Axle? Can it break due to improper shifting??

Your front tractor axle has nothing to do with shifting. And everything to do where you put the tractor trailer.

And yes you can absolutely tear off a front steer. Ive done it.

 

Yes you can tear out the spline. OR take a bite out of any number of internal gearing.

The axles are steel forgings about 3 to 4 feet on each side 3 inches thick, the ones Ive seen. It will have a spline on one end for the center differental. Bolt end for the duals and bearings.

I have torn axles out of drives before when bearings were destroyed. The whole dual and axle assembly comes right out of the housing when you turn away from it making you 5 feet wider and a serious traffic hazard requiring a police response and tow to keep people from hitting it.

A incredibly simple pretrip procedure takes care of that possibility.

Stand against your duals from the outside with your knees. Bend over both duals towards the frame with your eyes. Look straight down the inner dual tire and it's parent wheel top to bottom vertically. IF you see ANY brake pad sticking out of it's edge of drum into your view or you see small metal rollers or twisted foil etc on the ground then that is your last warning before that axle comes out of there on your next turn.

A secondary symptom will be a loss of 50 to 150 RPM requiring you to add fuel with your foot to maintain a normal speed situation in any gear. It's a subtle problem you might not notice. But if you have been in that truck long enough the little problem will cause you to process the mental "Huh. what's this" while you sit there and wonder about it, out comes your tires and wheels.

 

Yes it can. Any impacts on drive train, especially over a time will stress things. Like..transmission, u- joints- rearends also driveshaft itself. Clutch also etc. A hard lift like out of a soft area of ground requires a smooth operator. Even just a hammer type driver/ operator, usually costs someone $$ in time. Used to pull coal out of the strip mines, alot of nasty pulls and hard lifts to get the loaded truck moving. Saw broken axles and some dropped driveshafts on steep hills. When the driver was trying to get moving again.

 

stillwurking refers to a form of battle in trucking when you have large weight. Versus runt engine. Sometimes things break because the engineeering on them is not strong. Actually delicate.

*SNAP.

Throw in cold weather say anything below -15 the steel is even easier to snap it becomes brittle like glass.

 

Excessive shock loads can break just about anything. Yes

 

It's not so much improper shifting as it is applying torque abruptly at the wrong time. This is most likely to happen loaded and under a wheel slip condition. It's not necessarily the shifting that causes the issues but how the torque is applied with the clutch engagement and the throttle.

I would say 3/4 of the power divider and differential failures we see are related to a shock load or spin out event and declined warrantable. Ussually splits a spider gear.

 

In failure analisis , old school books , had pictures. A shock like Goodysnap mentioned can also start a fracture but not fail. With more use the fracture continues to grow. The original fracture will be dark colored and the color will change as the fracture progresses. The fresh break is all bright colored.
I was blamed for abuse myself. I knew I did not and had to explain it.
Have torn up a whole lot more but do not blame me something I did not do.

 

Thats the bummer about slip seat in some circumstances. The person before you stresses , and cracks components, then it breaks on you. Salesman says"here is a cherry ride, driven by a mature gentleman" and the truck is sitt'in there still shaking, with it tongue hanging out.