ZF Aluminum Gear Case, Paint or Leave Bare?

[Alex]

Hi. I’m in the process of restoring my ZF 220A gears and need some advice. 

 

When I removed the gears, one case had traces of old white paint with a yellowish primer undercoating (perhaps etching zinc chromate) and the other gear was bare aluminum.

 

I noticed some crystalized salt and white oxide dust under some of the paint on the painted gear which had pitted that particular gear in several areas.

 

I have since removed all the paint by scraping and brushing and both are bare aluminum now.

 

As we know, aluminum does create a natural oxide protective layer on its own and I am leaning towards not painting for the following reasons:

Inspection of the actual aluminum surface

No salt or moisture to get under the paint and cause unseen damage

Not a fan of spraying all over and the external parts that may need maintenance later

 

If left bare,,, after assembly of the gears, I would spray a wax coating such as CRC Heavy Rust Inhibitor or SP400 and keep them clean and as dry as possible.

 

Original salt and water came from leaking shaft seals and leaking fish box. (Both to be corrected before reinstall)

 

Thanks!

Topic

[Alex]

Thank you Tony. Seems there are both ideas out there as I see most gears painted white, matching the engine.

I would like to see the actual aluminum and address any issues sooner than later.

Ill keep them bare, clean and protected.

[Tony Athens]

We rarely paint gears–We like to them clean ( teach the operator) and wet with WD-40.. Also, bilges need to kept dry and drip free

[Author]

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