Out Drive Corrosion

[jlogger]

It seems like my anodes are not taking any beating from corrosion but my out drive is bearing the brunt instead. I pulled my prop and there is what seems to me to be excessive corrosion behind it. Last year I noticed alot of corrosion on the out drive case. I cleaned up the case and the anodes real well at the beginning of last season. Do I have some sort of grounding problem? The transom was replaced two years ago, is it possible that a grounding wire between the engine and the out drive got missed or something like that? Should I try to clean up the corrosion from behind the prop or will I do more damage than good?

 

Thanks

[L&M]

What your looking at behind the prop is actually another anode. The two 5/16 headed bolts on either side hold it in place. Also use the magnesium anodes instead of the common zink style when you replace them.

[jlogger]

L & M thanks. I think your name came up in a conversation I was having regarding this last night. I'll replace that anode with a magnesium one. One other question, what is the recommended interval for having my Alpha One out drive serviced? Not just oil change but pulling it off and doing a tear down and inspection.

 

Jack

[L&M]

There is really no need to pull a drive apart unless it is showing signs of an issue such as water intrusion, excessive metallic in the fluid etc. I do recommend the fluid be changed every season and the drive itself pulled every other to ck engine alignment , grease u-joints, input shaft (coupler) splines & ck bellows.  

[Down Deep]

One my previous boat with Mercruiser  I/O  I had similar problem  when boat was docked for long periods. Anodes get crusty coating  and stop working . Clean unit with CLR  Prime and paint . the corrosion hits bare metal fast . I  Installed electronic  Mercathode  system and that solved my problem .  you also you can spay lower unit with clear antifouling paint made for motors . x2 on L&M 's  advice .

[Chas0218]

One my previous boat with Mercruiser  I/O  I had similar problem  when boat was docked for long periods. Anodes get crusty coating  and stop working . Clean unit with CLR  Prime and paint . the corrosion hits bare metal fast . I  Installed electronic  Mercathode  system and that solved my problem .  you also you can spay lower unit with clear antifouling paint made for motors . x2 on L&M 's  advice .

Do not paint the anodes, it defeats the purpose. They should be free of any paint/coating just raw metal (zinc or magnesium).

[Down Deep]

I meant Paint the Lower Unit , not the anodes . I usually take anodes off when they get powdery and brush them shiny to bare metal , Now mostly trailer boat so they don't get too bad .