Volvo Penta Saildrive isolation: how?

haydude said:
Not just sometimes, ALWAYS AND ABSOLUTELY. If they are not following a test, something has gone wrong.
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I think the very early ones may not have been. Presumably corrosion problems highlighted the need for the isolation.

Not so sure that the big stern drives on mobos are isolated..... ???
 
The below series of photos illustrate the work performed at Seaview West Boatyard by Mark Hiraiwa of Auxiliary Engine Service. Mark removed the Volvo Penta 130S sail drive that had suffered catastrophic galvanic corrosion damage from stray currents due to the faulty installation by the authorized Volvo Penta dealer in who failed to isolate the drive as mandated by Volvo Penta and repeatedly requested by the customer. Mark's meticulous work resulted in the replacement 130S sail drive being installed according to Volvo Penta specifications resulting in successful electrical isolation of the drive, thus protecting the new drive from destructive galvanic stray currents. Additionally, the drive is protected by a large protective zinc installed on the hull directly above the prop. A Volvo Penta Active Corrosion Prevention system provides continual monitoring and additional protection of the sail drive.

Link to photos and captions:

https://picasaweb.google.com/106055...&authkey=Gv1sRgCPqkj72M1b2teQ&feat=directlink
 
fastjedi said:
Some related observations / questions ....

1. My saildrive anode appears to play no part in protecting my propeller. When the propeller anode is gone the propeller is the next thing to erode despite being within mm's of a perfectly fine saildrive anode. I haven't checked the continuity between the shaft and the saildrive case or anode (yet) but it is hard to beleive they are electrically isolated, and if there are I cant imagine I could effect a change?

2. A similar boat, with a similar Volvo saildrive, with similar propeller in the boatyard doesn't have a propeller anode (Early versions on the Volvo propeller hub didn't accomadate anodes) .... and is perfectly fine. (Although it does have a ropecutter, perhaps that provides a path?)

3. If I epoxy and antifoul most of the propeller so a much smaller surface area is exposed, would damage potential reduce / would my propeller anode last longer ..... or does the anode erode at a given rate regardless of what it is protecting?
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Hi all great thread.
JeffJedi, I am in the same position as yourself,MD 2030, Prop wastes away quicker than anode, which seems to last forever, though I managed to poke a hole in it this year so I replaced this item.Covering the prop( bald alloy areas) with epoxy, smoothing and antifouling with the proper black antifouling seems to get me a season.Out of the water currently, I will do the ohms test when launched.In the dry-port in Martigues mains 230V is phased wrongly too, but I move about once launched,so I'm not to worried about this aspect.The boat is immersed max 3 months per season, so I get away with less marina pilings etc stray current.The drive is the 120SE, which reminds me that Ive snapped off the brown (stupidly plastic) dipstick, and need to order one of these,grr!Unless a forumite knows of some other threaded object I can screw down instead!
 
Faster erosion of my prop anodes suggested that the isolation between my D1-30 engine and saildrive had failed. I tested it and found the sail drive is no longer isolated.
I can see no direct connection so suspect it is the control cable which is causing the problem.
Can anyone point me to any diagrams which show how and where the insulating bush referred to above is in the morse control unit? Has anyone any experience of replacing it?
 
bobgarrett said:
Faster erosion of my prop anodes suggested that the isolation between my D1-30 engine and saildrive had failed. I tested it and found the sail drive is no longer isolated.
I can see no direct connection so suspect it is the control cable which is causing the problem.
Can anyone point me to any diagrams which show how and where the insulating bush referred to above is in the morse control unit? Has anyone any experience of replacing it?
Click to expand...

Parts diagrams at http://www.marinepartseurope.com/en/default.aspx any help ?
 
Shortly after replacing the rubber seal on my saildrive, I checked to test ( the lack of) a connection between engine and gearbox only to find a fault.
Eventually traced this to the outer of engine throttle cable which was picking up an earth from the engine block (cable clamp) and transmitting it through the throttle / gearchange mechanism back down the gearbox outer to the gearbox.
Self inflicted as I had removed the cables when pulling the engine forward to access the saildrive.
This would be worth checking anualy and especially after the saildrive seal has been replaced of engine out / throttle cable changed etc
 
Bav32 said:
Shortly after replacing the rubber seal on my saildrive, I checked to test ( the lack of) a connection between engine and gearbox only to find a fault.
Eventually traced this to the outer of engine throttle cable which was picking up an earth from the engine block (cable clamp) and transmitting it through the throttle / gearchange mechanism back down the gearbox outer to the gearbox.
Self inflicted as I had removed the cables when pulling the engine forward to access the saildrive.
This would be worth checking anualy and especially after the saildrive seal has been replaced of engine out / throttle cable changed etc
Click to expand...

Aha! Interesting. I will have to check this too then.

Would that be the spacer washers on https://www.marinepartseurope.com/en/volvo-penta-explodedview-7746500-27-8324.aspx
 
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