propeller shaft question

[Tim Lee]

I am replacing a leaking volvo stern seal. I am planning to do this next weekend dried out between tides. I was going to pop down to the boat this weekend to make sure I can loosen off the prop shaft from the coupling. This seems to be the most likely part of the exercise to cause excessive use of expletives!
However, it has just occurred to me that I have a rope stripper. It is this type -

http://www.ropestripper.com/strippers.php

- the one advertised by the bare chested female in the comics!

I bought the boat with this already fitted and what I can't quite work out now (and can't visually check with the boat still in the water) is whether the two faces of the stripper mechanism will just come apart when I drop the prop shaft back or whether they are held together somehow.
Obviously I want to avoid forcing the prop shaft off and damaging the rope cutter in the process.
Any help greatly appreciated.

 

[GrahamM376]

When you drop the shaft back, the stripper will slide out of the V bracket and move with the shaft. No need to dismantle it unless the bearings are worn.

 

[MoodySabre]

If the Stripper is between the P bracket and the prop (which is usual) then you won't have to take it off. Just push the shaft back far enough to get the Volvo seal off the end - clean up the shaft so as not to wreck the new one. Oh and check that there is no wear on the shaft at the point where the seal rests - if so then this could be the reason for your leak.

The Stripper comes in half - once the bolts are taken out each ring is made up of two halves that key together. A service kit is available with new nylon bearings, new springs and new bolts. Worth doing whilst you have it in bits. They give you new bolts cos the old ones get knackered whilst undoing them - mine had to be drilled off. Hopefully you needn't touch it.

 

[prv]

The two halves of the stripper don't come apart, they stay where they are on the shaft and slide back together. The fixed half has a "tooth" that engages with a bracket mounted on the boat - you will need to make sure this re-engages when you slide the shaft forwards again. Either be very careful not to rotate the shaft during the job, or if you can get at the outside it's possible to partly dismantle and put things back into place once the work inside is complete. We've had success with both techniques.

Pete

 

[Tranona]

The fitting instructions are on the website. worth taking it apart and checking bearings for wear. Put all the metal parts in a pot of kettle cleaner and they will come out like new.

Make sure you have enough clearance behind the prop to slide the shaft back far enough to remove the seal.

 

[Tim Lee]

thanks very much for your helpful answers and advice

 

[Martin_J]

Your profile does not say where you are.. I have an Ambassador stripper in my hands at the moment and you would be welcome to take a look at how it comes apart.. so you're more aware about what you will see next weekend.

As PRV says.. best not to shift the shaft backwards whilst still in the water this weekend since the tooth in the fixed part will possibly not fall back into the correct place again.. okay if you're not going to motor anywhere next week but not a good idea otherwise.

Remember - the small plastic (red, I think) sleeve that comes with the new seal.. make sure you use it (as per the instructions) to protect the new seal when sliding into place.

 

[prv]

As PRV says.. best not to shift the shaft backwards whilst still in the water this weekend since the tooth in the fixed part will possibly not fall back into the correct place again

He's presumably going to be dried out if changing a shaft seal, though, so can probably go round and sort it out.

When we found ourselves mucking about with the gearbox as described in Lustyd's list-of-faults thread, we swivelled the shaft all over the place. Sailed from Yarmouth to the Folly to Itchenor over the next couple of days, using the engine each end as normal, then to Bembridge where we dried out on the beach. I dismantled part of the cutter and put the tooth back where it should be, didn't take long. Hadn't noticed any problem from the cutter being misplaced, though not good long-term.

A week or two later my dad decided to inspect the nut again, so split the coupling and slid the shaft back. This time he was careful not to turn it, and assumed the lug would therefore go back into place when the shaft was pulled in. One evening later that week I put the boat on the foreshore near Southampton Sailing Club to check, and found that he was right.

So either way works.

Pete

 

[Tranona]

Your Dad was lucky. The fixed cutter actually rotates when it is free from the block as it would be as you push the shaft back. If your block is at the bottom gravity may well help it stay in the right place, but if it is on the side the blade can swing down.

 

[prv]

Your Dad was lucky. The fixed cutter actually rotates when it is free from the block as it would be as you push the shaft back. If your block is at the bottom gravity may well help it stay in the right place, but if it is on the side the blade can swing down.

Must admit I was surprised he'd managed to get it back into place - hence why I took the boat round the corner to dry out expecting to have to reposition it. Our fixed block is on the side of the cutless bearing; obviously just enough friction to hold the static part of the cutter in place.

Pete

 

[Tim Lee]

Oh and check that there is no wear on the shaft at the point where the seal rests - if so then this could be the reason for your leak.

Presumably if this was the case I could move the seal a few mm up the propeller and retighten it, provided the seal could still get enough purchase where it clamps on to the shaft?

 

[MoodySabre]

Presumably if this was the case I could move the seal a few mm up the propeller and retighten it, provided the seal could still get enough purchase where it clamps on to the shaft?

Yep.

 

[Tranona]

Presumably if this was the case I could move the seal a few mm up the propeller and retighten it, provided the seal could still get enough purchase where it clamps on to the shaft?

Wear can be either on the shaft or on the lips of the seals - or both. If the shaft is worn then perhaps you ought to consider replacing the shaft as well. If the stripper was a retrofit you may find (depending on your boat) that there is a spacer in the gearbox coupling to move the shaft back (see stripper installation instructions) so the seal might have ben bearing on two locations in its life. The only way to find out is to take the seal off.