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TundraGeneral discussion forum for the 2007 and later Toyota Tundra.
This is a discussion thread titled "4wd: Why you may need 4L vs 4H", within the Tundra forum, part of the Truck Forums category.
If you are an avid off roader and have lifted your tundra and run larger than stock off road tires and actually use em getting yourself stuck, you already know most or all of what I am talking about. If you look at the dial and ask yourself what 4L does, then you might pick up some valuable information.
I just read a thread about someone getting stuck by shifting to 4L out of neutral and thinking that the truck was not functioning correctly. I would bet that many 4wd owners have a very poor idea of the actual workings of a low range or the purpose for it, so I figured I would toss in my 0.02 (Canadian, so thats about 0.02, with some extra tax in there).
I don't remember the exact low range gear ratio, I believe it is 2.62-2.65 (bet msxjw is the first to get the right number), which basically means that an additional set of gears are multiplying the torque by 2.62-2.65 at the cost of rotational speed. All 4H is doing is sending power to the front wheels as well as the rears where 4L is giving you FAR more pulling and climbing power. Most 4L systems (all the ones that i have used) will drastically cut how fast you can travel, if you want over 30-35 mph, 4L is a very bad plan (most circumstances for 4L should be around 5 miles per hour or lower in my experience, unless you count competitive rock crawling style off roading, the tundra is very poorly suited to that task).
You will also find that while in 4L your motor will rev a lot higher based on how you will be using it, especially with the 6 speeds having a 3.33 (1st) ratio and a 4.30 rear end. When those two ratios are combined with a 2.62 low range, 37.5 crank rotations are required to turn the tire once so at 3750 rpm, you will turn your wheels 100 times in one minute. Your tire size will change your speed, but you will not be moving very fast at 3750 rpms in first gear. I have never felt the need to be any higher than 2nd gear in any low range in my life, but others might have come across a reason that they can post on. I have always found that if you want to go fast and spin your wheels, the slowest setting that you have, is not the way to go.
As to WHY you would be in 4L in no particular order:
1: Pulling a stuck vehicle out of a ditch, mud or snow when you have solid traction and a static tow line like a chain. Bungie tow straps require you build momentum and therefor 4H will usually be ideal.
2: Climbing very hard (rock) and steep grades where traction is not heavily compromised. Little note about traction, if you don't have it, 4L is pointless and you may as well be in 2wd or walking.
3: Entering truck pulls, 4L on a tundra can drag 40,000 lbs rigs nearly as far as many stock diesels, youtube it to see. Cool thing to do, very hard on the vehicle when you start to hop the drive train. The 40,000 lbs is not too much to pull with 4L if its hooked up correctly, its just illegal and not practical, its when they shift the load forward and the towing truck starts violently shaking and bouncing that its not such a great idea. Its a result of too much torque on the wheels breaking traction and causing the tires to hop and spin. Semi's will do this on steep grades with too high a load for the rated grade, and its a common problem on gravel or dirt roads.
4: Pulling stumps, tearing up cables or some other tractor type task where a low speed and huge torque is required. Tractors are better at pulling then a tundra largely because of the tires giving them the ability to put the torque to the ground with those big tires. Although every farmer with half of a brain will not think of replacing a tractor with a tundra, no matter how crazy the commercials get.
5: Driving very slowly without using brakes, massive downhill grades ( like 20 percent for starters) off road are taken more safely in 4L and you don't wear your brakes, same effect as using manual control to restrict max gear, just multiplied by 2.62-2.65.
6: Letting Britney Spears have a toddler drive on her lap, because a crash in 4L is safer because of the lower speeds, and thus the airbag might not kill her kid when she tailgates someone, I am pretty sure thats why the engineers put a low range in any truck these days. Britney Spears seems to be everywhere, so you have to be ready for it.
The odds are very good that you do not need 4L "almost ever". 4L is not going to change traction, thats your tires job, and your job for knowing when they aren't going to be enough. If you are slipping backwards while trying to climb a hill, a higher speed approach is usually the answer, or a bigger problem if you fail to crest the hill. The most fun i have ever had while at work with a truck was climbing a snowy grade at full tilt pace in 4H, 4L was hopeless. Each time I would try and climb out I would just fail to crest the curve, only to slide a few hundred feet back and have to do this about 7 more times until the duramax got me out. Good thing I had to go down this road 5 more times in the course of the work, each time with a similar result until the mine site operators got around to sanding the access road. I was the only guy lucky enough to use the road, and 777 haul trucks bringing in the cash get the priority with sanding.
I regularly use my truck on mine sites, construction projects and exploration "roads" that are basically the mess that a bulldozer leaves behind after a few passes through the forest. I have towed out a number of vehicles, I have engaged 4L about 15 times in 30,000 miles, of those 15 times, 6 were probably "almost" absolutely required to climb the banks on deep creek crossings. The reason 4H would be a bad idea is because approach speed would be needed to have the momentum to climb out, leaving me short one bumper. The climb down has cost me a few 7/4 pin harnesses so far, they should be in the tow crossmember, not hanging under them, but thats another story.
Last piece of advice, if you are stuck in 4H, odds are 20:1 that 4L is not going to change the situation for you. 4H and wheel spin sometimes breaks you free, or if you can still move, slow rocking back and forth can track a path out when in the mud and snow, but chances are if you think you are stuck after a few short minutes, you probably are.
