A. Objects of the long axis type mounted on parallel supports. The heavy spot, as denoted here by the black dot, causes the object to be both statically and dynamically unbalanced. D. Long axis object ...

So your mechanic said your balance shaft gear is starting to wear out, and it got you thinking: What even is a balance shaft, and why do I need one? Do I need one? Is that even a real car part, or is ...