How to Move a Prop Shaft Back

[Erik Stelwagen]

Dear cruisers,

The seal on our Yanmar 3jh3 transmission broke and as a result it is leaking transmission fluid through the starter motor. We´re trying to remove the transmission so that we can replace the seal.

To be able to remove the transmission we need to move back our propellor shaft. Does anybody here know how to do this?

Any advice s greatly appreciated.

[familycruisers]

Are you in the water or on the hard?

[Erik Stelwagen]

We´re in the water.

[familycruisers]

Thats trickier then. What type of stuffing box?

[familycruisers]

Well, in any case that connection needs to be eased to allow it to move.

[David M]

You are much safer doing this on the hard. I'm sure you can imagine what will happen if things go wrong.

Good boatyards have knowledgeable people who can give you advice on how to fix the problem for your particular boat.

[familycruisers]

I agree

[Charlie]

I just did this on my boat but all I had to do was push the shaft back while turning it back and forth. Till it was stopped by the zincs I then had to remove those so that I could move it back further. I forgot to say I have a traditional stuffing box. YMMV it depends on how much room there is behind the propeller.

[bobconnie]

AHH If you can get a 1/2 in clearence between the two halfs of the coupler, you can loosen the front motor mounts and take back mounts loose, raise rear of motor and trans, remove and fix ! Its worked for me in the past ! just a thought Bob and Connie

[familycruisers]

I guess it comes down to what YOU are comfortable doing.

[ovrmyhead]

I haven't tried it but know an old salt that would change his packing in the water. He'd stuff the holes around his cutlass with plastic bags to slow the flow. Been thinking about trying it myself but not sure if I have the nerve.

[senormechanico]

I replaced the original bellows on my PSS shaft seal after about ten years.
Did it in the water, took a deep breath, gasped at the water inflow, but went ahead anyway. In reality, it wasn't bad at all.
Did that in a Lord Nelson 35 standing on my head leaning over the engine.