If you plan on going somewhere you think you can or might get stuck consider the following:
another person and another vehicle
a shovel
chains, towstraps or both (make sure they have a high enough rating for the task, it will be 1000's of lbs if you are wondering)
an off road jack stand (factory jack is nice for tire changing, not nice to try and lift a truck 2' in the mud).
Come along hand cranked winching systems
Powered winchs
5 gallon pails
Survival gear dictated by region, I run the occasional risk of breaking down 200 miles from the nearest inhabited human dwelling at subzero temperatures, but i wouldn't suggest an arctic sleeping bag as standard 4x4 gear.
Yukon - nice write-up on the subject. Just to add my .02 (American) - I have had several (GM) 4wd vehicles over the years and most recently had an AWD SUV (GM). It is the worst design ever. I found out that the torque is not evenly split between front and rear until the rear starts to slip, then it shifts more to the front. As you can guess, this works poorly in most slippery conditions like snow and ice. I much prefer standard 4wd/2wd with 4L and 4H options. I would advise all to avoid AWD except some foreign vehicles with balanced torque designs like Audi.
this is a very good write up, being a 4wd novice here in soCal, i rarely use the feature. but I have one question for you, My tundra was bought to haul my 5000lb travel trailer,
which I like to put into remote campsites, and sometimes with my old vehicle,
it just didnt have the torque to push the trailer up the hill into the campsite. I dont know if it will hurt the trany to shift to 4wd low, and back it up into a steep site (usually the best ones), in a case where traction isnt the problem but low speed torque is.
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2008 crewmax 5.7 limited trd
2004 Tacoma dblcab trd
2005 Pilot
1999 I-30
1997 bmw 28i
If you want to push your trailer up a hill in reverse with 4L you would be totally fine doing so. I took the bend out of a bumper on an old F-250 pickup truck with a telephone pole and low range by pushing into it. Don't tell the local telecom on me, they really gouge on prices, and i am pretty sure the pole was ok. You can use low range for anything that you want to, all you are doing is upping the torque and dropping your speed. Hell, I have seen people use low range to make tiny adjustments when hooking up to a trailer, its easier to inch back that way, and if the chaulks came out the trailer would not boss your truck around on a hill. Its a bit much if you ask me but there is no harm from it.
Just read the card in your driver side visor on how to switch in and out, sometimes you may need to roll forward a bit if it doesn't grab in neutral, it will flash and chime if something is stopping it from going in. If you own a 4wd its always a good idea to try all of the 4wd settings before you need them. Some systems can hit a position on the gears that won't switch until moved forward or backwards just a bit, this can be a problem if stuck in 2wd and you need to get 4wd working.
Good rule of thumb, have it in 4wd before you think you need it off road, some obstacles require you to carry your momentum to get through, if you come to a stop to fiddle with 4x4 options you may get stuck whereas hammering it with just 2wd would carry you through.
Best advice I can give, if you are going offroad and are looking at a hazard, think of worst likely way to get stuck, decide if you are ok with dealing with it, if you are ok with being 3 feet deep in mud, or shoveling 1000lbs of snow then commit to it and gas it until you clear it or until you are 50 feet in with a tow line and a buddy that you owe a beer to. If you are worried about breaking things, buy an old ratbag uninsured rustbucket and flog that sucker, tow it in and out. In highschool my friends and I chipped in on a late 70's toyota pickup with 33" tires and more rust than body.
That old beater provided more offroad entertainment per dollar than we could have ever asked for. We jumped it, crashed it, rolled it, sunk it under water and had to tow it out 400 feet down river and it never did stop working, we only had compression on 3 cylinders at the end and it lacked the power to get up big grades on its own. There is sheer pleasure in offroading when you really couldn't care less what happens to any part of the vehicle, and if you want bed bounce, try staggering train tracks as fast as your bones will let you go, thats a harsh ride.
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Parked it too far in the snow going on about 4 times now, nothing a shovel and an overused profanity hasn't been able to fix.
Times pulled out zero, I am afraid I may need to bend down to reach a towhook to get pulled.... thanks cardata video, you helped me dodge a bullet.
Yukon Tundra, you sound like a man of experience(read, BT,DT). Best remark, "Put in 4WD before you think you need it". Because once you're stuck, brother, you're probably stuck for good. You need to plan for that. I never hesitate to use 4Lo when low speed pulling power is required. Why stress the drivetrain & lsd using too high a gear? As far as pushing that trailer, if that's on a hard surface just make sure you do not need to turn the front wheels. Going straight for a short distance would be OK. I pulled an Exploder from the mud recently. I let him crawl under his & hook up the chain(Hey! I'm not the one who got stuck). Put the Tundra in 4Lo & eased him right out. Go out & get stuck enough. You'll learn. Makes for good stories. Nice post, YT.
Steep downhill, with heavy trailer load, and NO trailer brakes is another time you'll appreciate 4L. Not a good idea to pull such a thing without trailer brakes, but I've been there... scares the sh** out of ya. Note to self: NEVER do that again.
4wd: Why you may need 4L vs 4H
TUNDRA786
Re: 4wd: Why you may need 4L vs 4H
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