We never know the percentage failure rate in these pages, we can only respond to our personal experience and that of other posts. The SD60 may be more reliable than the SD50, but only time will tell.
A big worry for the SD60 is the difficulty of the repairs
, and the reported short life before the next failure. The engine
needs to be disconnected and moved forward, the top half of the gearbox
is dismantled so the clutch shaft can be removed. Then re-connection of the engine
is very tricky.
In my case the clutches started slipping 5 weeks after the first repair, and there have been other similar reports. Yanmar don't seem to know what is causing the problem, or how to fix it, and we are now waiting on "improved" parts
The Greek Yanmar agent says the SD50 is a better gearbox
, and I agree with him. The SD50 has known problems, and known solutions, including Panache's excellent thrust bearing kit. Also it is much easier to replace or service
the clutch assembly. He is reporting 'many' SD60 failures, but who knows what the actual numbers are.
So, I would not recommend changing from a SD50 to a SD60. I am thinking of going the other way!