Caught a line around prop: Did I damage my reversing gear?

[ernst]

Yesterday it happened: a dockline went overboard and wrapped itself around the shaft. Of course it was my fault (single-handing, no one else to blame). Fortunately, I was in the marina (I was just moving the boat from my summer slip to a more protected slip for the winter) and, given that this is December, there were not many boats to bump into. I managed to lasso a piling to keep stationary and the marina's tug then pulled me into the winter slip.

Symptoms: I was applying a good dose of reverse (20 knot winds in a narrow fairway!) and the motor stalled immediately. With a very audible snap, the line wrapped itself tightly around shaft (or prop), the other end tight on a cleat on deck. I could start the motor but it died immediately when I put it in reverse. What was more frightening to me was that in forward, the motor would turn but the shaft not!! (I checked under the V-drive).

It was with a lot of trepidation that I opened the reversing gear today, expecting some horrible carnage. Visually, things looked fine (no shredded cogs etc). I decided to turn the motor with the starter (the button I had installed this summer in the engine room really paid off!). The starter turned the motor which turned the shaft in the center (don't know how it is called) but the big round thing around which the reversing band goes did not turn in either forward nor reverse.

Then the amazing thing happened: I was wiggling the line, pulling on it, playing with the starter etc -- and something moved! To make a long story short, the shaft started to turn and I was able to pull the line off! (It suffered surprisingly little damage and I think it will do further duty as a spare dockline).

Everything seems to be fine: I can power forward and backward, the shaft turns, the boat is being propelled (at least in the slip). I did not go out (temps were about 32F, wind 25 gusting to 35...) but, as far as I can tell, everything is OK.

So, here is my question: is there a possibility that I did any damage to any parts? If yes, how can I test it?

Thanks!

--Ernst

[hanleyclifford]

If you can run the engine up to cruising rpm in gear tied to the dock with no vibration and no visible wobble of the drive shaft you have probably dodged the proverbial bullet. Best wishes for exactly that, Hanley

[jhwelch]

Over the course of years of cruising in Maine I have caught onto various semi-submerged lines which stopped the engine suddenly.

At some point the key and keyway on the output shaft of the reversing gear became damaged and I had to replace the reversing gear. It was pretty amazing that it operated in the condition I found it.

So worse case I imagine you could have sheared one of the two keys in the drive shaft system but you seem to have escaped that issue.

I had a new shaft made recently and it came with a pretty stubby key and keyway. I had the boatyard make it longer, almost double the size of the original one, on the theory that this would be stronger in case of a sudden stoppage.

-Jonathan

[ArtJ]

You may want to consider going back to the original size keys and keep spares aboard
instead. It is better to shear a key than damage the engine or drive train.

Regards,

Art

[msmith10]

Agree with above. I suspect that immediately after your incident, in reverse the motor would stall out, but in forward, the clutch was slipping.

[sastanley]

ernst. I would do a full alignment check to further check the condition Hanley mentioned above...this will confirm or deny any 'issues' (like a bent shaft or damaged key. etc..)
Now, how the heck you check alignment on a V-drive, I have no idea!

[edwardc]

...Now, how the heck you check alignment on a V-drive, I have no idea!

I want to know too, because I've got to realign my rebuilt engine that's going back into the boat tomorrow!

[ernst]

Agree with above. I suspect that immediately after your incident, in reverse the motor would stall out, but in forward, the clutch was slipping.

Yes, that is my interpretation of the events, too (at least in retrospect; as I said, I was expecting to find a bowl of cog salad under the cover!).

So I suppose the slipping clutch has protected the machinery?

[ernst]

ernst. I would do a full alignment check to further check the condition Hanley mentioned above...this will confirm or deny any 'issues' (like a bent shaft or damaged key. etc..)
Now, how the heck you check alignment on a V-drive, I have no idea!

Good idea! I will do that next time there is a reasonable day (yesterday I was still busy tying off the boat for winter, winterizing all systems, changing the oil etc.

Oh, and checking the alignment is actually easier on a V-drive than on a straight shaft. At least I believe it is (this boat being the only one where I have ever done an alignment so I cannot compare directly) , because the coupling is FORWARD of the motor, rather than BEHIND it. You remove the companionway steps and voila, there is the coupling right in front of you. There is not a whole lotta space under the V-drive but it is perfectly adequate. I have done it a few times.