Greetings-Here''s a question I would love to have answered. The background first: Perkins M30 28hp 3 cyl Perama engine. Hurth 50 (now ZF) gearbox. With about 690 hrs on the engine and transmission, we had an unnoticed leak around the
hatch in the ####### sole. It slowly dripped salt water on one of the rear motor mounts and keyhole plate holding on the transmission. The ear joining the motor mount to the engine cracked, and the engine got shook around on three mounts. This in turn wore out the output
shaft seal, resulting in a loss of fluid. We heard unfriendly noises coming from the gear box while underway, stopped, saw the lack of fluid and replaced it, and went on our merry way home. With the replacement of the fluid the tranny performed flawlessly all the way home. At home I removed the transmission thinking I could replace the out put
shaft seal and be happy again. In pulling it, the splines on the shaft to the engine, as well as the damper plate teeth were badly chewed up. In reassessing the situation, I opted for a new transmission vs a rebuild of this one. I got the next bigger size, a ZF-10(formerly known as a Hurth 100). I replaced the rear motor mounts, damper plate, mounting plate, cutlass bearing, and installed the new transmission. The engine was realigned to within 2/1000, and has always had a rubber donut joining the couplings. The
propellor is three years old and doesn''t seem to be out of whack. After 8 hours or so of operation the new transmission began to slip. It was intermittent initially, maybe every 8 hrs or so. At 80 hours of use the transmission really acted badly. The ZF folks were contacted, and initially thought heat was the culprit doing in the new transmission. Then it was believed that vibration caused the early demise. They put all new parts in the transmission, and now it performs as it should. I added a water cooler to the side of the tranny for piece of mind about the heat issue. Upon reinstallation though, there are some slight signs of the same wear on the spindles that go into the damper plate. The engine has always been in alignment with this transmission within 2/1000, as it is now. The engine now has 781 hours. What would cause the wear on the spindles and damper plate? We don''t idle much as we were at the dock on shore power, or when cruising have two solars and a wind generator to help top up the batteries. The valves are quiet according to those who have heard the engine(I''ve never heard loud valves to know better). I attributed the original tranny''s teeth being chewed up to misalignment, the broken motor mount, or maybe high speed shifting by the previous owner during the first couple hundred hours of life. The new one though has always been pampered, aligned, low speed shifting, anal retentive attention to maintenance. Any ideas? The engine purrs like a kitten, as it should with low hours. I''m not looking for something wrong with the engine, but would like to head off trouble at the pass if necessary or possible.
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