Dating my Volvo sail drive diaphragm

[dedwards]

Hi all, I’m trying to work out the age of my saildrive diaphragm. ive found a couple of dials etched into it which I presume is the date stamp but don’t really understand how to read them. The left one is pointing to 0 and also has 08 written in the middle while the right one is pointing to 5. To the right of that it seems to also say ‘up 12’.

Im not even sure if this is the date stamp and if something more obvious is hidden in a harder to access location.

 

[StevieH]

My understanding has always been that the left dial indicates the year and the right dial the month, so in your case 2008 and Month 5. You can probably test this against the age of the boat.

 

[Bav32]

Remember that the date on the seal is the date of manufacture, not the date of fitting or date first hitting the water.
Old stock?

 

[cpedw]

Is it not absolute age that counts? Or just exposure to water, in which case does time ashore not count?

 

[dedwards]

Cheers. Don’t have a date of fitting so falling back on what’s been stamped on it. I know it was sometime between 08 and 15 but hoped it was more the latter.

 

[Tranona]

Is it not absolute age that counts? Or just exposure to water, in which case does time ashore not count?

Largely irrelevant as the rubber does not noticeably deteriorate at all. The 7 year change was just plucked out of the air by Volvo in response to negative reception to the concept when they introduced it, particularly in the US. At that time there had been no long term tests to determine a realistic life and over the last 40 years or the rubber has proven to be very long lived with no real evidence of failures, nor of any significant deterioration. The weakness if there is one is corrosion of the clamping ring, but from the inside rather than outside.