Replacing Soundown Coupling Thrust Element

Soundown Thrust Element – Old Deterioration vs. New

Soundown Vibration Dampening systems are usually found on older large yachts.  This one came out of a 123′ Feadship.  The center stud has two urethane “Coupling Thrust Elements” that have a finite life and should be checked every 10 years.  The Thrust Element in the photo was 50% deteriorated and came out in small pieces.  The picture shows the remnants on the bolt washer and in the part.  The new urethane part is also shown in the picture.

Replacing these elements is not a simple task.  The Soundown and spool combination weighs over 250 lbs which presents certain challenges when hoisting out of a bilge and carrying through a yacht’s interior.  The center bolt requires 1,150 foot pounds of torque by specification.  We must bolt the Soundown to a bench in order to apply the right torque (using a torque multiplier).  Setting up the Soundown properly and applying the right torque requires removal from the vessel and work in our machine shop.  We find it impossible to get the right set-up and leverage in the bilge or engine room.

If another yard is performing this Thrust Element change in your engine room make sure they are applying the right torque to the center bolt.  If they are – and have figured out how to do this without taking it out of the vessel – please send me a quick email.  My mechanics do not appreciate the health benefits of the workout required to haul 250 lbs out of the boat.