Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 18-07-2016, 23:30   #1
Registered User

Join Date: Jun 2016
Location: Mediterranean
Boat: Beneteau Oceanis 45
Posts: 10
Are modern sail-drives less reliable? SD50 SD60

My Yanmar SD60 sail-drive has failed with clutch-slip for the second time in 300 hours, and many friends have similar problems with the much-maligned SD50. In contrast, my old Volvo gearbox was faultless for 4,500 hrs and 15 years, and we never thought about gearbox failures.

We are used to the long warranties and almost perfect reliability of the automotive industry, but the marine gearbox technology seems to be stuck in the 70ís. Since they changed from the clunky but reliable dog clutches, the friction clutches have always been inclined to slip.

The clutches are simply too small to take the torque. In the last 40 years, sail drive gearboxes have become smaller due to improved gear technology, while yachts have increased their engine power. Various designs have tried many ways to reduce slipping, using cones or multi-plates, but always with restricted size between the reverse gears.

My SD60 (built by ZF, similar to the Volvo 130/150S) is very hard to service, because the engine needs to be disconnected and moved forward. The SD50 (made by Yanmar) is a better design, as the shaft is easily removed for servicing the cones.

Reliability seems to be going backwards, is it just my bad luck, or are others having problems as well?
__________________

__________________
RichMac is offline   Reply With Quote
Old 19-07-2016, 01:17   #2
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Full time cruising. Currently in the Med.
Boat: Aluminium yacht
Posts: 10,214
Re: Are modern sail-drives less reliable? SD50 SD60

Sail drives do have advantages. They are cheaper, quieter, and take up less space, but I am not convinced the reliability is anything near as good as a conventional gear box and shaft drive system. I have seen too many fellow cruisers with serious and expensive problems.

However, I think as you note, the SD 50 is bit atypical with a particularly poor record. There was some hope that the SD 60 would be much better, but your experience with the SD 60 does not sound promising.
__________________

__________________
Our custom built cutter rigged sloop is for sale:
48' Aluminium Bluewater Cruiser For Sale

Mermaids & Anchors
noelex 77 is offline   Reply With Quote
Old 19-07-2016, 04:59   #3
Senior Cruiser
 
Emerald Sea's Avatar

Cruisers Forum Supporter

Join Date: Feb 2013
Location: Live-aboard Cruiser
Boat: Lagoon 450
Posts: 422
Re: Are modern sail-drives less reliable? SD50 SD60

Quote:
Originally Posted by RichMac View Post
Reliability seems to be going backwards, is it just my bad luck, or are others having problems as well?
Our pair of SD60s are running just over a 1000hrs each and have been champs. Absolutely no issues (knockin on wood). We have met at least 6 other yachts with Yanmar/SD60s and they too are having no issues.
__________________
Steve
SV Emerald Sea
L450
Emerald Sea is offline   Reply With Quote
Old 19-07-2016, 05:24   #4
Senior Cruiser
 
Captain Bill's Avatar

Cruisers Forum Supporter

Join Date: Apr 2008
Location: On the boat
Boat: Endeavourcat Sailcat 44
Posts: 2,211
Re: Are modern sail-drives less reliable? SD50 SD60

I've got about 500 hrs on my sd60s and no problems so far. My assessment of sail drives is that they are primarily designed for the needs of the weekend sailor, where it might take 20 years to accumulate 500 hours. They seem to be primarily designed to get one in and out of the slip, not to motor long distances. They probably meet the needs of 99% of their market.
__________________
Captain Bill is offline   Reply With Quote
Old 19-07-2016, 05:39   #5
cruiser

Join Date: Oct 2015
Posts: 285
Re: Are modern sail-drives less reliable? SD50 SD60

In my informal lurking observations on this subject, the Internet indicates that it's not the generation, but the brand, of saildrive that indicates reliability.

That is to say, it appears to me that Yanmar saildrives are far more problematic than Volvo saildrives from what i've seen on various fora.

I seem to recall that Mark Cole 'Reach' has come to the same conclusion.

FWIW I have Volvo drives that are as old as my boat (1992). I have recently done a technical modification which I have described elsewhere but essentially they are 'original.' The boat was in charter for its first ten years.
__________________
AD28 is offline   Reply With Quote
Old 21-07-2016, 13:47   #6
Registered User

Join Date: Jun 2012
Posts: 51
Re: Are modern sail-drives less reliable? SD50 SD60

i am so surprised that the SD60 also has problems- Actually not surprised! it is still a YANMAR product, although the gearbox is ZF.

However, we have developed the cure for the SD40 & SD50 slipping Cone Clutch problem!!

My earlier posts on this issue describes the reasons why the Cone Clutch starts slipping. In short it is due to play developing caused by the Copper Thrust Washers in the upper Gearbox assembly, combined with limited Gear Selector adjustment.

We have developed a SD40 & SD50 UPGRADE/REWORK KIT that uses THRUST BEARINGS (like VOLVO) in place of the Thrust Washers.
The Bearings allow a much closer setup tolerance, with reduced wear.
The Kit also includes an adjustable Selector Set Screw and Locknut.

Another improvement is an "Open Breathing" system which reduces the possibility of blowing the oil seal between the Engine and the saildrive, and also prevents water being sucked up (when cooling down after use) at the Propeller Seal.

Both my saildrives with over 2000Hrs are fitted with the UPGRADE/REWORK Kit.

If you need any further info, feel free to e mail me on panache5000@yahoo.com
__________________
Panache5000 is offline   Reply With Quote
Old 22-07-2016, 00:36   #7
Sponsoring Vendor
 
EWOL Props's Avatar

Community Sponsor

Join Date: Nov 2015
Posts: 67
Re: Are modern sail-drives less reliable? SD50 SD60

Quote:
Originally Posted by Panache5000 View Post
i am so surprised that the SD60 also has problems- Actually not surprised! it is still a YANMAR product, although the gearbox is ZF.

