Yanmar SD20 Oil seals query

[FlyingScot]

I just replaced these on both of my SD20s.
I purchased from TOAD for less than $8 each for OEM Yanmar.
https://shop.toadmarinesupply.com/sh...sectionid=5160

[skipperpete]

Originally Posted by broken pete

I sure will, there is a good chance the genuine yanmar seals are not stainless either. I love the idea of using an O ring, that will be next years solution

The Oring idea works well in jabsco impeller pumps and other non critical, easy to access saltwater sealing applications but I'd avoid doing it on a saildrive propeller shaft.
The garter springs on genuine yanmar seals may or may not be stainless steel but they are certainly made from some sort of non magnetic corrosion resistant metal as opposed to the garter springs on the cheaper automotive type seals. Interestingly, out of 10 genuine yanmar seal springs only 6 showed zero magnetic attraction and the other 4 were only very mildly attracted .If you're on a tight budget just buy the outer seal as OEM and use the cheap auto supply seal on the oil side and the OEM against the salt water.
Yanmar give you the option of moving the seals relative to the propshaft wear points by putting a thin plastic spacer initially between the inner and outer seals but it can be moved further out in the housing which moves the seal further in by about 1.5mm. I've never been tempted to install seals face to face rather than the generally recommended " sealing lip and spring against liquid" convention

[a64pilot]

Being magnetic or not is not a good indication of stainless or stainless quality, very high quality stainless may or may not become magnetic during manufacture, particularly cold working
https://www.greenwoodmagnetics.com/r...ainless-steel/