Center Locked or Unlocked
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Bumbo
New member
Generally speaking you want to try and accomplish what you need to do without locking (center or axle)
Lock the center only if you have an issue with traction...
The biggest improvement for driving on that type of terrain is tires. Start there if you are having performance and saftey issues.
Lock the center only if you have an issue with traction...
The biggest improvement for driving on that type of terrain is tires. Start there if you are having performance and saftey issues.
Berty_K
Member
Watch this:
https://www.youtube.com/watch?v=jkiv-bWbLIo
To the best of my understanding, unlocked center diff would be closer to the CRV. Locked would be like the Ford.
A locked center diff would only be beneficial if you found yourself in a situation where either both front or rear wheels lost traction.
Feel free to chime in if I'm not totally correct.
https://www.youtube.com/watch?v=jkiv-bWbLIo
To the best of my understanding, unlocked center diff would be closer to the CRV. Locked would be like the Ford.
A locked center diff would only be beneficial if you found yourself in a situation where either both front or rear wheels lost traction.
Feel free to chime in if I'm not totally correct.
theoutbackdream
New member
You'll be better off having the correct set off tires, and disabling traction control. I wouldn't recommend locking the center diff just for that....
Bumbo
New member
Why would that not apply to both front passenger and rear passenger as well?
For example, if you pulled off the road into some icy/frosty shoulder, where you have both wheels on the passenger side slipping.
BackOff
New member
Not sure about the AWD like you have, I assume its the same... but with the 4wd V6, the center diff lock binds the steering, you can feel it in tight turns, like a pushing/scrubbing sensation.
I would not feel safe running it all the time. Like on the hwy.
I don't think its designed to be run all the time...I have been wrong before.
Try it for your self. lock it and make some tight turns in a parking lot, lots of friction to amplify the condition.
Bumbo said:
I used the cross up as an example, usually what stops ya. Traction on the same side usually pulls you through the 'stuck'.
Just from my personal experience.
Locking the center diff will cause binding on high traction surfaces when turning, since the front wheels have to travel further in a turn than the rears. So, always leave the center diff lock off on dry roads.
On snow and ice, it can be more of a judgement call. In general steering control will be better with the diff lock off, and you're less likely to "lose" the rear end, since the unlocked diff leaves each axle to find it's own speed and minimizes wheel slip in corners. With the diff lock on, you are forcing at least one wheel on either the front or rear to break loose and skid every time you turn a corner. That means you've lost half of your directional control on at least one of the axles. Generally that's not what you want.
Generally any diff lock is most useful when traction varies greatly from one wheel to the another. This is the often the case rock crawling (example: one wheel is lifted), but not nearly so much the case on snow/ice, where usually conditions are pretty similar from one side of the road to the other. In that case both axles are already doing their share of the work, and the center diff lock doesn't make a lot of difference. On the other hand, if you have the fronts on dry pavement and the rears in a snowy ditch (or vice versa), then yes, the center diff lock will help a lot.
I run my '06 with the center diff unlocked on snow/ice almost all of the time. I prefer the extra control and safety of the unlocked diff to the marginal extra traction of the locked diff.
Also keep in mind that, on the 4th gens, engaging the center diff lock defeats the VSC stability control. There are times when that is useful, but probably not the best choice under most high traffic snow/ice situations.
Going back to the OP's original question, it depends what is meant by "steep, nasty hills". If these are hills where the last bit of traction is required to make the grade, then yes, engage the center lock. Example would be a rural road with deep snow. If it's a high traffic road that's packed down into glare ice, the diff lock may help marginally, but you also risk losing complete control of the vehicle and going sideways. You need to be really careful with the power in those circumstances.
On snow and ice, it can be more of a judgement call. In general steering control will be better with the diff lock off, and you're less likely to "lose" the rear end, since the unlocked diff leaves each axle to find it's own speed and minimizes wheel slip in corners. With the diff lock on, you are forcing at least one wheel on either the front or rear to break loose and skid every time you turn a corner. That means you've lost half of your directional control on at least one of the axles. Generally that's not what you want.
Generally any diff lock is most useful when traction varies greatly from one wheel to the another. This is the often the case rock crawling (example: one wheel is lifted), but not nearly so much the case on snow/ice, where usually conditions are pretty similar from one side of the road to the other. In that case both axles are already doing their share of the work, and the center diff lock doesn't make a lot of difference. On the other hand, if you have the fronts on dry pavement and the rears in a snowy ditch (or vice versa), then yes, the center diff lock will help a lot.
I run my '06 with the center diff unlocked on snow/ice almost all of the time. I prefer the extra control and safety of the unlocked diff to the marginal extra traction of the locked diff.
Also keep in mind that, on the 4th gens, engaging the center diff lock defeats the VSC stability control. There are times when that is useful, but probably not the best choice under most high traffic snow/ice situations.
Going back to the OP's original question, it depends what is meant by "steep, nasty hills". If these are hills where the last bit of traction is required to make the grade, then yes, engage the center lock. Example would be a rural road with deep snow. If it's a high traffic road that's packed down into glare ice, the diff lock may help marginally, but you also risk losing complete control of the vehicle and going sideways. You need to be really careful with the power in those circumstances.
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RainyDayRunner
New member
I like what RonJR said and agree with all of that. I have heard that most people will leave the center diff unlocked when on snow and ice, until you get stuck. Having it locked will cause wheels to slip on any curve.
