Gear Oil Coolers

[Mike Schmidt]

I have “stock” gear oil coolers on my 2006 330btas (saltwater boat). After reading Tony’s article recommending replacing these as a preventative measure, I’m considering it… but since they’re very expensive and there’s no indication that they’re failing, I just want to make sure this is a smart investment. What’s the consensus here on preventative replacement?

Topic

[Mike Schmidt]

Tony Athens wrote:

Personally, I do not share that opinion, at least operating in salt water and / or with the “in general” lower quality of the oil coolers that come on “todays” light weigh high HP/liter diesels.

Seems gear oil coolers that came on the old heavy iron engines never had the issuse we see today.. They were like a part that was “out of sight, out of mind”

I also believe the if one does not diligently flush with fresh water when sitting at the dock, these units should be changed out every 5 years or so regardless of engine hours.

Your call..

Tony

So that’s 5 years for the stock coolers, correct? The ones you sell are made of less corrosive material and include zinc ports so they should last indefinitely (until an issue turns up via inspection)?

[Tony Athens]

Personally, I do not share that opinion, at least operating in salt water and / or with the “in general” lower quality of the oil coolers that come on “todays” light weigh high HP/liter diesels.

Seems gear oil coolers that came on the old heavy iron engines never had the issuse we see today.. They were like a part that was “out of sight, out of mind”

I also believe the if one does not diligently flush with fresh water when sitting at the dock, these units should be changed out every 5 years or so regardless of engine hours.

Your call..

Tony

[Mike Schmidt]

Are the zincs even necessary? My neighbor also has the same engines and his gear coolers have zincs… and they never erode at all. It seem like since the water drains out of the gear cooler and also the top of the aftercooler, zincs are pointless in these locations (my top aftercooler zincs never erode either)…

[Rob Schepis]

What makes the gear cooler a little more of a delicate topic is that the failure can go undetected until damage is done. How many other sea water coolers have you ever seen without a zinc? (heat exchangers, aftercoolers, oil coolers, etc) So, it’s a gamble, just like insurance, do I spent a few hundred now for 100% pc of mind going forward?? If you want to work with what you have pull the coolers, clean them properly, inspect and pressure test and then have a zinc port machined (3/8″npt drilled and tapped) and reinstall. Then be very diligent about checking the gear oil as to level and clarity. Adding fresh water flushing to the equation going forward would be a big plus too, can then likely do without adding the zinc port.

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George Baird

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