Leaking sd60 saildrives

[NoTies]

Always nice to get an answer, even if only for one side. Change mechanics.

[HereAndNow]

Originally Posted by Captain Bill

I have now completed reassembly of both drives. There was no apparent reason for the leak on the starboard drive, but the source of the leak on the port drive was quite clear, the Speedi-sleeve installed last October had cracked completely through and came off with the bearing carrier. It was not a fresh break caused by the disassembly process as the crack was coated with a bit of crud. I carefully examined the shaft and found no detectable wear under the Speedi-sleeve. Last year the mechanic had taken the drives to his shop to replace the failed upper halves and I took his word that the shafts were worn and needed to be sleeved. I'll never do that again. There was a polished line where the seal made contact, but no measurable wear. I replaced the seals on both drives and reassembled them. I pressure and vacuum tested the drive and both held pressure and vacuum. I rotated the prop shafts by hand under pressure and vacuum by hand and nothing leaked. We splash this afternoon and we'll see what happens when I put some serious RPM on them.

Any update on how the SD60's have held up since the new seals??

[Captain Bill]

Originally Posted by HereAndNow

Any update on how the SD60's have held up since the new seals??

There have been no leaks since I did the seal repairs. So far so good. but I won't hold my breath. I still have a vibration problem even though I backed off the prop pitch a bit.

[fortyninegroup]

Just want to add a couple of items here - first, the 7.5 psi test detail was critical for me. I took delivery of an SD60 to replace an SD50. I had rebuilt the cone clutch on the SD50 myself, so getting the drive out was not a big issue. When I pulled the SD60 out of the box it was shipped in, I noticed oil on the bottom inside of the box, under the foot, and oil along the leading edge of the foot. Yanmar ships the drives filled with oil. I was concerned it was jostled in delivery to the local supplier, here in North Palm Beach, or the seal between the transmission and the foot had been compromised. I put the drive in place in the hull, then with the help of the supplier, pressure tested with 7.5 psi and it held overnight. So I've proceeded with the installation and will launch in a couple of days. If Yanmar shipped the drives empty, there would be no way of knowing that there could be issues with that seal, so I'm happy that it was shipped full as it necessitated a test. I could have returned the drive but they are closed over the holiday period and the drives are scarce in South Florida right now... and who is to say the replacement wouldn't show up the same way. You might think that a 100lb ($5600) item would probably be crated and shipped vertically. Had I not read Captain Bill's posts on this, I would not have figured out a work through... thank you!

[fortyninegroup]

Launched our boat and did a 90 minute sea trial in the ICW and around the Port Of West Palm Beach yesterday. So far, all is well with the new SD60. It is smooth, there is no noise from the transmission either running or shifting. I needed to use Life Caulk Liquid between the rubber seal and the hull, as there were small voids in the hull platform that were fine under the original SD50 diaphragm. Using an 8mm thick stainless steel plate under the SD60 exposed the minor voids, as well as the gelcoat cracks around the stringer inserts. Very happy with the results so far. I added a Flexofold prop as part of the upgrade, as well as replaced the shifter with a new Seastar CH2100P. Now looking forward to putting some hours on her!

[belizesailor]

Originally Posted by fortyninegroup

Just want to add a couple of items here - first, the 7.5 psi test detail was critical for me. I took delivery of an SD60 to replace an SD50. I had rebuilt the cone clutch on the SD50 myself, so getting the drive out was not a big issue. When I pulled the SD60 out of the box it was shipped in, I noticed oil on the bottom inside of the box, under the foot, and oil along the leading edge of the foot. Yanmar ships the drives filled with oil. I was concerned it was jostled in delivery to the local supplier, here in North Palm Beach, or the seal between the transmission and the foot had been compromised. I put the drive in place in the hull, then with the help of the supplier, pressure tested with 7.5 psi and it held overnight. So I've proceeded with the installation and will launch in a couple of days. If Yanmar shipped the drives empty, there would be no way of knowing that there could be issues with that seal, so I'm happy that it was shipped full as it necessitated a test. I could have returned the drive but they are closed over the holiday period and the drives are scarce in South Florida right now... and who is to say the replacement wouldn't show up the same way. You might think that a 100lb ($5600) item would probably be crated and shipped vertically. Had I not read Captain Bill's posts on this, I would not have figured out a work through... thank you!

That tests only the prop shaft seal though...the "seal" in question here is called a "bellows" (by Volvo at least), it seals between the SD and the hull.

[belizesailor]

Originally Posted by fortyninegroup

Launched our boat and did a 90 minute sea trial in the ICW and around the Port Of West Palm Beach yesterday. So far, all is well with the new SD60. It is smooth, there is no noise from the transmission either running or shifting. I needed to use Life Caulk Liquid between the rubber seal and the hull, as there were small voids in the hull platform that were fine under the original SD50 diaphragm. Using an 8mm thick stainless steel plate under the SD60 exposed the minor voids, as well as the gelcoat cracks around the stringer inserts. Very happy with the results so far. I added a Flexofold prop as part of the upgrade, as well as replaced the shifter with a new Seastar CH2100P. Now looking forward to putting some hours on her!

True, some boats SD beds are not fared so well. Ive seen this issue before. Pretty criticla screw up as the original installs dont normally use any sealant, but rely on a very true bed surface.

When I replaced mine fortunately the beds were smooth as glass and sealed w no sealant.

[Britishsea]

Hey Captain Bill,

I'm wondering if you solved your vibration problem on your SD60 sail drives? Was it prop related in the end?

Forgive me if i'm wrong, but i recall that you have (had?) yanmar 3JH3 engines.

I have a 3JH3 with a temperamental SD40 and have been looking to replace with the SD60. But all the Yanmar compatibility charts I have seen don't list the SD60 with the 3JH3. Is it possible the vibration is btw engine out put spline and the sail drive?

