Three weeks ago we returned from an 11 day cruise on which we put 40 hours on our MD22L w/120SE saildrive. We check fluids at each start and were happy that the engine with 2100 hrs worked without issue. Since then we have done three sails and two overnights with no issues...until Saturday.
From anchor saturday am, we checked fluids and didnt have to look far for trouble. I opened the engine access door and saw transmission fluid pooled on the saildrive gasket.
Hope it wasn't transmission fluid! The 120S-E requires hypoid gear oil (API GL-5 SAE 75W-90), not transmission fluid (ATF). If it was truly transmission fluid, that could be part of the problem (incorrectly filled at last oil change).
I opened the saildrive dipstick and it let out a hiss. The fluid was frothy white. I then unspun the black fluid fill cap on the top of the saildrive and found two or three deformed washers jammed way up inside the black cap, the cap deformed by apparent high heat and froth.
1) Is high heat is common in the saildrive transmission?
No, ours (same engine/saildrive combination, MD22L-B and Saildrive 120S-E) is normally barely warm to the touch, it's cooled by the lower leg being immersed in the sea and the oil is circulated inside.
2)did water enter at shaft seal?
Most likely. There is a remote chance the housing took damage, either mechanical or electrolysis, which will be obvious on haulout. There's an even more remote chance that the inner channels for oil/water have been breached, but that's very unlikely. There is a slim chance that the diaphragm change was done incorrectly and water seeped in along the gasket where the lower and upper housing are joined, but again this is unlikely.
3) Is it common to change shaft seals when one changes saildrive gasket?
Yes, or at the very least to inspect them. The shaft must also be inspected, as wear often occurs on the shaft, in which case even with new seals it will no longer seal well.
4)how did washers get thrust so far into the melted cap?
Not sure. It looks like the vertical shaft may have been shoved upwards into the cap, which would explain the heat (friction), melted cap and shoved up washers. Upon disassembly, you will likely find broken/worn teeth at the bottom of it then. This could be caused by something hitting or blocking the propeller very suddenly, or the vertical shaft retention failing (I'm not sure how it is retained exactly, but I believe it is removed upwards).
5)how much will it cost to get it rebuilt?
Don't know, I usually do my own work as I've seen too much shockingly poor work by "professionals". Good ones are hard to find and rarely cheap.
6)does engine need to be pulled to get saildrive out?
The engine only needs to move about 10cm forwards, for which on our 40 Ocean there is enough room to slide on the bearers without falling off. The rear needs to be supported from underneath to prevent the rear falling down into the engine sump when the saildrive is removed. A sturdy plank and some wedges did it for me.
7)How much is a new saildrive?
Around £5000 plus tax and labour last I checked. Probably more now, as the £ is in the toilet. Additionally, the gear ratio is different on newer models (which the replacement will likely be), so you will also need a different propeller.
8)Does anyone stock rebuilt saildrive ready to swap the core?
I've seen one or two on eBay over the years, but you'd have to get very lucky.
9)if one were to open a normal 120SE top cap, what should it look like (photo please!)?
Haven't got a photo, but probably can take one in a while.
Good luck with this! I think the story can either be that water got in through the usual routed (failed lip seals/shaft wear) and caused this, although from reports I've heard, people have done many miles with a water/oil emulsion and reported little follow-up damage (water is a pretty good lubricant). Or that you've hit something that stopped the propeller so hard that the gear teeth were pushed apart and the shaft moved upwards. There should be plenty of evidence of this once the boat is hauled out and the propeller shaft removed. In that case, you should be able to make an insurance claim. If it was due to poor servicing (you mentioned a recent diaphragm change), you best get a lawyer.
