When to use 4 low? (1 Viewer)

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MCtree

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I’m on vacation and have been doing some dirt-road driving in the Telluride area and I realize I don’t know when to switch to 4-Low.
When driving on steep forest roads, I don’t have trouble in 4-high. But I worry I’m unnecessarily taxing my engine.

This thread from the 100’s seems to imply that I should switch to 4-low for most dirt roads (or off-road) under 20mph. (As do the two Ronny Dahl videos embedded within)


Do you guys agree?
Or is there any reason not to put it into 4-low for our 200’s?

I’m curious if any of you have watched your transmission temps and noticed a difference between the temps at 4-low vs high.

For my next trip I will have a Bluetooth ODB reader like linuxgod suggests here so I can see what my temps do.


But it didn’t occur to me for this trip….
 
First thing I do when I hit the dirt is air down. The second is shift to 4lo.

Unless you are traveling over 30mph and/or on flat ground, no penalty to shift to low. You get much better engine braking, and it’s a lot less stress on your drivetrain.

I wouldn’t worry about babying the truck.
 
You’re going to get a lot of great input from far more experienced drivers than me, but it kind of depends on the terrain. On rolling fire road / trail i find myself staying in 4hi. As the terrain gets steeper and or the obstacles increase, then I tend to switch to 4 lo. But again, it depends….lots of variables that can influence your choice.
Oh, and what @tbisaacs said about airing down…first things first.
 
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I do most of my dirt travel in the Southeast and for the roads I’m usually on I don’t air down but will run 4L to stay off the brakes. When I’m towing on these roads I’ll run 4L the whole time, it keeps the trans temps down and I’m not traveling more than 30.

This brings up a question for me, is there a max speed for 4Low?
 
I know on my LX, it won't go into higher than 4th gear while in 4lo. It's not very fast.
 
Done lots of trails around Telluride, Ouray, Lake City. Generally speaking, I've only needed 4 low when going down a trail to avoid too much brake activity. If most of your driving is on 1st world roads, when you're on a trail it's good to shift in 4 low just to move the gears around a bit. Otherwise they will feel ignored and not valued in your relationship with them. Then they'll see a therapist to work out their abandonment issues with you. Just use the 4 low every now and then to avoid all of that.
 
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I think the best advice would be: If something makes you nervous, go into 4lo.

You will learn when to go into low range with experience.

I usually do this:

Sand, mud or snow: high and momentum is your friend.

Unless you get stuck, you will need to go into to low to use crawl control to aid in getting unstuck.

Rocky or really steep (up or down): low and use crawl control if you are super nervous.

Crawl control will get you up and down some crazy stuff.

After all that you will want lockers and get yourself into all sorts of idiotic situations.
 
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You will rarely need 4L in these rigs, outside of true crawling or the like. I've made it up alpine boulder fields (steep mining roads covered in rock and shale) in 4H, only because I didn't think to shift.

Personally, I think it's good descending from time to time as mentioned and I like to use it sporadically just to keep everything moving.

But the truth is, you'll likely rarely actually need it.
 
Bfgoodrich has a good guide, read through it.

 

Attachments

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I'm in 4lo more often than not off-road. Unless overlanding on featureless and fast open fire roads that I can do over 30mph on, I'm in 4lo.

It's less stress and heat on the drivetrain, especially the transmission and torque converter. More cooling from circulating fluids and engine run fan. The strait cut gears (where the gear whine comes from and something I've come to enjoy) in the transfer case are stronger. Throttle response is more precise and easily modulated, with less wear on brakes.

For LXs, the suspension sets itself up for more clearance and compliance, and increased speeds in high. With breakpoints at 25mph and 50 mph all holding relatively higher positions.

I would recommend using more of 4Lo. I see many that don't use it enough, leaning on the torque converter and transmission and getting things hotter than necessary. Possibly a partial contributor to boiling fuel.

It's a great tool at your disposal. Something to learn and practice with.
 
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Hard to say it, but you'll need to develop your own sense of when to make the judgment call. The 200 is insanely capable in 4 hi, and depending on how, where and when you drive, you may never need 4 low.