For any one who knows: with appropriate engine height adjustments / conversion kits, can the 3JH3 take the newer SD60?

Thxs

Britishsea

[Captain Bill]

Originally Posted by Britishsea

Hey Captain Bill,

I'm wondering if you solved your vibration problem on your SD60 sail drives? Was it prop related in the end?

Forgive me if i'm wrong, but i recall that you have (had?) yanmar 3JH3 engines.

I have a 3JH3 with a temperamental SD40 and have been looking to replace with the SD60. But all the Yanmar compatibility charts I have seen don't list the SD60 with the 3JH3. Is it possible the vibration is btw engine out put spline and the sail drive?

For any one who knows: with appropriate engine height adjustments / conversion kits, can the 3JH3 take the newer SD60?

Thxs

Britishsea

I have had no luck solving the vibration problem. The kit they sold me in 2015 had a new damper design which I have come to believe is the source of the vibration issue. The SD40 used a polymer based damper while the new design is a steel spring type. Yanmar claims it's better because the damper type is now standardized across the line (better for Yanmar, not for us). I'm assuming that means across their sail drive and shaft drive line. I'm somewhat guessing that the spring type has issues at certain frequencies/RPMs. Mine is worst around 2000 rpm. Since the SD60s were never actually designed as a retrofit the damper in the kit is probably the standard damper sold with the 3jh5s and they are a 3000 rpm engine, not 3800 rpm. If I understand correctly the damper is tuned to rpm in the engine and the prop shaft to dampen the pressure pulses from the engine. Given that the gear ratios in the sail drive combination are not what the damper is designed for we have a vibration problem. Only a theory, but I've replaced the engine mounts and had the props re-balanced and it hasn't done anything.



I don't know if they even sell the retrofit kit anymore. I have decided that if I need to replace them again I've decided to re-engine and go to Beta.

[Britishsea]

Ok, thxs for that insight.

That is very, very interesting and may explain why the Yanmar compatibility charts seem to skip over the 3jh and the SD60 combo, whereas I have had several installers say to me they should mate up fine. I never thought about the operating rpm of the 3jh3 vs the 3jh5 as an issue.

Here is a link re. the backward compatibility of the SD60, presumably designed for Yanmar dealers:

http://geyasailing.com/wp-content/up...e-Brochure.pdf

Bill you mention that 2000 rpm is the worst for you, but that would be a very typical rpm for the 3JH5 and the prop's counter force put should be the same if the props have been de-pitched to compensate for the higher gear ratio.

Or am I missing something here?

Im going to have to either buy an old sd50 or a new sd 60 sail drive or do a total re-power in the near future. I would love to figure out this issue. The 3JH3 has been a flawless engine so I am loath to part with it (or the cash required for a full yanmar re-power).

Brit-sea

[Captain Bill]

My theory about the 2000 rpm issue is that the springs in the damper are too stiff. Being a 3800 rpm engine the HP output at 2000 rpm is substantially lower than a 3000 rpm engine at that rpm thus the pressure pulses are not as strong. I liken this to putting suspension springs for a large truck on a small pickup. Instead of a normal ride the suspension would hardly flex at all and the ride would be terrible. I think the reason it smooths out a bit at about 2300 rpm is that the amount of force on the springs per pressure pulse is now getting into the range for which the springs were designed. However, because of the rpm differences the pressure pulses are coming more often than the design rate, that the springs are never in sync with their design parameters so in never quite smooths out completely. I might be overthinking this, but that's a little more detail on my theory.



That kit in the brochure looks pretty much the sames as the one I bought. I have the 2.23 gear ratio. My props have adjustable pitch and I did reduce the pitch but it didn't seem to have any effect on the vibration.


It would be interesting to see if Belizesailor's and Fortyninegroup's engines were 3000 rpm or 3800 rpm.

[Britishsea]

Captain Bill,

thxs for your reply. Makes sense, the rpm is the same but the loading at that rpm is very significantly more.

Thxs for your input on this topic. You have saved me some potential heart ache and others on the forum community as well.

Fair winds

Britishsea

[Kiwikat]

Hi guys - we installed SD60 sail drives a couple of years ago on our 3JHE engines and had terrible unexplained vibration issues - it’s a catamaran - both had the issues. It was especially bad around 2000-2200 revs so we had to motor hard out at high revs - diesel bill that year skyrocketed. After much trial error and hair tearing the issue was solved by replacing the new saildrive mounts (which are 4x harder/denser) with our original SD40/50 saildrive mounts. Problem solved.
We did replace all of the engine mounts as well but that was all part of the trial and error process and in the end just decided to leave them on there.
Cheers

[Captain Bill]

Originally Posted by Kiwikat

Hi guys - we installed SD60 sail drives a couple of years ago on our 3JHE engines and had terrible unexplained vibration issues - it’s a catamaran - both had the issues. It was especially bad around 2000-2200 revs so we had to motor hard out at high revs - diesel bill that year skyrocketed. After much trial error and hair tearing the issue was solved by replacing the new saildrive mounts (which are 4x harder/denser) with our original SD40/50 saildrive mounts. Problem solved.
We did replace all of the engine mounts as well but that was all part of the trial and error process and in the end just decided to leave them on there.
Cheers

Where did you get the softer saildrive mounts?

[Britishsea]

Kiwikat,

thank you for sharing your knowledge with the community on this topic!

Such a quirky issue but I imagine there are number of 3JH3 owners out there who are or will be looking for sail drive replacements and currently only have the SD60 as option from Yanmar.

The 3JH3 seems like a solid engine and mine shows no signs giving up after 20 years and 2200+ hours.

Frustrating that Yanmar does not support a sail drive replacement conversion kit for the 3JH3.