Re: [Amel Yacht Owners] Hurth Transmissions freewheeling folding prop
Dave,toggle quoted messageShow quoted text
Thanks for this information. At least I now know that at least some of the Hurth 250 transmissions installed on Maramu’s are lasting longer than the 4,000 hours that mine has. So far my transmission seems to be working fine but the failure mode that you experienced does not sound like a pleasant to experience so maybe I will do something preemptive before long.
I have heard of others having a problem with their aluminum coolers corroding quickly as well. Without being bonded, I would think that the aluminum parts immersed in seawater would become the sacrificial items on the engine so maybe that could be part of your problem as you suspect. I am wondering however if there is more than one manufacturer of these coolers with some being made of a more corrosion resistant alloy? The original cooler on my transmission had a plate on it that in large letters had the name Hurth, Monchen, Made in West Germany. The old rusty hose clamps, hoses and the apparent age of the ID plate and mounting bolts suggests to me that this cooler had been on the transmission for a very long time. The one that I ordered as a replacement and installed this year with all new hoses was sold by “Mr Cool” 3306107001 ZF Transmission/Gear Cooler. The replacement cooler cost $165.00 USD. The Cooler being sold by Foley is much more expensive, $395.00 which comes with a quart of their special synthetic fluid. I think I will inquire and see what they say about the large cost differential. Can you tell me where you have been buying your coolers?
In part over corrosion concerns for my cooler, I have been flushing the engine with fresh water whenever the engine will sit for more than a couple of days which I think should help to reduce the corrosion some. I think that I will open the cooler at least every couple of seasons to see how much corrosion is present.
SV Sueno, #220