whats with the center diff lock?
08-16-2006, 05:24 PM
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whats with the center diff lock?
a guy at work just bought an 06 4runner and asked me some ?'s about his 4wd. I was wondering why the hell it beeps CONSTANTLY when in 4lo? i hope we did something wrong cause that would str8 piss me off!
also, i have the rear locker in mine and his is a center diff lock? what exactly is that gonna do? when to use it? and benifits / drawbacks versus the rear locker?
i wouldnt imagine it locks both axles but i have no clue.
also, i have the rear locker in mine and his is a center diff lock? what exactly is that gonna do? when to use it? and benifits / drawbacks versus the rear locker?
i wouldnt imagine it locks both axles but i have no clue.
08-16-2006, 05:30 PM
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im pretty sure it locks the two together, as ours are all the time, otherwise with center diff lock disengaged it can be used as full time 4wd... aka awd. Ive always understood that the differance between true 4wd that cant be used all the time and AWD is that it doesnt have a center diff
08-16-2006, 05:46 PM
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Originally Posted by wjwerdna
im pretty sure it locks the two together, as ours are all the time, otherwise with center diff lock disengaged it can be used as full time 4wd... aka awd. Ive always understood that the differance between true 4wd that cant be used all the time and AWD is that it doesnt have a center diff
08-16-2006, 05:49 PM
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ok, so is it better to have this center differential? when would one want to use it? he doesnt plan on taking it on the trails AT ALL (im working that issue) but we are in chicago and the winter can dump a foot of snow in a matter of time on any given day. would he have the need for this?
and the beeping in 4lo, WTF?!!! can we turn it off, something?
and the beeping in 4lo, WTF?!!! can we turn it off, something?
08-16-2006, 05:58 PM
#5
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ok, with your vehicle (completly ignore RRDIFF LOCK, as its not related) it is advisable to NOT drive around with 4wd engaged all the time especially on dry pavement, because the drivetrain binds up between the front and the rear axles... to get rid of this binding, you need to have a center diff, so yes, in my opinion it would seem to be better to have a center diff (its actually a third in addition to front and rear right?). When locked i believe it acts the same as your vehicle (disregarding the rear diff lock)
08-16-2006, 06:08 PM
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kinda makin sense now. so when he engages 4wd in his 06, it aplies it when needed? if he locked the center diff it will make it full time 4wd, and when he unlocks it, back to kinda traction control-ish distributing power to wheels as needed?
any answers on the beeping comp when in 4lo? is it gonna be a fact of life?
any answers on the beeping comp when in 4lo? is it gonna be a fact of life?
08-16-2006, 06:11 PM
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i dont know about the distributing power thingy, but that seems like it may be a valid way of describing it... no idea on the beep though, sounds like dumb option 
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08-16-2006, 06:17 PM
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man, you should here the dang thing. everysecond an annoying a$$ beep, beep goes off! it added to the frustration and i was fed up rather quickly! (also due to the fact i didnt know what i was talking about, as i have become quite a little reference for vehicle maintenance at work due to this site!)
08-16-2006, 06:26 PM
#9
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yeah, i'll have someone ask me a question on something one day, not know anything about it, and then the next day be able to tell them everything they would ever need to know when doing it, what parts they would need, tools, where to get the manual, etc etc
08-16-2006, 06:40 PM
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Originally Posted by tbrown78 - tundrasolutions.com
It shouldn't beep in 4 low. That beeping means that 4 low is not engaged. To shift into 4 low you have to stop and shift into "N". Then you can shift to 4 low. Like I said though you shouldn't be beeping while in 4 low. Mine only beeps if I forget to shift into "N" before trying to shift into 4 low. Check your manual it tells you how.
sounds like this may be the same thing... but in a different toyota
this also describes a little -> http://www.tundrasolutions.com/forum...hurr-way-stop/
08-16-2006, 06:41 PM
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http://www.offroaders.com/info/tech-...eading/4wd.htm
When a 4WD is traveling in a straight line all four wheels rotate at the same speed, but during cornering each wheel travels at a different speed due to the radius of the turn. All vehicles have a differential on the front and rear axles to allow the wheels on the same axle to rotate at a different speed. Constant 4WD’s have a central differential fitted to allow for different speeds between front and back wheels, but most part-time four wheel drives do not.
When a part-time 4WD (without a center differential) is in 4WD an attempts to corner on bitumen, all wheels need to rotate at different speeds, but without a centre differential they cannot. This creates the phenomena called "axle windup" or "transmission windup". High strain is placed on the drive shafts and transmission, eventually causing one of two things to happen. Either one of the wheels slips or spins to overcome the stress or the drive-shaft/transmission breaks. This is why part time 4WD’s should never select 4WD on paved surfaces.
