Why Would My Inboard Ski Boat Shaft Be Squeaking?

A misaligned drive shaft can result in a squeaking noise from your boat.

Inboard ski boats have a drive shaft that runs through the hull of the boat and into the water, where it is attached to a propeller. The shaft can squeak if its seal is too tight.

Stuffing Box

The stuffing box is where the drive shaft goes through the hull of the boat. There are a few strips of waxed rope wrapped around the shaft that slow the flow of water into the hull to a trickle. This should not be completely sealed, as that would deteriorate the rope from too much friction.

Alignment

The prop shaft must be properly aligned for smooth operation. A misaligned shaft will put more pressure against one area of the stuffing box than the others, and this excess pressure can cause a squeaking noise when it spins.

Foreign Objects

The cause of shaft squealing may not necessarily be caused by the shaft itself. If you have unknowingly run over a rope, it may have become entangled in the shaft between the propeller and the hull. This can cause vibrations or other noises, and it should be carefully untangled.

References

• Yacht Survey: Drive System Alignment