Dump truck locking differential?

[RayCo]

Anyone here have familiarity with a triaxle dumptruck? I had one out at my house the other day, and the driver had trouble getting out of my driveway because of the steep incline and the fact that it's gravel. After a few tries of just spinning the tires, she backed down and did something, and then just smoothly pulled out. I'm just curious as to what the driver did here. Engaged another drive axle? Locked the differential(s)? Here's a video:

YouTube - Dump Truck Traction Control

Whatever it is, it made me want to drive the truck.

 

[art]

Most big trucks only drive with one wheel per axle. You have options like locking both potential drive axles together as well as locking the wheels on an axle.

 

[LarryRB]

The driver engaged what they call a power divider

 

[LarryRB]

The driver engaged what they call a power divider

 

[plowking]

My Freightliner has a power divider,my truck is worse because it has air ride suspension and the articulation between axles isn't good. I have to lock in going over small depressions at driveway aprons,or truck sits there and the wheel in air spins. The divide has a toggle switch on dash ,it is air activated down to the control located on front of forward axle to lock the differential. I also have a normal or mud,snow switch,older trucks called it a wet or dry road switch. My truck also will reduce my throttle if wheel spin light comes on. Truck has electronics,computer that controls the wheel spin functions. On a tri-axle if the lift axle is down or doesn't lift high enough,it will take weight off the drive axles,causing it too lose traction. Some third axles are air up,air down or spring up, air down. plowking

 

[Renze]

Most european dumptrucks have rear tandem, and dual front steer axles.
Each axle has a diff, and inbetween front and rear is a diff. All can be locked.

I dont know what the diff configuration on a tridem rear with single front axle is though.... You dont see that configuration in Europe that much, either dual front steer with tandem, or single front, tandem and a steered and driven follower