Constant 4WD’s have a central differential within the transmission to overcome this problem. However once in the dirt a constant four wheel drive can be bogged with only one wheel spinning. This is why they have a central differential lock that stops the action of the center diff and makes it like a part-time four wheel drive in 4WD mode. The center diff lock should never be used on paved roads or non-slip surfaces for the reasons mentioned above.
In reality, a 4WD is only a two wheel drive with one front and one back wheel driving when traction is lost. One wheel on each axle spins while the other receives no drive at all due to the action of the differential. The exception to this is when a limited slip or locking differential is installed. A limited slip diff allows a limited amount of drive to be applied to the stationary wheel before the other wheel on the same axle spins. A locking diff allows no slip at all and both wheels on the same axle turn at the same speed, regardless of the amount of traction.
When a 4WD is traveling in a straight line all four wheels rotate at the same speed, but during cornering each wheel travels at a different speed due to the radius of the turn. All vehicles have a differential on the front and rear axles to allow the wheels on the same axle to rotate at a different speed. Constant 4WD’s have a central differential fitted to allow for different speeds between front and back wheels, but most part-time four wheel drives do not.
When a part-time 4WD (without a center differential) is in 4WD an attempts to corner on bitumen, all wheels need to rotate at different speeds, but without a centre differential they cannot. This creates the phenomena called "axle windup" or "transmission windup". High strain is placed on the drive shafts and transmission, eventually causing one of two things to happen. Either one of the wheels slips or spins to overcome the stress or the drive-shaft/transmission breaks. This is why part time 4WD’s should never select 4WD on paved surfaces.
Constant 4WD’s have a central differential within the transmission to overcome this problem. However once in the dirt a constant four wheel drive can be bogged with only one wheel spinning. This is why they have a central differential lock that stops the action of the center diff and makes it like a part-time four wheel drive in 4WD mode. The center diff lock should never be used on paved roads or non-slip surfaces for the reasons mentioned above.
In reality, a 4WD is only a two wheel drive with one front and one back wheel driving when traction is lost. One wheel on each axle spins while the other receives no drive at all due to the action of the differential. The exception to this is when a limited slip or locking differential is installed. A limited slip diff allows a limited amount of drive to be applied to the stationary wheel before the other wheel on the same axle spins. A locking diff allows no slip at all and both wheels on the same axle turn at the same speed, regardless of the amount of traction.
08-16-2006, 06:47 PM
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When the center diff is locked power is split 50/50 between front and rear diffs. If it beeps all time in 4lo something is wrong. Did he stop completely and shift into neutral before engaging 4lo?
08-16-2006, 06:53 PM
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Originally Posted by Mikestang
When the center diff is locked power is split 50/50 between front and rear diffs. If it beeps all time in 4lo something is wrong. Did he stop completely and shift into neutral before engaging 4lo?
08-17-2006, 07:27 AM
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Well it beeps if something is wrong, and as long as he's not moving and in neutral when he engages there shouldn't be a problem. Sounds like a trip to the dealer is in order.
08-17-2006, 07:42 AM
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It's been a while since I have used 4 Lo, but I believe it may beep if the Downhill Assist Control feature is activated. Look at the dash to see if the green warning light for the DAC is on, or be sure to check the switch located in the center console area to make sure that it is turned off.
It is pretty easy to accidentally depress this switch, but I don't know if it beeps while in 2WD or full-time 4 Hi because I think this feature only works in 4 Lo.
It is pretty easy to accidentally depress this switch, but I don't know if it beeps while in 2WD or full-time 4 Hi because I think this feature only works in 4 Lo.
08-17-2006, 07:52 AM
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I know the beeping your talking about. You HAVE to make sure you are stopped and in NEUTRAL before you engage the 4-LO. I spent 20 minutes to trying to figure this out one day. beep beep beep beeep....... 
08-17-2006, 10:38 AM
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Like everyone else, here's exactly what I do...
In 4Hi...
Stop...
Shift Neutral..
Switch to 4Lo..
Shift to 1st or 2nd or whatever..
Go.
You should only have to be in neutral for a split second until the orange light stops flashing (I think orange).
When getting in or out of 4Lo, if you get out of neutral too quickly or w/o stopping it will beep.
BTW, all this above is only for the case of you attempting to get into 4LO and failing.
Did you KNOW you were in 4LO? Because if you are in it and it's beeping that's a completely different story. You should know it because you'll max your speed out at about 12mph, and the shifts will feel like someone is rear ending you.
In 4Hi...
Stop...
Shift Neutral..
Switch to 4Lo..
Shift to 1st or 2nd or whatever..
Go.
You should only have to be in neutral for a split second until the orange light stops flashing (I think orange).
When getting in or out of 4Lo, if you get out of neutral too quickly or w/o stopping it will beep.
BTW, all this above is only for the case of you attempting to get into 4LO and failing.
Did you KNOW you were in 4LO? Because if you are in it and it's beeping that's a completely different story. You should know it because you'll max your speed out at about 12mph, and the shifts will feel like someone is rear ending you.
