Yanmar SD50 Saildrives - Have the Cone Clutch Problems Been Solved ?

[colemj]

Originally Posted by katsumi

I am sure I read somewhere about Volvo having the same problem and it was eliminated by changing the oil to motor oil, has anyone else heard or tried this?

The Volvos were disc clutches and the ATF was causing burning of the discs from slipping. Different beast and problem than the Yanmar cones.

Mark

[riskyray]

Well looks like I am a sucker again. I just replaced my SD 40 with the 50 a couple of years ago. I do use the recommended clutch oil Merc lube Plus. Replaced the starboard clutch at 300 hours and 800 hours. Replaced the Port at 1275 hours. So Pissed off I went to Yanmar mechanic trying to figure our what other brand I can use. Turns out that the SD 50 have had so many problems they have been taken off the market. Maybe we can get some class action suit against Yanmar? Looks like I am not the only one with this very poor design. RS

[Captain Bill]

Originally Posted by colemj

The Volvos were disc clutches and the ATF was causing burning of the discs from slipping. Different beast and problem than the Yanmar cones.

Mark

Of course now the SD60's have disk clutches. One has to wonder if they have just replaced one problem with another. It makes no sense to me that they just didn't go back to dog clutches. I guess it's an engineer problem.

[colemj]

For some reason, I seem to recall being told that dog clutches were only usable on lower HP engines. Yanmar did use the dog clutches (SD20) on <30hp engines, but cone clutches (SD40/50) on higher ones.

Volvo used cone clutches on all of their drives until the relatively recent change to disc clutches. The early problem of burning the clutches was solved by changing the type of lubrication fluid used. Since then, I haven't heard of any Volvo disc clutch problems, so hopefully the same will be true for Yanmar.

Honestly, though, I cannot understand why Volvo has such a good track record with saildrives and Yanmar has such a poor one (the SD20 excluded, of course). When you look at the schematics and parts, they pretty much look exactly the same. I believe they are both built by the same company (ZF).

However, one is hard pressed to find accounts of bad Volvo cone clutches, while one cannot find ANY account of a Yanmar cone clutch that has served a reasonable life. Yanmar publishes maintenance requirements in their manual of pulling and lapping the cones every 500hrs, while Volvo doesn't mention their clutch, or service of, at all in their service manual.

Yet, you put the schematics of both on top of each other and they almost match completely.

Mark

[arsenelupiga]

i have sd 50 and engineering problems appear intentional to me to generate revenue. no point worrying.

new world of capitalism

the only solution is to get on top of things yourself.

[peterp]

Like Kasumi I would be most interested to hear from contributors to this thread at what engine hours one might expect to have these cone problems discussed with the SD50 saildrive, mine are (touch wood) working perfectly about 230 hours on both. Regards Peter

[capbillh]

I just bought a new Jeanneau with the Yanmar 3JH5CE. Hopefully it is coming with the SD-60 model since official Yanmar posted a tech notice that the SD-60 replaces the SD-50. The lower unit has "ZF" with the number 3321401010 cast into the upper section. Attached is the notice.(I tried).

[capbillh]

YMTQTB13-022-Notice-of-replacement-SD60. search the web for it
21 August 2013

[Captain Bill]

Originally Posted by peterp

Like Kasumi I would be most interested to hear from contributors to this thread at what engine hours one might expect to have these cone problems discussed with the SD50 saildrive, mine are (touch wood) working perfectly about 230 hours on both. Regards Peter

It would appear to be at least somewhat related to whether you are using right or left handed props. I got nearly 3000 hours on mine before having problems with reverse with left hand props. People with right hand props have trouble more often and earlier and in forward gear(note that left hand gear reverse uses the same clutch face as right hand forward). You are already past the lower hours I have seen reported for right hand props. Of course we probably don't hear from people complaining about about going thousands of hours without problems.

[Garrettw]

Originally Posted by capbillh

I just bought a new Jeanneau with the Yanmar 3JH5CE. Hopefully it is coming with the SD-60 model since official Yanmar posted a tech notice that the SD-60 replaces the SD-50. The lower unit has "ZF" with the number 3321401010 cast into the upper section. Attached is the notice.(I tried).

New Jeanneaus have been coming with the SD60 since maybe Q2 of 2014 so as long as your boat was built past that you should get one.


Sent from my iPad using Cruisers Sailing Forum

[capbillh]

Garrettw, thanks. i went down to Marion Dec 4th to see and take pics but it was just 2 days out of the tank for wet testing. It was ordered by the dealer on spec at the boat show">Annapolis Boat Show. The build date is probably about the beginning of November. It will be shipped up about the 19th of this month.

[sowwaninii]

Originally Posted by Sunnygirl

Cheers Mark, I agree, it seems that the cones will run up into the 1000's of hours and maybe never lose grip. I'f anything excasserbates glazing the failure will happen sooner. e.g. I got a rope wrapped on a prop, 6 months later that system needed lapping. Heavy props, fast gear changes etc will reduce the re-lapping interval. I was taught to use rudder thrust to bring my cat sideways into a berth by rapid reverse / forward cycling on both engines, probably wouldn't be a great life extender. Consider also the Gori folding prop chshions, some people chew them up fast and others don't. My guess is that if you clunk those out fast you'll also need to re-lap your cones faster too. Same way some people burn out clutch plates faster than others in manual cars or trucks.

Have a SD50 with under 350 hours and had same experience. Rope wrap and 1 month later had leak from bell housing and problems getting into gear. Saildrive pulled and cone clutch glazed!

[matauri500]

I note that you said that "sail drive pulled". Are you aware that the clutch can be removed for lapping without pulling the sail drive. All the necessary clutch work for lapping can be done with the boat in the water from inside the engine compartment.
Doug
Matauri500

[sowwaninii]

Doug-
Appreciate your quick response. Unfortunately, had transmission fluid leaking from bell housing and only way to access seal and replace was by pulling saildrive. This leak began immediately following line entanglement, so hard for me to believe not related. Any thoughts?

[Captain Bill]

Originally Posted by sowwaninii

Doug-
Appreciate your quick response. Unfortunately, had transmission fluid leaking from bell housing and only way to access seal and replace was by pulling saildrive. This leak began immediately following line entanglement, so hard for me to believe not related. Any thoughts?

rives

If the clutch was slipping enough to glaze the drive probably got extremely hot. Since these drives are sealed units more heat means more pressure and the seals are the weak links and will fail. I once had a small amount of water in the oil of one of my drives and during a high speed run to make a bridge the oil reached the boiling point of water and the water flashed to steam. The pressure actually inverted the oil seal and blew all of the oil out of the drive through the bell housing. 1.8 liters of 90W makes one hell of a smelly mess. The drive then proceeded to fill with sea water through the failed prop shaft seal. My choice rebuild the drive or wait 3 months for a new one. By the time all was said and done it was a $5000+ lesson. If you ever find a trace of water in your fluid don't use the drive at high speed and get it fixed asap.

I have had to replace my upper main seals twice on other occasions, but fortunately my engine room layout allows me to slide my engine forward about 10 inches and I am able to change these seals without hauling the boat and removing the drive.