4 low can be your friend though. I find it most useful in situations where lower gearing makes sense, like, for example, when doing slower technical off-road trails (as contrasted with just being on dirt roads, forest service roads and wide open non-technical fire roads).

Although said tongue and cheek above, it really is good to engage 4 low (and the center diff lock) periodically to make sure the actuators get exercised and you know they will work, if and when, you need them. It is not uncommon for vehicles that have never or rarely had these features engaged to have issues with the actuators not engaging. The typical family hauler 200 has very little reason to be in 4 low, so a lot of the off-road oriented features never get used by their first owners.

Sitting on a trail with the little indicator lights flashing and the 4 low and/or center diff lock not working is not a feeling you want to have.
 
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I 4x4 all over Arizona and Moab with my T100. After move to Texas I bought LC and have not had much opportunity to 4x4 in this state. With my T100 I only ever engage 4lo it I could not climb something in 2high or 4high. I used 4lo more for descending as engine braking control for decent was far greater and I needed a lot less brakes. For the tiny bit of off road I did here in TX I was in normal mode. I did take my LC to place called Marble Falls and I had to use 4lo their for both climbing and decent.
 
I use 4lo based on how I see the transmission heating up.

I’ve used it while ascending and descending Pikes Peak and while maneuvering a loaded 6x12 haul trailer in reverse through deep snow in an alley in Chicago.
 
I use 4Lo more for control and modulation rather than thinking of it was a traction device. Braking - yes. Temps - yes. Throttle is more forgiving.
 
I think the best advice would be: If something makes you nervous, go into 4lo.

You will learn when to go into low range with experience.

I usually do this:

Sand, mud or snow: high and momentum is your friend.

Unless you get stuck, you will need to go into to low to use crawl control to aid in getting unstuck.

Rocky or really steep (up or down): low and use crawl control if you are super nervous.

Crawl control will get you up and down some crazy stuff.

After all that you will want lockers and get yourself into all sorts of idiotic situations.
But on the other hand if you are sane you may not want additional aids to get you further into trouble. Believe me it is far more amusing and cheaper, to watch others do what they probably shouldn't. Owning a Land Cruiser doesn't make one immune to "Hold my beer and watch this".
 
All,
Thank you for your input! I put it to use today on Last Dollar road (I don’t think you even really need 4x4 for this road, but it’s a good starter road for nubes like me). I immediately put it into 4-low when I hit the dirt.

Nobody came up with a reason not to put it into 4-low, so I figure I might as well do it.

Though when I get an OBD reader I’ll do some testing on how 4-low affects transmission temps.

It certainly helps slow the vehicle down when descending.
And it also helps keep me below 20mph on roads where it would be stupid to go faster (but I get stupid occasionally).

But a couple of follow up questions:

@tbisaacs: would you air down for a very simple dirt road like that? I didn’t because I know it’s only a two hour drive or so and was lazy.

All: how about the center dif locker? I didn’t lock mine. When would you do that?

All: when going up an incline, do you keep it in manual and pick the gear or do you leave it in 4-low auto?

Tomorrow: Ophir pass.
(Happily Black bear and Imogene are still closed. So I don’t have to come up with excuses on why I didn’t do those.)
 
All,
Thank you for your input! I put it to use today on Last Dollar road (I don’t think you even really need 4x4 for this road, but it’s a good starter road for nubes like me). I immediately put it into 4-low when I hit the dirt.

Nobody came up with a reason not to put it into 4-low, so I figure I might as well do it.

Though when I get an OBD reader I’ll do some testing on how 4-low affects transmission temps.

It certainly helps slow the vehicle down when descending.
And it also helps keep me below 20mph on roads where it would be stupid to go faster (but I get stupid occasionally).

But a couple of follow up questions:

@tbisaacs: would you air down for a very simple dirt road like that? I didn’t because I know it’s only a two hour drive or so and was lazy.

All: how about the center dif locker? I didn’t lock mine. When would you do that?

All: when going up an incline, do you keep it in manual and pick the gear or do you leave it in 4-low auto?

