Triple lock not engaging

[mudgudgeon]

If you start trying to make turns on a high traction surface like concrete or asphalt you're going to get a lot of binding and tension built up in the driveline. Which can put a ton of load on your axles and other components. Which has the potential to break things.

If you have no understating of the concept of mechanical sympathy then yes.

If you're sensible, then driving your average rocky obstacle with a bit of right boot is gonna put a lot more strain on driveline than some sensible testing.

Toyota didn't build your drive train from glass

 

[Broski]

Front axle always locks faster
A hard surface will put a bind on the the drive line but unless you are trying to brake something ( really hammering the gas ) you won’t brake anything.
Another way to test the lockers is lock the center diff, chalk the tires & put it in neutral.
Then turn on the lockers jack up the rear passenger tire and spin it slowly, it should lock (stop) if you have both tires up off the ground they will both turn in the same Direction.
If the tire just spins then it not locking.
With the engine off key on you should hear a click in the passenger foot well when you turn the lockers on followed a winding noise at the actuator.
Good luck.
And keep us posted