Tuesday, 7 August 2012

Propeller Shaft Tube: The Final Chapter


It sounded so simple.  Now that I’ve changed the propeller shaft tube and re-stratified the hull, all you guys have to do is check the alignment with the gear box, tighten all the screws and change the rubber stuffing box.”  The friend-of-a-friend who helped us with the propeller shaft tube drama left us with these cheery words of encouragement.  But we knew better (at least I did; as I’ve mentioned before, Patrick is hopelessly optimistic*).   
(*optimistic and lucky !  See Addendum to Tubed)

Of course, the shaft was not perfectly aligned with the gear box, and if the tube is already stratified in place and thus not moveable, the only other solution is to move the motor.  When the mechanic told us this, I thought it was a joke and let out a hardy belly-laugh to play along, which was promptly met with blanks stares. 

I was envisaging a huge crane with chains and winches to lift the motor off the chassis to reposition it.  In fact, all that was really needed was a small fine-tuning of the position, which is accomplished by adjusting 4 x 4 sets of screws on the engine mounts (silent blocks).  We were also told that a crow bar might be handy.  Not having a crow bar, we can report that the center support from an old beechwood IKEA table works well, too.    

The 2 "easy-to-reach" engine mounts (red circles).
Guru Bob came over to help with this task, which involved painstakingly loosening and tightening sets of screws that were both rusted and, for 2 out of 4, nearly impossible to reach.  After more than 3 hours of tweeking and several good shoves with the IKEA lever, we got something that looked pretty good.

The mechanic came over to inspect it the next morning and confirmed that it was pretty good.  But not good enough.  We were reduced to measuring the gap differences between the gear box and the intruding propeller shaft with one of those little red straws that comes with a can of WD-40.  With this fine gauged instrument, we could see that indeed there was more space on the top than the bottom.  Back to tweeking.

Patrick and I tackled it alone this time, which meant that after 2 hours of going around in circles (it's better, it's worse, it's better, it's worse), I threw down my WD-40 straw and said, “This is madness !  Let’s just PAY SOMEBODY to do this !  We’re never going to get it aligned !” to which my better half suggested that I take a little break and go work on something else.  Another hour later, he called me to come check his work, and it was nearly perfect.  We spent another few minutes fine tuning the fine tuning and decided that it just wasn’t going to get any better.  The next day, the mechanic verified our work and this time said “Not bad at all !

Greasing the rubber stuffing box (Volvo Joint).
Patrick asked how long it takes a pro to do one of these alignments.  Our mechanic said it typically takes about 3 hours if all goes well, but he said he has taken up to 2 full days to get it right sometimes.  He gave us the green light and we tightened all the screws and connected the new rubber stuffing box.  We had anticipated having to call in for help on that task since it’s a rather important piece (the thing that keeps water from gushing into your boat through the shaft tube).  But at that point, we were so battle-worn that we just decided to do the damn thing ourselves.  We had instructions (with pictures !) and the mechanic talked us through it before hand.

And now it’s done.  The whole 2.5 month drama is finished. 

Gear box, shaft, and suffing box fixed to shaft tube: before and after.

And strangely, we don’t really feel like celebrating.  As the resident pessimist, I am waiting for the proverbial other shoe to drop, with an ever-present voice in my head saying “we’ll see, we’ll see…it’s not over yet”.  Even Patrick isn’t rushing to pop the champagne cork.  It’s hard to feel victorious when we’ve got so many other jobs ahead of us and summer is wasting away (if you dare to call 6 days without rain in 2 months “summer”).  But never fear, a big bubbly gin and tonic will mark a healthy and well-deserved pause and we’ll celebrate when we’re on the water enjoying the fruits of our labour.

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