Volvo Penta 120 S sail drive prop issue

[JKFoster]

I half a Crealock 37 on the hard in Seward, Alaska. A mechanic replaced the gasket between its ring, the hull, and the engine (Volvo Penta MD 2030-D)/120 S sail drive interface as required every seven years per the manufacturer's recommendation. A different mechanic trying to finish putting everything back together cannot get the prop to seat on the shaft. The mechanic reports it is as though the shaft is too long. Does anyone have any ideas? The mechanic that took it apart has gone missing.

 

[Martin_J]

Did you by any chance have an Ambassador rope stripper on previously (and maybe it's gone missing whilst the prop was off)?

As standard, there's either a spacer or more usually a disc fish-line cutter on the shaft ahead of the prop. When fitting an Ambassador rope stripper, this spacer/cutter is removed and discarded (or put in the 'spares' box and forgotten about).

The spacer is shown in this next diagram in red.... and the fish-line cutter on the lower diagram..




Fish-line cutter in red below..

 

[JKFoster]

Thank you Martin J!

I will get your note and this blow-up to the mechanic at Seward Heavy Industrial working on getting the prop back on in Seward.

All the best.......

 

[Martin_J]

This picture from the internet shows what the line cutter really looks like (i.e. the part that gets omitted when fitting the stripper).



This is what the leg/propeller would look like with the Ambassador stripper in place..



I don't have any photos to hand showing what it looked like before I installed the Ambassador stripper.

 

[Tranona]

Just to clarify, that is a 130 drive with a split anode so not exactly the same as the earlier 120, but the principle is the same with the gap inside the propeller filled with either a spacer of a (ineffective) line cutter. If there has been a Stripper fitted then the back of the propeller will have been machined to remove a ridge so the gap between the face of the propeller and the anode will be around 10mm and the spacer will probably be missing. As you can see in the diagram there is a shoulder on the shaft at the end of the spline and the propeller boss butts up against this. It is important that the deltin washer 38A is in place on the aft face as this isolates the propeller from the locking cone and therefore the drive. The hub has a rubber bush which does the same for the propeller itself.

 

[Martin_J]

As Tranona says, most 120SD do have the single anode.

There is however a conversion kit available to enable the fitment of a split anode.

The photo was of my 120SD with the special split anode fitted...

This was the anode before fitting.. (machined with the extra hole and cutout for the Ambassador stripper).



And here is the aft face of the 120SD after I had bolted on the split anode mounting stubs..



Edit: Typo correction.

 

[Martin_J]

Oh and before the special split anode stubs were fitted, showing where that spacer or fish line cutter would normally sit.

 

[Martin_J]

Also as Tranona mentioned, the giveaway of whether or not an Ambassador stripper was fitted previously will be the smooth forward face of the prop and the two holes drilled into that forward face.

We're assuming you are refitting the same prop that came off.

 

[scottie]

It’s been known for the spacer ring to stick to the prop hub on removing the prop but dislodge giving the impression that it was never fitted in the first placeŷuun