Westerbeke / Hurth Grinding

[LIsailor]

On my new to me 1985 Sabre 36, I have what I believe to me a Westerbeke W27A with a Hurth transmission. I am having trouble determining the model of either.

Here's the long story short, she was motored a good distance to where I purchased her. I had a survey done but I skipped the sea trial as I determined it would not give me any additional info I needed. Rig is old. Instruments are old. etc.
Knowing she was just motored around I took a gamble. For the sea trial there was the additional fee plus the yard fee to launch which in total was over $600. Money I could put towards any issues so...

The motor starts great and runs smooth. When I was winterizing the motor, I decided to put it into gear. Both forward and reverse grind and do not engage. I did not push or force it and decided to look at it in the spring which I am starting to do now.
By hand on the transmission shifter itself, I can put it into forward and reverse with ease (Motor not running)

I am planning to spend the coming weekend working on the motor/trans. Any ideas? Things I should start with?

Thanks.

[skipmac]

Have you tried to shift from the controller and then looking at the transmission to see if the lever on the transmission is moving far enough? Could be that the shift linkage is not pushing the lever on the transmission all the way into gear which could cause grinding as the gears could be partly engaged.

[S/V Antares]

The W27 was usually mated to a Hurth/ZF 10 . This is a "dog clutch" type mechanical gear that typicaly works or has isues getting into gear. You need to identify your gear. Grinding sounds like a drive plate issue which is a plate between the engine and trhe trans.

A picture or part number would help us help you.

[Sailmonkey]

A zf hurth trans cannot make a grinding noise as the only way to go into or out of gear is through clutch discs. If you hear a grinding I suggest checking the damper plate.

[LIsailor]

Shift linkage and damper plate. I was thinking the same and am happy to hear you all think so as well confirming my suspicions.
Thanks. I will let you know my findings.

[LIsailor]

The motor is a W27. Here are some pics of the transmission. It does say Germany and made in Italy so I think that means it is a ZF? I can't find a model number or cannot see it at least. Can you identify?

[S/V Antares]

That looks like a ZF10 . My W27 came with one. The W27 has a a spring type damper plate. It is not hard to take the trans and adapter plate off to check the damperplate. Looks like you have had some leaking from the rear mounted heat exchanger just above the belhousing.

[LIsailor]

Yes. I noticed that. On the list. Lol. Thx

[LIsailor]

Ok. So now I have changed the transmission fluid. I can shift into forward and reverse with what seems to me to be positive engagement. With the motor running it is the same and the shaft is spinning in both forward an reverse so it is going into gear.
Only when in forward and reverse (not neutral) a get a rubbing, clanking sort of sound. Not really a grinding noise. It almost seems like the damper plate but I have read that it will make noise even in neutral when that is the case. Could it still be something on the transmission?

[S/V Antares]

LI, Does it go away if you raise the rpm a little?

Remember diesels do not turn smoothly ...they "Ratchet" especially at low rpm. A worn damper will make much more noise at low rpm even more if it is gear because there is more mass turning.

The ZF takes ATF. and not much. Open the fill (17mm where you put the oil in) and use a long stick magnet to see if there is any metal shavings at the bottom.

[Jbaffoh]

I recently had the same clanking/crunching issue with my Perkins M30/Hurth 50. In gear at low RPM's it sounded like something had broken and was being tortured in the transmission. Or, maybe the cutlass bearing. Or maybe a loose shaft anode demolishing the strut. Definitely not the damper plate, because it only happened in gear. But at full speed, everything sounded fine.

After draining the ATF, I found gold glittery particles suspended, and some grayish flakes at the bottom. A Hurth specialist anticipated what I saw and told me over the phone that the contents were normal.

Then, he said a poorly running motor can make it sound like the transmission is eating itself. I was skeptical.

He told me to loosen my injector nipples one by one and see if it makes a difference. Turns out one of three cylinders was not firing, so I had the injectors tested. One was not functioning, and two were really bad.

$126 later, I had three rebuilt injectors, a perfectly running motor, and no more crunching/banging down under.

Hope that helps. Good luck!

[LIsailor]

Good news. Upon further investigation, it was the cutlass bearing. It's always amazing how much sounds resonate through a boat.
Unfortunately, due to the poor maintenance schedule the PO held the bronze shaft had scored enough to create a quite shoulder and a resulting decent amount of play. On the list now is a new stainless shaft, cutlass bearing, and stuffing box assembly while I'm at it.
At least it's not the transmission.
Thanks all!