Sheared Volvo Penta saildrive prop hub removal

[paullo]

Hi,

Hoping to get some advice on here. As title, I have a 120S saildrive and lost all drive suddenly. It looks like the prob hub has had the splines sheared off so it is now just spinning around the driveshaft. (The hub has always had a lot of play in it since I bought the boat, guessing it finally gave in). I'm stumped on how to remove the damaged prop hub. Normally I use the hub which should grip the drive shaft, lock the hub with a block of wood and get the bolts off but obviously can't do that in it's current condition.

Does anyone have any ideas before I bring out the angle grinder, hammer and lots of swearing?

Thanks in advance

[Fore and Aft]

Paullo can't you just put the motor in gear? Make sure you check the shaft spline for cracks? I have seen a similar situation before and the shaft had cracked from all the vibration.
Cheers

[paullo]

Putting it in gear adds a fair bit of friction but not enough to stop the drive shaft turning. Is that normal or should having it in gear basically lock the drive shaft completely?

[Fore and Aft]

Paullo it might be time to get a mechanic involved. It is a fairly common issue so they should know how to do it. Could you have the engine in gear and wedge the propeller with a timber prop so it is at least creating some friction on the shaft?
Cheers

[paullo]

Wedging the prop wont make any difference because the prop hub is basically disconnected from the drive shaft so the drive shaft will just spin regardless of wedging. Angle grinder, hammer and swearing it is

[skipperpete]

You don’t mention what propeller is fitted to your saildrive so I’ll assume its not a Gori , Maxprop or other folding or feathering prop. I’ve never ever seen a saildrive propeller strip the spline on the propshaft or the hub but seen a lot that have spun the rubber element in the prop hub. If the rubber element is still firmly attached to the shaft hub and the propeller itself has spun on the rubber donut try drilling a couple of holes through the prop and screw a couple of self tapping screws through the alloy shell and into the rubber bushing, they should stop the slippage enough to undo the hub nut. On a yanmar saildrive this works sometimes (but not if the bushing is slipping on the shaft hub) so I made up a couple of special allen keys to take off the anode and then the two retaining bolts on the carrier ….. then you can remove the entire carrier assembly and hold it in a way that enables removal of the nut…. Or makes it easier to split off the propeller with your angle grinder if all else fails.

[paullo]

It's the very simple 2 blade folding prop. tbh when I first bought the boat the guys I bought it from were super friendly and helped with the prop fitting, standing and running rigging. There was a LOT of play in the hub when first fitted and despite one of the previous owners putting 250 gorrilion n/m of torque on the bolt with a 6ft long breaker bar it still wobbled a LOT. Now a few years on I feel like that loosely fitting hub has finally gave way.

You mention a rubber element in the prop hub, there is no rubber element. This is a small 27ft cruiser. Brass prop hub is fitted onto the steel drive shaft and fitted up between the drive shaft splines and prop hub splines. Nothing complicated, should never fail

Nice idea about drilling some screws through the hub into the drive shaft though, or since the hub is so loose now sticking some shims to grab against the drive shaft and putting holes through the hub to secure shims in place could be an idea

[DougR]

Without knowing the manufacturer of the propeller it is impossible to say what is really inside the hub....solid brass or cushion hub. But, most major prop builders for saildrive applications use a rubber hub of some description.

Of course, the splines inside the hub can become worn and present a lot of slop between the shaft and the hub. Personally I have never one get to the point of failing, but I can believe it could happen. For many brands of prop, replacement cushion hubs are available to press into the brass hub.

The photos here show different hubs that were available over the years for VP saildrive props, as well as the various nuts used to hold the prop on the shaft.

My guess is that you will need to use an impact wrench to spin the nut off the shaft as there’s isnt any other way to keep the shaft from turning.

[Antares]

Try an impact wrench. Even if the shaft can not be locked, it should do the job. Don't be overly concerned about the impacts as there may not be other alternatives. With a straight spline, excessive tightening torque doesn't really accomplish much.

[paullo]

For anyone else with the same problem the solution turned out to be embarrasingly simple. Stick it in gear, one person on the outside to remove the bolts and another inside to use a large spanner and lock the crank shaft in place. Thanks all