Excessive Wear on SD40 Yanmar Cone Clutch

[sikander]

Paulrack...

you mention flexofold on yr 130s saildrive....don't you have problems with barnicles to unfold the props...?
where i 'am barnicles are a serious issue

Volvo offers as an option three balde prop...don't you recommand these prop

price comparaison...??

have you heard on them...?

Thks

[carter 39]

my Cone clutch on SD 50 failed after 570 hrs!
My owners manual (2008) said nothing of of cone clutch service, it has since been revised to state that a periodic service every 500 hrs is necessary! I had it serviced by Yanmar Marmaris for 400 euro plus 32 for replacement oil !
This is obviously a design fault and I cannot understand how yanmar does not cover it in warranty??
Anyway all they did was lap the forward cone with grinding compound and put it back in, a total of 2 hrs work!
Next time around I am going to do it myself, but I still think it is totally ridiculous
on the part of Yanmar not to take responsibility for their design problem.

Now does anybody have a step by step description of how to take the cone assembly out of the sail drive? I could not see what they were doing as my engine room only allows one head in at a time so i missed the details!!

Marwan

[sikander]

Hi carter 39

it seems, but i can't garantee what i'm writing it is easier to replace cone clutch on sd 50 than sd 40 where you have to unlock the engine from the silent block, advance the engine forward to disconnect saildrive from engine to proceed to replacement of the cone clutch
all of this could be done in the water

costs me each time 2500us$ with labor

nevertheless sd 40 or sd 50 have these issues and this can become very dangerous once you lost yr transmission
let's imagine a case you are waiting for a bridge to open in intercoastal florida with a huge current and you loose the transmission....!!!!
Having sd 40 and sd 50 let you carry heavy risks.
it is game over for me.

[malolo55]

I'm sharing here and looking for an answer other than the "too bad, too sad" I'm getting from Yanmar - don't get me wrong, I think they make a great engine! I just hate the saildrive cone clutch not being reliable

I have a SD40 on my 55' Kernan custom sailboat - I bought this fabulous boat from the builder in "as new" condition in July 2007. The boat came with a feathering, 3 - blade, Sea Hawk SS prop. The engine and drive had only 180 hrs on them at the time of purchase. I pulled the boat and changed out the prop to a 3 - bladed Sea Hawk SS folding prop. (personally I prefer the folding prop as they are hydrodynamically more efficent, less vibration, have less drag, are less likely to pick up anything under sail and give better control of speed in reverse) Both props have rubber "shock absorbers" around the female splines as is reccommended in a recent Yanmar publication.(which we wern't told about) My first cone clutch was replaced after 520 hrs, it started slipping and "thunking" about 20 hrs prior.

I am now faced with another replacement after only 180 hrs. I had the linkage checked and it seems fine. In sort of a defense for Yanmar, my boat is used frequently, mostly day sails or trips across the San Pedro channel to Catalina. I rarely motor more than 10 or 15 minutes at a time just to get the boat out and back into the slip (ergo I shift gears more frequently per hour then someone that might motor for hours at a time).

When I spoke to the local Yanmar distributor they, not unlike Yanmar, looked to blame the problem on the prop or me. I've owned boats for 53 years and always maintained them well. Frankly, I think the saildrive is just poorly engineered, unfortunately like many things today, Yanmar is not taking any responsibility for their inherent design problem. Luckily for them, many boats sit in their slips 90+% of the time so the owners are not faced with this expense/aggravation, cronologically, very often!

What I think I have learned in reading this collection of comments re the SD40 and other Yanmar saildrives is that "banging" the engine into gear may add life to the cone clutch; I am however concerned as to what that might do to the gears and/or bearings. Mechanical things don't like shock loads.

The cone clutch repair has become part of regular maintenance that many buyers were unaware of at the time of purchase, and, it ain't cheap! I think Yanmar needs to 1. Make it clear to the new buyer what they are faced with in terms of frequency of repair and cost 2. set up a remuneration program for current owners which should include, at least, free replacement of the cone clutch itself if it lasts less than 500 hours; we owners are still are burdened with the labor COST to replace it which is generally over $1500.

If anyone out there has a better solution or suggestion I'd like to hear it.

Thanks - Capt Bob

[BambooSailor]

it is easier to replace cone clutch on sd 50 than sd 40 where you have to unlock the engine from the silent block...

No, you do not have to unlock the engine and move it. All you need to do is to unscrew 4 nuts and push the assembly into the engine. 10 minutes max.

