
More difficult bits you go 4 low, also on big slopes 4 low helps a lot with engine braking, you avoid to overheat you breaks.
For me it seems kind of stupid to wait to get stuck. On loose surfaces even like an easy gravel road you have a lot more control on 4x4 and it does not hurt the drive train either. No reason to keep it in 2wd.

 

[Sneaks]

For me it seems kind of stupid to wait to get stuck.

Agreed. I was always taught that "saving 4wd for a situation is creating a situation that doesn't need to exist".
Older (like decades older) designs would bind the tcase on dry pavement (BTDT in a 77 Trailblazer) with spectacular results, same with modern ones if put in the "lock" position. Read the manual, it will tell you what situations you should NOT engage.

 

[roots66]

First, I want to say it's great that you are asking these questions. I'm glad you are seeking advice from people who have experience rather than just watching a bunch of videos and thinking you now know everything. Thank you for being proactive.
Never on dry pavement. Outside of that, it becomes vehicle and condition specific. There are just too many variables involved to give a one-size-fits-all answer. Like mentioned before, the owners manual is your first source.

 

[Alanymarce]

Short answer - "before you get stuck"/

Long answer - as others note, depends on the vehicle - our LC80 was permanent "true" 4x4. Our Montero is 2WD, 4WD Hi, 4WD Low, and 4WD low with lock. We've owned a variety over the years and have always selected as follows:

- dry tarmac - 2WD (other than on a permanent 4x4 vehicle)
- wet tarmac - 2WD (other than on a permanent 4x4 vehicle) - no problem with good tyres
- very wet tarmac - 2WD in most conditions (at speeds below aquaplaning limit), occasionally 4WD if the surface is really slick
- snow and/or ice on tarmac - 4WD
- unsurfaced road/track - 4WD - always - engage on starting onto the unsurfaced section
- mud, sand, etc - 4WD either high or low range depending on conditions
- deep mud, deep soft sand ascents, very uneven rocky tracks - 4WD low+locked diffs.

Other than with diffs locked we've never encountered a change in turning radius.

 

[izzywolf]

Hi guys. Have my kid for the weekend, so I've been a bit busy (but certainly grateful!).

I completely did not expect so many of these helpful responses. I truly appreciate you all reaching out.


I probably should've stated before, I don't have a rig for overlanding yet.

I'm planning on getting a truck for welding/hauling, and thought I could make it my rig too.

 

[ThundahBeagle]

Todays 4x4 is different than older 4x4, at least for a lot of makers. If I understand correctly it is more of a clutch-pack now, at least in GM trucks, which is what allows the auto-4x4 mode. It is technically weaker but also more versitile.

I have found that engaging 4hi on simple wet pavement alone, and making tight turns, will be enough to introduce a groan or hop due to unwarranted stress on the 4x4 system.

While I do not advocate "getting stuck first", I do advocate staying in 2wd as much as possible. Even offroad, you can get pretty far in 2wd. Ask around or check the 2wd part of this forum if you dont beleive me. Certainly on fire roads and 2-tracks. When you get near loose dirt, or an incline, or water or an obstacle, turn into 4hi. Or 4 lo if it is really bad. I try to be mindful where I am and what lies ahead before I swap to 4x4, but then, I dont rock crawl or sling around in mud. I'm basically a guy who wants to take 2 tracks and fire roads to nicer camp sites.

Anyway...On just wet pavement, I may or may not go into auto-mode. I swap to 4 hi only when I see ahead of me an issue where I could get stuck or could slip, such as ice or snow, or heavy rain, sleet, freezing rain, what have you.

I hope that helps

 

[oldmopars]

I will second the need to read the owners manual. Each vehicle is different and you need to know the type of transfer case you have. Most modern vehicles have an open T-case that allows for driving in 4wd on any surface. Some have a “lock” position, if so you need to limit its use in high traction driving so you don’t cause binding cause when you turn. The front and rear tires travel different distances and this will bind up the T-case if on solid ground.
You really need to understand the type of system your vehicle has and the owners manual is the best place to start. Then Google it. Or post more specific info on your rig.
We can help, but need all the specific info on your vehicle.

 

[izzywolf]

4x4 high for slippery roads.

4x4 low if complete off road.

I have a 99 shogun/pajero/montero depending on what side of the world you are from.

These have rear and central locking but I can only engage lock system in Low range 4x4

I totally relate to saying "shogun/pajero/montero", translating to my European friends what we have in the U.S. Where I lived it was called the Pajero.

 

[Alanymarce]

I totally relate to saying "shogun/pajero/montero", translating to my European friends what we have in the U.S. Where I lived it was called the Pajero.

I do the same - had a Pajero in Africa, and have a Montero now (in Colombia).

 

[BensonSTW]

I run 2wd 90% of my offroad travels. 4 hi is for when the tires start to spin. I hate the thought of chunking out 2 grand in tires. I will also use it anytime there is snow. Power to wait ratio will cause most trucks to sit and spin in the snow. 4 low is for when the engine starts to bog down, if I need to go slower than 4 high due to rough terrain, or when 1st or 2nd gear doesn’t want to hold me back on a down hill. I absolutely hate when people ride the brakes going down hill. When you overheat your brakes and start to experience brake fade, it can cause some sketchy scenarios on the trail. It’s actually kind of interesting to see when others will decide to lock in the t-case and why. I know a guy that uses 4hi anytime he leaves the pavement.