Limited Slip Center Differential

[m85476585]

Does anyone know how strong the limited slip feature of the center differential is? If I go crawl up some rocks with it unlocked, will I eventually damage it? It seems like trying to climb a steep hill or rock with one or more wheels slipping is when the max torque is applied to the drivetrain. 4L, low gear, trying to get the wheel up a rock. Between the traction control on the brakes and uneven terrain, there could be sudden changes in wheel speed too.

I believe the center differential is Torsen, which supposedly never wears out, but is there any chance of wearing it out or breaking it? I guess I don't understand how they work.

When should I use the center lock? Are there times when I shouldn't use it (besides dry pavement, obviously)? Like full lock turns on a rocky trail, such as tight switchback or U-turn? It seems to resist moving if I do that. What if I have to do a full lock turn while crawling up a rock?

 

[Martinjmpr]

AFAIK the center diff is not a limited slip (corrections welcomed, but that is my understanding.)

If you're off road, just lock the center diff. :shrug: Don't know why you would want it unlocked anyway. The center diff is for the highway, not off road.

 

[JB.]

Does anyone know how strong the limited slip feature of the center differential is? If I go crawl up some rocks with it unlocked, will I eventually damage it? It seems like trying to climb a steep hill or rock with one or more wheels slipping is when the max torque is applied to the drivetrain. 4L, low gear, trying to get the wheel up a rock. Between the traction control on the brakes and uneven terrain, there could be sudden changes in wheel speed too.

I believe the center differential is Torsen, which supposedly never wears out, but is there any chance of wearing it out or breaking it? I guess I don't understand how they work.

When should I use the center lock? Are there times when I shouldn't use it (besides dry pavement, obviously)? Like full lock turns on a rocky trail, such as tight switchback or U-turn? It seems to resist moving if I do that. What if I have to do a full lock turn while crawling up a rock?

It's strong. Don't worry about being unlocked any time you like, but locked will give you maximum traction.

The Torsen center diff is mostly a luxury. Avail yourself of it whenever you like.

Personally, I'm spoiled by it.

Theoretically, using it often to avoid tight turns off-road might extend the life of certain drive train or steering components, but it's certainly not necessary. It actually does have some practical uses. If you have to turn around on a fragile surface, it will chew things up much less than when locked. Steering is more precise so, say, doing a slalom down a sandy wash while avoiding obstacles is more fun.

You paid for it, might as well enjoy it.

 

[JB.]

AFAIK the center diff is not a limited slip (corrections welcomed, but that is my understanding.)

Depends how the term is being used.

It's not a traditional limited slip but it qualifies under the general, descriptive term.

 

[philskeeter]

Depends how the term is being used.

It's not a traditional limited slip but it qualifies under the general, descriptive term.

I know having the center diff locked isn't good on a road you get good traction on like dry pavement because when you turn everything rotates at the same speed so it skips your tires etc. but I've also heard not to lock the center diff and even drive straight on a road with good traction because it will bind up your transmission up. Is this true?

 

[RPS13]

AFAIK the center diff is not a limited slip (corrections welcomed, but that is my understanding.)

If you're off road, just lock the center diff. :shrug: Don't know why you would want it unlocked anyway. The center diff is for the highway, not off road.

A torsen (as it's known in the US) or helical everywhere else in the world is definitely a limited slip differential.

The key distinction between it and the usual clutch-type salisbury diff that most think of when they think of an LSD, is that the helical diff will ONLY bias some multiple of the tractive effort from your LEAST tractioned axled. As in, fronts are on the slippery stuff, so they have 2 units of traction, if the diff biases at 3:1, you can only put 6 units of traction on the rear wheels. If the lower traction side slips, ALL power goes to it. So in a way, it can behave like an open diff under power under low traction situations.

The reason why they're used in street vehicles often is that they have little to no preload, and they tend to not "bind up" when biasing so they have low NVH. They also act like open diffs when off power, so they have good road manners for most driving people do.


I've done many laps on a race track with a helical diff in a high powered RWD car, so it's very obvious when it's doing its thing, or one tire (since it is biasing across the axle, not between two axles) has low traction.

 

[JB.]

...but I've also heard not to lock the center diff and even drive straight on a road with good traction because it will bind up your transmission up. Is this true?

In a word, no, unless you get into extremes of distance and speed (where you could create higher than normal diff temperatures).

Driving straight is nearly nothing. Making a street turn using 1/2 steering wheel revolution is not a lot more than nothing. It starts to turn into something fairly quickly beyond that, though.

Lots more info here.

http://www.toyota-4runner.org/4th-g...pavement-center-diff-lock-vsc-off-switch.html

 

[philskeeter]

In a word, no, unless you get into extremes of distance and speed.

Driving straight is nearly nothing. Making a street turn using 1/2 steering wheel revolution is not a lot more than nothing. It starts to turn into something fairly quickly from there, though.

Lots more info here.

http://www.toyota-4runner.org/4th-g...pavement-center-diff-lock-vsc-off-switch.html

ok that's what I thought and thanks for the link!