618 Idler/Idler Arm Issues

[adamlwells]

When I engage the PTO on my Grasshopper 618, the idler arm starts to shake rather violently. I have to disengage the PTO. Any ideas on what might be the root cause?

Thanks in advance.
Adam

 

[bertsmobile1]

blades out of balance

 

[adamlwells]

As a point of clarification, I’m referring to the PTO idler, not the mowing deck idler.