Water pump shaft seal = maintenance item ?

[CJU]

I replaced the bearings & seal on the Yanmar YSH 12 (?) on our old boat several times and found that the shaft was grooved where the seals were. I did buy an expensive replacement shaft and all was well. I know you can buy very thin sleeves that slide over the damaged part of shafts ie saildrive shafts, to give a new slightly thicker bearing surface but wondered if they are available in such small sizes (about 8mm ?).

 

[bigwow]

I replaced the bearings & seal on the Yanmar YSH 12 (?) on our old boat several times and found that the shaft was grooved where the seals were. I did buy an expensive replacement shaft and all was well. I know you can buy very thin sleeves that slide over the damaged part of shafts ie saildrive shafts, to give a new slightly thicker bearing surface but wondered if they are available in such small sizes (about 8mm ?).

When I put new seals into one of my pumps, to save buying a new shaft, which had grooves where the seals sat, I shimmed the new seals so they sat on a different part of the shaft.

 

[lw395]

On my Yanmar, I found polishing the worst of the wear from the shaft using fine w&d paper worked OK.
I think sailing in muddy water does the seals no favours?

 

[charles_reed]

This is one case in which it is worth buying Volvo rather than Yanmar. The spring in the Yanmar seal for 1/2 inch shafts is a copper alloy, the seal in the Volvo equivalent has exactly the same dimensions but the spring is stainless steel that lasts a lot longer. Marine Power will sell you one with a stainless steel spring at a third of the price of a Volvo one, so the best of both worlds.

As I don't buy Yanmar parts, I cannot confirm that point, (but in buying from the OEM) I've found the seals for the Johnson pump have stainless springs - in hindsight the 2GM may have had a bronze spring in the seal, but that was an ITT Jabsco pump.
I expect it all has to do with the manufacturer of the raw water pump, rather than that of the engine. The SKF seals, from Crete, had ordinary steel springs and rusted within 3 months.