Center Diff Lock vs Diff Lock
- Thread starter Hongster
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aha2988
New member
no that is not correct,
So to break it down..
Your engine turns the transmission, which transfers power from the engine to the axles. the transmission only has one output shaft so we put this thing called a transfer case behind it.
the transfer case thus turns when the tranny turns which then turns the rear drive shaft.
when you select the 4wd option, or if you are always in all wheel drive then your transfer case is turning the front drive shaft to.
so your heading down the road and all of a sudden you have to make a turn. the transfer case at this time is turning the front and rear drive shaft at the same speed. So now our transfer case has to act as a differential, differentiating the power and speed between the front and rear axle. Thus allowing the front axle to spin slower than the rear axle as it has to make fewer rotations than the rear axle to navigate through the turn.
Now after you've made that turn you've found yourself on a slippery icy road that heads up hill.
If your transfer case is still aloud to differentiate power between front and rear at different speeds, as your tires start to lose traction the power will be transferred to the axle with the least resistance. Just like when you were navigating the turn the front axle started to bind up so the transfer case let go of the front drive shaft for bit sending most power to the rear axle. In the icy hill climb situation you need to send equal power to the front and to the rear axle so that they both pull the vehicle equally up the hill. As opposed to the rear axle get all power and slipping and sliding or the front just spinning without any power going to the rear.
so they put a shift fork in the transfer case that when selected to shift into place by the center diff locker switch, it then locks the gear sets in place so that power coming from the transmission is split 50/50 50% goes to the rear and 50% goes to the front.
The axles at this point both receive the same power but they are receiving the power though their own individual differentials, that then split the power again sending power to the individual wheels. Like the front and rear axle must differentiate speeds in a turn the right and left tires have to differentiate speeds going through a turn. However, when one of those tires on the axle loses traction, all the power sent to that axle will then become transferred to the wheel with the least resistance (or the tire without traction) This is where you find in slippery situations just the front left tire spinning or just the back right tire spinning.
To correct that issue in slippery situations you have to get an aftermarket locking differential and install them in place of the factory open center differentials, in the front and rear axles themselves.
So the Center diff locker forces both driveshafts to spin at equal speeds but not all 4 tires. to get all 4 tires to turn at the same speed at all times would require aftermarket differentials.
hope this clears things up a bit.
So to break it down..
Your engine turns the transmission, which transfers power from the engine to the axles. the transmission only has one output shaft so we put this thing called a transfer case behind it.
the transfer case thus turns when the tranny turns which then turns the rear drive shaft.
when you select the 4wd option, or if you are always in all wheel drive then your transfer case is turning the front drive shaft to.
so your heading down the road and all of a sudden you have to make a turn. the transfer case at this time is turning the front and rear drive shaft at the same speed. So now our transfer case has to act as a differential, differentiating the power and speed between the front and rear axle. Thus allowing the front axle to spin slower than the rear axle as it has to make fewer rotations than the rear axle to navigate through the turn.
Now after you've made that turn you've found yourself on a slippery icy road that heads up hill.
If your transfer case is still aloud to differentiate power between front and rear at different speeds, as your tires start to lose traction the power will be transferred to the axle with the least resistance. Just like when you were navigating the turn the front axle started to bind up so the transfer case let go of the front drive shaft for bit sending most power to the rear axle. In the icy hill climb situation you need to send equal power to the front and to the rear axle so that they both pull the vehicle equally up the hill. As opposed to the rear axle get all power and slipping and sliding or the front just spinning without any power going to the rear.
so they put a shift fork in the transfer case that when selected to shift into place by the center diff locker switch, it then locks the gear sets in place so that power coming from the transmission is split 50/50 50% goes to the rear and 50% goes to the front.
The axles at this point both receive the same power but they are receiving the power though their own individual differentials, that then split the power again sending power to the individual wheels. Like the front and rear axle must differentiate speeds in a turn the right and left tires have to differentiate speeds going through a turn. However, when one of those tires on the axle loses traction, all the power sent to that axle will then become transferred to the wheel with the least resistance (or the tire without traction) This is where you find in slippery situations just the front left tire spinning or just the back right tire spinning.
To correct that issue in slippery situations you have to get an aftermarket locking differential and install them in place of the factory open center differentials, in the front and rear axles themselves.
So the Center diff locker forces both driveshafts to spin at equal speeds but not all 4 tires. to get all 4 tires to turn at the same speed at all times would require aftermarket differentials.
hope this clears things up a bit.
Last edited:
robaroni
New member
So who make these aftermarket locking differentials?
aha2988
New member
Several different companies. As well as different styles ARB has a selectable locker that's powered by air, Toyota offers a factory rear locker that's electronic, TJM offers an air locker. Other companies make options such as mechanical lockers that engage whenever one wheel spins faster than the other on the same axle. Then there are also full time lockers that are called spool lockers they are not selectable. Lots of info on the Interweb about all the options.
Hongster
New member
Oh man thank you for the technical details. I've got it all wrong all this time.
Wonder if True-Trac makes 4runner differentials.
Thanks again very much, I've been educated!
If you want locking differentials, get ARB. But unless you are doing serious offroading, you don't need them.
aha2988
New member
True trac does have diffs for our trucks
