“Take the props off, grease the shafts, and check the seals,” Fessenden said. Zeus propeller shafts use a double-lip seal. If the outer seal is damaged by debris, fishing line or rope, only the inner seal separates the pod’s innards from seawater. “Look for signs of corrosion.” Zeus has two zincs attached to each trim tab. Volvo has one zinc hidden, but accessible, on the drive itself. “If you seem to be going through zincs quickly, call an electrician,” Fessenden warned. Use Volvo or Cummins zincs too, which aren’t zinc at all. Cummins uses aluminum-gallium anodes to best protect bronze drives.