Tomorrow: Ophir pass.
(Happily Black bear and Imogene are still closed. So I don’t have to come up with excuses on why I didn’t do those.)
You’ll find the OBD reader extremely informative, at least I do. Long slow climbs in 4H will increase your torque converter temps, in 4L not nearly as much. A lot of this depends on several factors like your vehicle weight, tire size, and if you’re towing.

For me, airing down isn’t necessary for quick jaunts on regular forest service roads, or even long drives on regular good gravel forest service roads, you’re likely to see someone in a camera or Prius on those. Ruts, mud, sharp jagged rocks, big steep rocks things that you wouldn’t see a Camry or Prius on is air down potential.

Shift as needed. I find myself shifting on down hills to engine brake or on up hills to keep the rpms up above 2.5 for better climbing if I need it. I have the 8 speed and it does a good job on its own, usually. It’s hit 6th in 4L but I’ve never been over 30.

Center diff will give you traction if you have wheel spin in the front or back. It essentially sends 50% of power to the front and 50% to the rear. Rear and front lockers will split power left to right.

When you hit Ophir tomorrow, play around with all this stuff and drive whichever way makes you feel the most confident. I’m a few months into this platform and the first thing I did was hit up some dirt and run through all the settings, just to try it all out and see how to turn it on and off. First time using crawl control is really weird because it sounds like copulating robots.

Enjoy your drive tomorrow.
 
You’ll find the OBD reader extremely informative, at least I do. Long slow climbs in 4H will increase your torque converter temps, in 4L not nearly as much. A lot of this depends on several factors like your vehicle weight, tire size, and if you’re towing.

For me, airing down isn’t necessary for quick jaunts on regular forest service roads, or even long drives on regular good gravel forest service roads, you’re likely to see someone in a camera or Prius on those. Ruts, mud, sharp jagged rocks, big steep rocks things that you wouldn’t see a Camry or Prius on is air down potential.

Shift as needed. I find myself shifting on down hills to engine brake or on up hills to keep the rpms up above 2.5 for better climbing if I need it. I have the 8 speed and it does a good job on its own, usually. It’s hit 6th in 4L but I’ve never been over 30.

Center diff will give you traction if you have wheel spin in the front or back. It essentially sends 50% of power to the front and 50% to the rear. Rear and front lockers will split power left to right.

When you hit Ophir tomorrow, play around with all this stuff and drive whichever way makes you feel the most confident. I’m a few months into this platform and the first thing I did was hit up some dirt and run through all the settings, just to try it all out and see how to turn it on and off. First time using crawl control is really weird because it sounds like copulating robots.

Enjoy your drive tomorrow.
I much appreciate the input and you taking your time to give me this instructions. I will do as you say and try the different settings.
 
You’ll find the OBD reader extremely informative, at least I do. Long slow climbs in 4H will increase your torque converter temps, in 4L not nearly as much. A lot of this depends on several factors like your vehicle weight, tire size, and if you’re towing.

For me, airing down isn’t necessary for quick jaunts on regular forest service roads, or even long drives on regular good gravel forest service roads, you’re likely to see someone in a camera or Prius on those. Ruts, mud, sharp jagged rocks, big steep rocks things that you wouldn’t see a Camry or Prius on is air down potential.

Shift as needed. I find myself shifting on down hills to engine brake or on up hills to keep the rpms up above 2.5 for better climbing if I need it. I have the 8 speed and it does a good job on its own, usually. It’s hit 6th in 4L but I’ve never been over 30.

Center diff will give you traction if you have wheel spin in the front or back. It essentially sends 50% of power to the front and 50% to the rear. Rear and front lockers will split power left to right.

When you hit Ophir tomorrow, play around with all this stuff and drive whichever way makes you feel the most confident. I’m a few months into this platform and the first thing I did was hit up some dirt and run through all the settings, just to try it all out and see how to turn it on and off. First time using crawl control is really weird because it sounds like copulating robots.

Enjoy your drive tomorrow.

No right or wrong way to do it. I have an ARB dual + morrflate setup so airing back up is super quick to the point that it’s almost Never a bother to air down. My rig is heavy and airing down just makes the ride so much more comfortable.
 

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