Lost prop from sail drive

[Boaterbob]

Running low load in reverse at 1200 RPM my D55 Volvo sail drive prop spun off into the mud under the boat at dock. Diver picked it up and the rubber mounting hub was out of the propeller center. It is too big to push back in. Three bladed fixed prop is in good shape. Retainer screw is missing, which caused the problem. Anyone have experience fixing this? Do I need a special press to reinstall the hard rubber hub? How did the prop come off the hub? Why did not the entire assembly go off with the hub in place? Relatively easy fix but unsettling. Next time I will really tighten the retaining screw. Boat is 2004 Bavaria 41.

[Captain Bill]

Most props can be re-hubbed by any good prop shop. This usually means replacing the rubber shock core which is a friction fit and is usually damaged by the process of coming off. I have seen this happen a couple of time when a line gets tangled in the prop while operating in reverse and the hub rubber has or is close to failure. When put in reverse the line stops the prop from turning or at least causes th prop to slip on the hub and the pressure of the prop on the shaft nut in reverse is enough to unscrew the prop nut if the locking screw is not in place. Use a little loctite or other thread locking compound on that retaining screw.

[DougR]

Normally when you install the prop the sequence is : thrust sleeve on the shaft goes on first, then the prop, then a large plastic washer, then the cone, then the lock screw. The thrust sleeve absorbs the prop thrust in forward. The plastic washer prevents the prop from grinding against the cone in reverse, possibly loosening or damaging the cone.

If the rubber cushion inside the prop hub has spun (slipped) then it's not a good idea to try to reuse the hub. It's better to have a new hub assembly pressed into the prop, and a decent prop shop can do this. It takes a healthy hydraulic press to do the job.

Typically the locking screw is a one time use item, and it's important to torque the cone and lock screw to the specified torque.

DougR