David Heberling

Torsional vibrations are SERIOUS vibrations

Why? Because when you vary the speed of a drive shaft, you not only vary the torque on all of its components, but you vary the torque on all of the components that are connected to the drive shaft Torque is LOAD.

When you vary the load, at twice per revolution, you start to bend components.

You know what happens then……the same thing that happens when you bend a can lid back and forth. IT BREAKS.

you don't know what your talking about BGarofalo  .when drive shaft is out of phase it makes it jerk two time every turn.  my new truck the drive tires only lasted 36000 miles because of this. and has tor up my hole drive line.  volvo and mack needs to recall this junk.

my truck came from volvo this way . i no a guy one year old mack same problem .   i no a guy one year old volvo same problem

volvo and mack trucks   DRIVE SHAFT OUT OF PHASE!!!! AND DON'T STAND BEHIND THEM