However, we have developed the cure for the SD40 & SD50 slipping Cone Clutch problem!!

My earlier posts on this issue describes the reasons why the Cone Clutch starts slipping. In short it is due to play developing caused by the Copper Thrust Washers in the upper Gearbox assembly, combined with limited Gear Selector adjustment.

We have developed a SD40 & SD50 UPGRADE/REWORK KIT that uses THRUST BEARINGS (like VOLVO) in place of the Thrust Washers.
The Bearings allow a much closer setup tolerance, with reduced wear.
The Kit also includes an adjustable Selector Set Screw and Locknut.

Another improvement is an "Open Breathing" system which reduces the possibility of blowing the oil seal between the Engine and the saildrive, and also prevents water being sucked up (when cooling down after use) at the Propeller Seal.

Both my saildrives with over 2000Hrs are fitted with the UPGRADE/REWORK Kit.

If you need any further info, feel free to e mail me on panache5000@yahoo.com
This is very interesting Panache5000 !
EWOL Props is offline   Reply With Quote
Old 23-07-2016, 18:05   #8
Registered User
 
Harlequin's Avatar

Join Date: Dec 2014
Location: Hong Kong
Boat: Bavaria Vision 44
Posts: 47
Re: Are modern sail-drives less reliable? SD50 SD60

Can any of this be related to the practice of selecting 'reverse' to lock the prop whilst sailing?

I admit we've always done so, to stop the drive free-spinning and fold our Bruntons Varifold prop, but I've heard advice that suggests this might be bad for the clutch. I'm guessing due to shock loading.

Full disclosure: we've replaced the clutch plates twice on Harlequin's Volvo saildrive in 2,800 hrs / 25,000 nm / 8 yrs. [Also replaced the complete saildrive after the top bearing seized, but that's another story... ]

Interested to hear others thoughts and experience...
__________________
Harlequin is offline   Reply With Quote
Old 23-07-2016, 21:17   #9
Registered User

Join Date: Jun 2016
Location: Mediterranean
Boat: Beneteau Oceanis 45
Posts: 10
Re: Are modern sail-drives less reliable? SD50 SD60

Clutch wear could be affected by the style of use. We are in Greece, and the stern first med-mooring method is quite tricky, and needs many more gear changes. With a cross-wind in a small harbour or marina, you have to be quite firm with engine thrust, which could accelerate clutch wear.

All credit to Panache for his excellent work on the SD50, fitting the longer-lasting thrust bearings. But why does it take an owner to solve the problems? Yanmar, Volvo and ZF should be taking responsibility, offering warranty periods of 1000+ hours, and designing the gearbox so there are no claims.
__________________
RichMac is offline   Reply With Quote
Old 24-07-2016, 08:12   #10
Registered User

Join Date: Apr 2015
Location: PORT CANAVERAL
Boat: GULFSTAR 53 MOTORSAILER
Posts: 41
Images: 1
Re: Are modern sail-drives less reliable? SD50 SD60

I have a #50,000 plus monohull. My 6.354 perkins diesel and inboard direct drive, with a Velvet Drive transmission with 2:1 reduction gears, now has over 20,000 hours on it, has been around the world twice, and all that has been done is change the trans fluid once a year.
I have friends that have sail drives. It seems that none of them can make 1000 hours without problems. They even have to pull their boat out of the water to work on them.
I think that it is well worth the extra money to buy a boat that does not have a sail drive.
__________________
MAJICDAN is offline   Reply With Quote
Old 24-07-2016, 10:34   #11
Registered User
 
Dulcesuenos's Avatar

Join Date: Dec 2010
Location: Florida Keys, Bahamas Bound
Boat: 38' French Cat
Posts: 2,743
Images: 4
Re: Are modern sail-drives less reliable? SD50 SD60

We have 4900 &5300 hours on our yanmar saildrive no major issues, maintenance and seals that's all. They are the smaller ones with dog clutches though.

Sent from my PLT1077G using Cruisers Sailing Forum mobile app
__________________
Dulcesuenos is offline   Reply With Quote
Old 25-07-2016, 15:30   #12
Senior Cruiser
 
Emerald Sea's Avatar

Cruisers Forum Supporter

Join Date: Feb 2013
Location: Live-aboard Cruiser
Boat: Lagoon 450
Posts: 422
Re: Are modern sail-drives less reliable? SD50 SD60

This document is well known to many SD40 & 50 owners with cone clutch issues. Ive posted it again as its been a big aid to many. Go to the link and scroll down to the other link at the bottom of the page.... Yanmar Cone Drive Repair Manual

http://www.sailblogs.com/member/leucat/
__________________

__________________
Steve
SV Emerald Sea
L450
Emerald Sea is offline   Reply With Quote
Reply

Tags
sail, sd50

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
boom less, track less staysail advice Abrain Deck hardware: Rigging, Sails & Hoisting 17 19-12-2013 08:57
450: Lagoon 450 - SD60 sail drive roetter Lagoon Catamarans 4 07-12-2013 17:00
used SD50 or new SD60? kabrisle Engines and Propulsion Systems 2 07-12-2013 16:58
For Sale: Leopard 48-Like New Sail, Boom, +SD50 Sail Dr Starblossom Classifieds Archive 0 03-09-2013 06:08
Sail-Drives or Shaft Drives? RubyBishop Multihull Sailboats 24 07-09-2009 09:14


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 23:23.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.