SD50 Servicing Clutch

[Brickwede]

Hello all,
after 10 years of experience with Yanmar saildrive SD50 (2800h working) I will say thank you for all the ideas, which comes out from this and other forums in the internet.

All this ideas influence me to create new solutions for a better performance of my technical equippment of my boat.
My first solution was using standard industrial seals instead of yanmar originals. The second solution was using GL4 gear oil instead of the expensive Quicksilver Öl and perform right calibration when I maintain a slippery SD50 clutch.

For my next SD50 clutch service I create a special nut (2), a collar set (3-4) consisting of 0.1mm-0.2mm-0.25mm spring steel and 0.5mm-1.0mm-1.5mm copper collar , and a spline tool(1), made from extra strong aluminium.

The nut is always reusable and fixed with two M4 stud screw. Using the stronges version of loctide for the M16 nut and the M4 studs are also recommended.

With the collar set (steel and copper) I adjust the free play of the clutch to 0.2mm. It works fine since 500h.

On my web page I have created a step by step repair instruction for the SD50 clutch. Link: Reparaturbericht - Saildrive SD50 Kupplungs Refit - Hochseekatamaran Gerda Martha.
The instruction is written in german. I'm working on a translation into english. In the meantime you can choose google translator.

My next target is to replace the copper collar with bearings.

You will hear more? Write me a PN.

[Brickwede]

Update: Link to the english translation:

Repair report - Saildrive SD50 clutch refit - Hochseekatamaran Gerda Martha

[tkeithlu]

Beautiful work, Brickwede. Your first good move was the seals and oil. Yanmar didn't design proprietary seals and oil. They took both off the shelf, as can you.