Why can't Fluidampr or Streetdampr be spun on a balance machine?

Balancing a crankshaft with the Fluidampr or Streetdampr is not recommended. The Fluidampr (or its damper ring) and the Streetdampr contain an inertia ring that can rotate inside. This inertia ring is balanced to very close tolerance specifications at the factory but may not be to perfect "zero" balance. When the damper is spun on a balance machine, this inertia ring may rotate inside the damper and the operator may be chasing this small imbalance while attempting to balance the crankshaft.

When the damper is installed and run on a combustion engine, the shear forces on the silicone fluid inside the damper from the torsional moments of the engine crankshaft, centers the inertia ring on its bearings. A balance machine does not generate torsional shear forces and the inertia ring may not be completely centered in its bearing clearance gaps.( IT WILL BE CENTERED AND IN BALANCE WHILE RUNNING ON AN ENGINE )