Re: [Amel Yacht Owners] Hurth Transmissions freewheeling folding prop

James Alton


   My Maramu has a plate mounted just in front of the shift lever warning to never leave the transmission in Fwd. gear while sailing.  My boat has a fixed 20” (?) 3 blade prop which can produce a large amount of torque when sailing at higher speeds.  I am guessing that since your prop feathers(so produces little torque if any when feathered)  that it may not matter as much which gear you use but apparently due to the design the Reverse gear is stronger and therefore safer to use when locking the prop shaft.  Perhaps others can verify if this would be correct.

   I also read in Foley the these gears seem to last about 1000 hours on average.  The gear on my boat has the same paint as the engine and I don’t see any evidence of it having been replaced.  The engine now has just over 4,000 hours.  Could others comment on the life expectancy the have experienced with the Hurth gears?  My boat appears to have had an aluminum cooler for a very long time,  it may in fact have been original based on the installation.  I replaced the old cooler with a new aluminum one.  The old one was not leaking but when cleaning out the inside I found several pin holes that were only plugged with corrosion so it was overdue.  I just got an email back from Foley saying that they have discontinued selling the stainless coolers and now only sell the aluminum.  I wonder if there were corrosion concerns betwee the aluminum gear case and the stainless coolers.  I will try to find out. 


SV Sueno,  Maramu #220

On Dec 18, 2017, at 11:19 AM, 'Mike Ondra' mdondra@... [amelyachtowners] <amelyachtowners@...> wrote:

Who’d of thought there was so much to know about transmissions and their lubrication! Foley website full of interesting information. On a related topic.


Dr. Diesel Tip #101 at Foley says DO NOT put Hurth trans into forward to stop freewheeling, only reverse.

We have always put the trans in forward to stop the freewheeling and fold the Autoprop when under sail. Given Amels have a “C” drive, does Dr. Diesels Tip apply? Have to pose the question just in case there are opinions among our ranks.


Mike Ondra

Aletes SM#240

Falmouth Harbor, Antigua


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