I am now faced with another replacement after only 180 hrs.

Did you relap it? It is DIY project. How much wear did you find on a cone?

costs me each time 2500us$ with labor

This is ridiculous. It takes me 1.5 hour to lap the cone (replacing it is even faster), most of the time is spend lowering the oil level and refilling. If you get to Seattle, I can show you how to do it, for free. Save yourself big $$$$. (As I think of it, I may be able to prepare a web page with detailed instructions, since it looks like too many fellow sailors are taken for a ride by incompetent mechanics.)

[malolo55]

Dear Bamboo sailer

I spoke to my mechanic that changed my cone clutch 18 months (180 hrs) ago. He had spoken to a Yanmar dealer in Florida after trying to pull the clutch out without moving the engine forward. They were quite emphatic and detailed about the procedure as they had done a lot of these repairs. He did pull the engine forward and is sure that is what needs to be done to replace the cone.

I have a cross section of the SD40, and it's not clear how that pinion gear can move forward to release the drive gears; so when you refer to "the assembly" which piece are you referring to? And, if your offering, I would appreciate detail on your method to replace the cone without moving the engine.

Manual attached (I hope) - cross section on page 8

Thanks - MALOLO55

[BambooSailor]

I have Yanmar 3JH3CE. Look at the attached picture It shows SD40 attached to the engine. Picture is taken from the top, aft of a boat is to the right. Two red arrows point to some long screws. There are two more below them (not visible in the picture). If you do not have these then the procedure will not work. As you can see, they are unusually long, you would think they needn't be that long (hope that some 'initiative' mechanic did not cut them!). They are attached to the pinion gear that slides inside the engine. All you need to do is to release these 4 screws all the way to the end of screws, making sure you do not remove nuts from the screws. Then gently tap/push on the screws and entire pinion assembly will move (to the left on my image) inside the engine, away from saildrive. Push them all the way as far as they go. (If you remove nuts and push too far, you will not be able to pull the pinion mechanism back!) From here is should be easy: you need to remove gear shifting mechanism (top on my picture) and 4 screws on saildrive cover to be able to remove inside assembly. Let me know.

[carter 39]

Dear Bamboosailor,
Thank you for your time and effort.
As you describe it, this is a pretty straight forward procedure and I have no doubt that many would be able to undertake it themselves.
There remains the question of how many times can one lap the cones before they need to be replaced? and what would the signs of that be?

Of course my question to Yanmar ( as yet unanswered) is why they do not come up with replacement cones that will not wear out so fast. Not being an engineer, I would imagine that simply changing the the kind of steel used for the cones , male and or female parts , should improve their durability!!? Or does the whole concept have to be reengineered?

Has anybody written to Yanmar? Should we all collectively ? After all 500 hrs/3000 miles is nothing for serious cruisers.

Marwan

[malolo55]

Dear Bamboosailor

thanks for the info - I do have the exteded bolts as shown in your photo - My mechanics are coming in this week to change the cone; I've given them the info you sent me - If all goes well we will ALL owe you a great deal of gratitude.

I'll report back to you when the job is completed, wish me luck!

Malolo55

[BambooSailor]

There remains the question of how many times can one lap the cones before they need to be replaced? and what would the signs of that be?

There is a limit described in Yanmar manual. You should meassure it every time you lap the cone. There is several milimeters allowance. I'll find out and post more details.

...simply changing the the kind of steel used for the cones ...

Cone is not made from steel, it is made from bronze alloy. If it was made from harder metal it would not 'catch & lock' and would just slip. I sure wish all this mechanism was made more robust/long lasting, but for this discussion there is nothing we can do about it. At least Yanmar should charge reasonable $$ for part that wears so fast. I know, by the time it gets to you three distributors/dealers will take their bounty (it feels so good to take advantage of somebody in need, doesn't it?), but that's not excuse, Yanmar's customer would be better served and much happier with more direct availability of this (and other) essential replacement parts. They seem as arrogant as Toyota used to be (same pattern - excellent product with serious flaws) and it will catch up with them eventually, but I assume by that time current management responsible for the situation will be gone enjoying our money.

I'll report back to you when the job is completed, wish me luck!

Good luck!

