Full definition
Excessive clearance between mechanical components such as bearings, couplings, baseplates or anchor bolts that allows unwanted movement. Generates vibration spectrum with multiple harmonics (2x, 3x, 4x RPM) and subharmonics (0.5x). Types: structural looseness (bases), rotor looseness (shaft-bearing) and induced looseness (wear). Diagnosed with vibration analyzer. Correction: torque bolts to specified values, replace bearings, repair bearing seats.