With what we believe to be the biggest critical job out of the way "holes in the poop tank!" , it was time to face the next job.

Since we've owned Flirtie, selecting forward, neutral and reverse gear on the starboard engine has never been a smooth operation. With the port engine always there as reference the difference was always noticeable. During last season it was becoming worse and we were fearful that without some love and attention there was a good chance it was going to fail us at a critical moment like coming into a marina or approaching a dock.

Unfortunately the setup on Flirtie is more complex than on a lot of boats because we have two engines and dual controls - above and below deck. This means there are significantly more control cables and complexity. By way of example on a typical yacht of similar length you would have a single throttle cable and single gearbox cable. On Flirtie we have 4 throttle cables and 6 gearbox cables and a couple of mechanical transfer boxes. These mechanical transfer boxes are controlled by yet another cable.

Previously we have checked, adjusted and greased the transfer boxes, checked the cables themselves so we knew the problem was associated with the actual gearbox gear shift mechanism.

To better understand the problem we started the exercise by downloading the workshop manual Volvo Penta MS2 Workshop Manual

The workshop manual is pretty detailed and there is a section specifically dealing with the gear shift mechanism.

Taking the mechanism apart looked pretty straight forward on paper but it was apparent that we would need a few parts for the reassembly like washers, seals etc. In the end we decided to order the following parts before we drained the gearbox oil and started the disassembly.

Marinepartseurope

1) 40, Sealing Ring, 958838
2) 36, O-Ring, 925065
3) 37, Spring, 814184
4) 41, Clevis Pin, 942871
5) 42, Spring Pin, 951924

We were keeping our fingers crossed that with a good clean and the new parts we'd be back up and running but we really wouldn't know until we got everything out and we could inspect everything closely.


complete shift mechanism


complete shift mechanism


disassembled shift mechanism


bearing housing


close-up of the bearing housing showing wear


close-up of the bearing housing showing wear

Everything looked fine with the exception of the bearing housing. Putting money aside we would like to replace the bearing housing but we were also pretty confident that if we ground away the ridges we could get the mechanism to work reliably albeit not necessarily as smooth as a new one.

Being careful with a needle file set from amazon and finally emery paper and oil we set to work to remove the ridges and polish the surface.

With everything reassembled and the gearbox filled with oil it was the moment of truth!!!

Success!!!

We must confess it still isn't quite as smooth as the port gearbox selection, but it's certainly a vast improvement and we're now confident it won't let us down.



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