Sheared Engine Mounts - Saildrive okay???

[Rezzy]

My Yanmar 4JH engine broke its engine mounts causing the SD50 saildrive to let in water through the lower and upper diaphragm. The core of the saildrive has moved a quarter inch sideways from its proper position.

Amazingly the drive works normally. Now hauled out awaiting repair. I know the drive is "soft mounted" to the engine but is the saildrive likely to be ruined?

Anyone with experience of this?

[skipperpete]

Theoretically the saildrive should be Ok unless it somehow actually caused the engine mounts to break either by vibration or by striking a submerged object. The saildrive is hard mounted to the engine but its input shaft is connected via a vibration damper plate.
This is one occasion where the diaphragms should both be replaced regardless of age.

[HeinSdL]

I would suggest that the engine/saildrive combination is OK but the rear support needs to be checked carefully. I have the same set up (4JH3E/SD40) and naturally am interested to hear why you think those mounts failed. Any thoughts on this?

[tkeithlu]

You sheared, as in the bolts broken cross section, four motor mounts? Given that the motor mounts are soft mounted, what did you hit, a breakwater at speed?

Look very carefully for cracks in the saildrive housing. Dye testing is cheap and helps. The drive could be working, but soon to fail.

[tkeithlu]

Rezzy, for you and anyone else who has taken a mighty whap on the machinery, here is a cheap red dye penetrant for finding hidden cracks. I became familiar with the stuff through doing annual inspections on my airplane.

https://www.amazon.com/CANTESCO-Visi...G4VEQXTGS2MMBF

I hope you find that all that energy went into breaking your engine mounts, which are cheap to replace, and not into cracks in the sail drive, engine bracket, or internal parts.