[alanglo]

I have a Lagoon 410S2 with 40HP Yanmars and SD40 Drives. We have had endless problems with the cones and our local service agents suggest replacing the SD40s with SD50s From what I have read here there would seem to be little materiel difference between the two.
Can anyone confirm this and has anyone tried alternative solutions( ZF Drive units?).
I have been at sea for over 30 years and yachting for 53 years. In my experience a piece of critical equipment in the drive chain that can fail after only 180 hours or so is not suitable for the task and as such could render Yanmar liable.
I am in contact with them re this at the moment and will report back when I get a result.

[Captain Bill]

Originally Posted by alanglo

I have a Lagoon 410S2 with 40HP Yanmars and SD40 Drives. We have had endless problems with the cones and our local service agents suggest replacing the SD40s with SD50s From what I have read here there would seem to be little materiel difference between the two.
Can anyone confirm this and has anyone tried alternative solutions( ZF Drive units?).
I have been at sea for over 30 years and yachting for 53 years. In my experience a piece of critical equipment in the drive chain that can fail after only 180 hours or so is not suitable for the task and as such could render Yanmar liable.
I am in contact with them re this at the moment and will report back when I get a result.

I agree with your assesment of the quality of these units. I have purchased the parts catalog for the SD40/50 series and all of the parts associated with the cone clutch are identical in both models. Given that fact I don't see how the SD50 series will give you any improvement. The only difference that I can see is a new bearing spacer for the SD50 and according to the parts manual the new spacer is usable in the SD40. Perhaps the bearing spacer is the key to more longevity in the SD50 and if so replacing it is likely to be much more cost effective than buying new SD50s. The part number for the new bearing spacer design is 196440-04490. I doubt this is really a solution, but you have the information. The parts catalog is copyrighted so I cannot post a copy of the page here.

I look forward to hearing the response you get from Yanmar.

[perchance]

Originally Posted by carter 39

Dear Bamboosailor,
Thank you for your time and effort.
As you describe it, this is a pretty straight forward procedure and I have no doubt that many would be able to undertake it themselves.
There remains the question of how many times can one lap the cones before they need to be replaced? and what would the signs of that be?

Of course my question to Yanmar ( as yet unanswered) is why they do not come up with replacement cones that will not wear out so fast. Not being an engineer, I would imagine that simply changing the the kind of steel used for the cones , male and or female parts , should improve their durability!!? Or does the whole concept have to be reengineered?

Has anybody written to Yanmar? Should we all collectively ? After all 500 hrs/3000 miles is nothing for serious cruisers.

Marwan

Has Yanmar tried to re invent the wheel? In Mercury Bravo stern drives (power boat application) the cone is steel and the cups are brass/bronze(?) and are able to transmit obscene amounts of horse power. The usual reason for replacement of these clutches is gear wear not clutch wear. Unless protected by patent you would think Yanmar would use something similar in their design. I realize this isn't much help to you but you should know that the cone clutch concept is sound and works well if properly engineered with proper materials.

[malolo55]

Dear Bamboo Sailor, et al

My mechanics changed out my cone clutch (01/11/11) using your method. I saved about $500 doing it this way (cost 5 hrs=$500 + materials and tax, total $1069). I have been slow to get back to you on this as I was cautioned that if the O-ring between the plate (held by the extended bolts) and bell housing should come loose, I might experience an oil leak from the S40 into the bell housing; well, so far so good. I did replace the cone as the difference in cost between lapping and new is only a few hundred bucks, so, for me, why not go new. Thanks for the tip - also, the consensous of opinion is don't "baby" it into gear - FYI - I think the short life my second cone suffered, may have been due to motoring during the Christmas parade 2010. I found out later, the gear shift lever was not fully engaged for, could have been an hour - could it have been the wine & 25 people on board?? Expensive party!!

Tx Malolo55

[arwen]

We have a Hanse 411 fitted with a Yanmar 56HP engine and SD40 saildrive. We too have had serious issues with the engine not responding when forward propulsion is required. This happens after motoring for say 3 or 4 hours and the engine is warm. we slow down to manoeuvre and then when we want more power we get no forward drive. Sometimes if we use reverse for a couple of minutes and then return to forward gear it 'clicks' back into working mode sometimes this doesn't work so we have even tried turning the engine off and this too sometimes works. I have read all the posts about other people's problems and it would seem we may need to 're-lap' the gear cones or even replace them. In an earlier post one member 'Bamboo Sailor' mentioned they may describe how to do these procedures. I would like to know this information. even if it is just to show the engineer (if that is what we end up having to get) what we want doing. (We will have language issues here in Turkey as many of the engineers will not speak English!)
Hope someone can give us some more advice soon.