SX-M Second Lower Anode?

[Horigan]

I'd like to improve the corrosion protection on my joint venture '95 Volvo SX-M / OMC Cobra SX drive. It has multiple layers of paint and anti-fouling paint and each year I am priming and repainting areas that flake off due to corrosion. The main lower anode (Item 53 below) has a good electrical bond to the lower and is getting consumed. I'm using an aluminum anode since I boat in both fresh and salt water. I'm seeing there is a second anode available on the lower unit in the prop shaft bearing carrier (Item 27 below). This was apparently discontinued on later SX drives since I can't find a reference to this anode on later models and my local mechanics haven't heard of it.

Is anybody using this anode or have any thoughts on whether it's worth the $80 to gather all the parts necessary to install this anode?

 

[saaristo]

Corrosion is an issue vith Volvo drives. I know folks who have in addition to standard anodes also put small anodes in the trim cylinder ends, much like on Mercs with the difference being that its not fastened onto cylinder ends but on the ram ends, like clamped around the shafts. And tgen you need to route also connection wires depending if you got a good enough resistance value.

 

[dypcdiver]

On my DP-SM I have placed anodes on the trim cylinders rams after having to renew both cylinders due to pitting on the rams. The body of the cylinder is part of the Volvo Penta's Active Corrosion Control, but the rams and Pivot pins are isolated from protection by the plastic bushings in the leg.
Furthermore my props are suffering serious corrosion due to the nylon sleeve that also Isolates them from the Volvo Penta's Active Corrosion Control.
As far as the corrosion on the body of the Leg after 23 x 5 month seasons immersed in salt water it is not too bad.

 

[Lou C]

I’ve been thinking of adding those collar anodes to my Cobra, 20+ 6 month seasons in salt water.

 

[dypcdiver]

Lou C
For what they cost it is worth a try. If you look at the picture you can see that I cut a little of the Pivot Pin support flare to gain a bit of clearance. The first set I tried were a bit more barrel shaped they are 3/4" or 19mm propshaft anodes.

 

[Lou C]

Yes I can see that, very clever!