How does a locking center diff and a lunchbox locker interact?

[gimlithepirate]

See title for my question. I used to drive an Isuzu Rodeo, and lots of people were fond of putting lunchbox lockers in the front axle, so it would only engage when it was put in 4WD. That made me think, what is the effect of our center locking multi-mode diff on lunch box lockers? Lunchbox lockers are supposed to lock when power is applied from the driveshaft, so my thought would be if you started to slip in 4Hi unlocked, all the power would go to that axle (to the split of the limited slip) and the lunchbox would engage. This would seem to be a potentially bad thing on ice/snow.

Just trying to wrap my head around it.

 

[Inv4drZm]

See title for my question. I used to drive an Isuzu Rodeo, and lots of people were fond of putting lunchbox lockers in the front axle, so it would only engage when it was put in 4WD. That made me think, what is the effect of our center locking multi-mode diff on lunch box lockers? Lunchbox lockers are supposed to lock when power is applied from the driveshaft, so my thought would be if you started to slip in 4Hi unlocked, all the power would go to that axle (to the split of the limited slip) and the lunchbox would engage. This would seem to be a potentially bad thing on ice/snow.

Just trying to wrap my head around it.

With the center diff unlocked and rear diff locked, all the power would either go to one of the front CV's or through the rear driveshaft, whichever had the least traction. 3 Options. It would likely be one of the front CV's with the least amount of traction as the rear has two tires giving it more opportunity for traction. So its basically worthless with the center diff unlocked and probably won't ever engage.

 

[gimlithepirate]

With the center diff unlocked and rear diff locked, all the power would either go to one of the front CV's or through the rear driveshaft, whichever had the least traction. 3 Options. It would likely be one of the front CV's with the least amount of traction as the rear has two tires giving it more opportunity for traction. So its basically worthless with the center diff unlocked and probably won't ever engage.

That makes sense. The reason I was trying to figure it out is it might be a poor man's selectable locker if it only engaged when you locked the center diff. Most of the time if I'm locking the center, locking the rear axle would not be a bad thing at all.

 

[T4R2014]

The path of least resistance. Likely one of the wheels in the open rear diff.