What situations do you lock you center diff?
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Desert Fox
New member
I lock the center diff in 4 hi when I am on a moderate trail. I move to 4 low when it changes to more of a difficult trail, either real rocky or steep.
My thinking is that stying in 4 hi helps keep the temp down. With the center diff locked I have not lost total traction.
Not a technical response but that is my experience.
My thinking is that stying in 4 hi helps keep the temp down. With the center diff locked I have not lost total traction.
Not a technical response but that is my experience.
http://www.toyota-4runner.org/4th-gen-t4rs/132842-new-4runner-4wd-vsc-help-please.html#post1271512
I use 4hi for general wet or slick conditions.
I lock the center diff whenever the road conditions are very, very slick (anticipating lots of tire spin), and it's severe enough that high speed driving is out of the question. Think about it, if locking the center diff can help you get out when you're stuck, then it'll help you not get stuck in the first place for the same mechanical reasons.
I use 4lo simply when I need high torque, or when I'm crawling in extremely rough terrain. When I off-road over snow covered terrain, I put it in 4lo with the center locked.
I use 4hi for general wet or slick conditions.
I lock the center diff whenever the road conditions are very, very slick (anticipating lots of tire spin), and it's severe enough that high speed driving is out of the question. Think about it, if locking the center diff can help you get out when you're stuck, then it'll help you not get stuck in the first place for the same mechanical reasons.
I use 4lo simply when I need high torque, or when I'm crawling in extremely rough terrain. When I off-road over snow covered terrain, I put it in 4lo with the center locked.
ridefast
New member
Center diff is locked
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03_4x4Runner
Senior Member
I off road a lot in the desert and rarely need the dif locked even on very steep loose climbs. If you drive in sand you will need to lock it so you can keep the tires spinning fast climbing dunes or driving through loose sand. Otherwise the traction controll puts the brakes on and almost brings you to a stop. I imagine mud would do the same thing.
Casper421
New member
The center diff locks on the fly, you dont have to stop to engage it.
Personally I think the center diff lock is a joke. It does disable VSC, but you still have traction control and ABS that think they can out drive you. It can create some scary situations on snow and ice because you start to slip and it wants to cut power when you need it most.
I understand not liking the traction control nannies, but why does that make the center diff lock a joke?
So at the 100% chance of sounding stupid. What exactly does the center diff do for me? I tried some searches but haven't looked too much.
On that note, when is 4 lo needed. I understand from searches not on pavement but when is the optimum time I would need that. I keep thinking I need to go use it to keep it from freezing up later.
On that note, when is 4 lo needed. I understand from searches not on pavement but when is the optimum time I would need that. I keep thinking I need to go use it to keep it from freezing up later.
The bulk of our trucks never get the center diff engaged or 4-lo activated. We are in the minority of drivers that nit-pick these computer aided traction devices. Most of these trucks never get off the pavement and these computer aided features are for the soccer moms of the world.
Essentially, locking the center differential prevents torque being sent to an axel with a slipping tire. Torque will be sent along the path of least resistance, which means if a tire has no traction, it'll get all the torque. See here:
Around The Corner (1937) How Differential Steering Works - YouTube
The video may seem a little cheesy at first, but very informative.
We have front and rear differentials that allow the tires connected on the same axle to travel at different speeds. The center torsen tranfer case is a differential and works using the same principle as the front and rear differentials. The center differential works with the driveshafts by allowing the front and rear axle to spin at different speeds. So when you "lock" the center differential, you are basically bypassing the center differential causing the front and rear drive shafts to spin together. Thus, locking the center diff doesn't allow slippage between the axels, which is bad if you're on a high traction surface like asphalt (driveline binding), but it's good if you're on a very low traction surface as one axel won't rob the other axel of power during slippage.
As for 4lo, you can use 4lo on regular roads. It's only locking the center diff that makes driving on asphalt bad. An example of needing 4lo on asphalt would be pulling a heavy boat out of the water on a very steep ramp.
4lo can be used for any low speed, high torque application. If you're rock crawling, for example, then you might as well put it in 4lo for the extra torque.
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08t4rlimited
New member
When roads are completely ice/snow covered...or off-road. Some people like to get stuck in 2wd, then try 4wd, then in 4wd-locked...I would rather put it in 4wd-locked and get stuck.......then I know I am screwed...
I am looking at it as a whole. If you could turn everything off and lock the center diff, I think it would be a valuable tool, but since it only turns off VSC I think it is a joke. Reason being is that even though it will lock in the power distribution, it doesn't help with abs and traction control kick in and start applying the brakes when you don't need it. I almost hit a curb the other day in the snow because when making a U turn I started to slide. Without the controls I would normally just stepped on the gas to kick it around instead I got a bunch of clicking and beeps while I headed straight for it. Luckily I stopped in time, but back to the point being that the center diff lock was useless in that situation.
medicrn
New member
That Is exactly my thought on it, though is a road has a lot of turns I don't lock the diff cus I'm worried about sliding sideways and I assume the vsc keeps that from happening. And I never use 4lo locked when stuck in snow, it just makes me think max torque when all 4 wheels slip is just a lot of wasted spinning
Think about what a rear differential does. It has an input shaft (the driveshaft) and two output shafts (the halfshafts). It transmits power from the input shaft to the two output shafts, but also allows them to turn at different speeds.
A center differential is basically the same thing, but with different geometry (and without the reduction gears). The center differential has an input shaft from the transmission, and two output shafts -- the front and rear driveshafts. The center differential transmits power from the input shaft to the two output shafts, but also allows then to turn at different speeds.
When you lock the center differential, the front and rear driveshafts turn at the same speed.
When you go around a corner, the path taken by the front of the vehicle is longer than the path taken by the rear of the vehicle. Therefore, the front driveshaft needs to turn faster than the rear driveshaft. If the center diff is locked and you are off road, the tires simply slip. But if the center diff is locked and you are on dry pavement, the tires can't easily slip and that can cause stress on the drivetrain. That is why you should not drive on dry pavement with the center diff locked (or if you do, why you should not go around corners).
As to when I lock the center diff, I fish on the beach every summer. I lock the center diff before I drive onto the beach. I don't normally lock the center diff on a snow covered road unless I'm going up a steep hill or the snow is very deep.
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scottm
New member
This time of year I lock it nearly every day on my way to work. I have to make a U-turn though the median (legal, that's how we have to make left turns in Michigan), and when it's snowy I can't do it with the traction control on. With center diff unlocked: I wait for a gap in oncoming traffic, hit the gas, and stut-stut-stutter across the highway hoping I make it before getting hit. With the center diff unlocked: I hit the gas and launch across, drifting nicely into the far right-turn lane with a little countersteering, and no complaints from my dashboard.
I do like the traction/stability control most of the time. I like driving and drifting, feel confident about my abilities, but my butt has been kept out of the ditch by stability control a few times on snow and ice.
I used to tow a trailer every day with my Land Cruiser, and I used 4-low unlocked when creeping back to hook up with the trailer. Now I use 4-low once a month or so just to make sure it still works.
I do like the traction/stability control most of the time. I like driving and drifting, feel confident about my abilities, but my butt has been kept out of the ditch by stability control a few times on snow and ice.
I used to tow a trailer every day with my Land Cruiser, and I used 4-low unlocked when creeping back to hook up with the trailer. Now I use 4-low once a month or so just to make sure it still works.
