Through 5 transmissions, and approximately 1600 engine
hours (not all underway - i.e., battery charging
, etc), we have 'religiously' kept the trans in reverse while sailing. We even have a small 'dymo' marker notice on the Edson pedestal
which cautions about leaving the trans in 'forward' while sailing (or when anchored in strong current)..
The trans fluid was changed an all the failed transmissions with every engine oil change
at approximately 100 hr intervals!
There were no problems due to the installation
(alignment, etc.) which was verified during the 3rd failure by a Hurth
rep (from Annapolis) who installed a new trans under warrantee.
What we've determined (very difficult to actually confirm) is that the Hurth
trans is 'vastly overspec'd' inasmuch as it's simply not robust enough to handle the output of the 38HP Kubota engine, although the engine output (torque, HP, rpm
etc. do not even approach much less exceed the limits specified by Hurth for pleasure use/heavy duty use/continuous use.
Additionally, there are probably some design problems such as a less than adequate thrust washer and not terribly robust clutch
Hurth can give no explanation other than to say "There's something wrong with the installation
on your boat......."
We can beat this thread to death, but I'm moving on and enjoying my boat with a Twin Disc replacement for the Hurth!
Tom in Kinsale, VA