This metal-rubber bushing isolates vibration between the sieve frame and its mounting point in the cleaning unit. It absorbs oscillatory loads from the sieve drive, preventing metal-to-metal contact that would transmit noise and cause fretting wear at the attachment holes. The rubber element compresses under load to maintain alignment while allowing the limited angular movement required by the sieve’s reciprocating motion. When the rubber hardens or cracks, the bushing loses its damping ability, leading to increased frame stress and eventual bolt loosening. On replacement, ensure the bushing is fully seated in the bore and that the mounting bolt is torqued to specification.