# Old lower unit oil



## Seda (Apr 1, 2014)

I have a 20 hp, 4-stroke outboard that has been sitting in my garage, unused, for about 4 yrs. (I run it on a water hose every month or so). As I knew it would be sitting for some time, I put new motor oil and lower unit oil in it when I put it in storage. I just bought a boat for it and will resume normal use. I know I need to change the engine oil regardless of hours. How about lower unit oil? Does lower unit oil degrade with time as engine oil does? 
While I’m asking the question, does old lower unit oil go bad in the jug?
Thanx.


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## Smackdaddy53 (Dec 31, 2012)

It should be fine but something that cheap and easy to change that is questionable would be changed if it were mine but I’m crazy OCD about things like that. It must be a good practice because my stuff lasts a long time.


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## Seda (Apr 1, 2014)

Good point. I lean to the side of caution as well.


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## Loogie (Jul 24, 2019)

The oil should be changed, after 4 years, definitely. Oil absorbes moisture and and looses some of its designed qualities. Smack's instincts are correct , oil is cheap, compared to running equipment with oil that has lost some of its designed qualities.


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## CKEAT (Aug 26, 2015)

No doubt, change it. I would change it once a year no matter the hours.


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## Ben Sheppard (Feb 1, 2020)

Listen to the Loogie. Regardless of low hours replace engine and lower end oils minimum of once a year. The oil does absorb moisture and contamination will foul surfaces. Oils have cleaners that scrub surface . Oils also have chemicals to keep those scrubbed of wear particles in suspension.
With respect to all the costs associated with the engine and lower end unit oil is very inexpensive.

as for oil on the shelf used good judgement on when to toss it


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## Seda (Apr 1, 2014)

Thanks for the replies. I’m headed to the Suzuki dealership today. Eager to get my new toy in the water.


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