Also, VSC generally does a great job in the snow in 4HI. I guess you could test both ways and see which one you like better. Just do it when there is no other traffic.
Also, VSC generally does a great job in the snow in 4HI. I guess you could test both ways and see which one you like better. Just do it when there is no other traffic.
Inv4drZm
Senior Member
I assumed when they said hill they meant in a straight line. Of course never use and sort of diff lock when turning.
utahman11
New member
Something to consider, with the center diff locked, you wont get the power cutting out when you need to give it gas. See this video:
https://www.youtube.com/watch?v=qv5vtN46QuM this would be impossible without the center diff locked up because you need to goose the throttle.
https://www.youtube.com/watch?v=qv5vtN46QuM this would be impossible without the center diff locked up because you need to goose the throttle.
Bumbo
New member
There are ways to disable TRAC and VSC without locking the center... but yes, I have in the past locked the center specifically just to disable those things.
chili
New member
Some good advice here about when to use or not use the center lock. Best bet is to try it and see what works.
My two cents: after several winters driving 17 miles on backroads during blizzards (my commute to get to the plow truck), I've found I prefer running in 4Hi with the center locked. Yes, you tend to drift more, but I find the tendency to drift is more predictable, and 4Hi locked gives you the ability to power out of a slight drift, rather than get the power cut severely by traction control in 4Hi unlocked.
No matter what your preference ends up being, keep practicing in those conditions in a controlled environment (parking lot, etc) to see how your vehicle behaves in different modes. Driver skill is still the most important aspect!
My two cents: after several winters driving 17 miles on backroads during blizzards (my commute to get to the plow truck), I've found I prefer running in 4Hi with the center locked. Yes, you tend to drift more, but I find the tendency to drift is more predictable, and 4Hi locked gives you the ability to power out of a slight drift, rather than get the power cut severely by traction control in 4Hi unlocked.
No matter what your preference ends up being, keep practicing in those conditions in a controlled environment (parking lot, etc) to see how your vehicle behaves in different modes. Driver skill is still the most important aspect!
bob3dsf
New member
Having our trucks in 4Hi is essentially AWD because of the center diff. It can be driven on dry pavement in that setting (remember, a center diff., front and rear drive shafts are able to spin at different speeds... as in: during turns and curves). Locking the center diff. turns our trucks into a traditional 4x4 with just a transfer case (such as found on fords, chevys, or even tacomas, etc.). This setting will generate driveline binding if used on dry pavement.
Natter, if you are having traction issues on hills, there's no reason why you can't lock the center diff. However, if you still slip a lot in that setting, you don't really have any other help. If you try with the center unlocked (low gear, feathering your throttle, or even 4Lo), and you have trouble, locking the center gives you a "greater traction" option. Like others said, appropriate tires is a factor. And also, if you're slipping in 4WD and locked at the center, you'd probably be slipping with the center unlocked... in which case you should have picked a different route and you'll never get home now and it's time to go native...
Something else: remember the traction control is bypassed with the center locked. Like RonJR said, it's a judgement call based on conditions. I've found that 4Runner's traction control works VERY well. Every winter, when we get the weather for it, I go out to a school parking lot after hours, or somewhere else specific, to practice (and have a little fun) and see what the truck will do and what I can make it do. It's tough to get it to slip and slide with the traction control on.
I need to get my wife out with me to let her feel what slides feel like and what to do and what not to do. She's really nervous about that stuff. Better to have an idea of what's going on then not realize until its happening with traffic around.
Natter, if you are having traction issues on hills, there's no reason why you can't lock the center diff. However, if you still slip a lot in that setting, you don't really have any other help. If you try with the center unlocked (low gear, feathering your throttle, or even 4Lo), and you have trouble, locking the center gives you a "greater traction" option. Like others said, appropriate tires is a factor. And also, if you're slipping in 4WD and locked at the center, you'd probably be slipping with the center unlocked... in which case you should have picked a different route and you'll never get home now and it's time to go native...
Something else: remember the traction control is bypassed with the center locked. Like RonJR said, it's a judgement call based on conditions. I've found that 4Runner's traction control works VERY well. Every winter, when we get the weather for it, I go out to a school parking lot after hours, or somewhere else specific, to practice (and have a little fun) and see what the truck will do and what I can make it do. It's tough to get it to slip and slide with the traction control on.
I need to get my wife out with me to let her feel what slides feel like and what to do and what not to do. She's really nervous about that stuff. Better to have an idea of what's going on then not realize until its happening with traffic around.
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bob3dsf
New member
OK, but look at the side sliding while you're spinning. I'd argue that the lack of control there is a risk and potentially serious. Sure, by yourself, no big deal. Lots of room, just a few obstacles. If you need to climb without slipping and maintain a straight line you should be engaging 4Lo probably (or at least stay in 1st or 2nd gear if in 4Hi). If you're spinning, you have too much throttle. There is no traction when the tires are slipping.... like why you don't use the brakes (or VERY sparingly) when descending. You down shift and use the engine braking so the front tire can roll and allow you to turn and stay in control. I understand there are times you need to give it gas, but your video doesn't seem to be one of those times. Looks like playing around to me.... not that I'm against having some fun.
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JB.
New member
If you're already in 4wd, then lock/unlock is so quick and easy I see no reason not to if you think the situation warrants going all in on traction.
Btw, the steering effects of being center locked are much milder than is often assumed.
If you feel like nerding out. http://www.toyota-4runner.org/4th-g...pavement-center-diff-lock-vsc-off-switch.html
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