Lower Unit Drain Plug Washers

[olcah]

I have some nylon replacement washers for lower unit oil drain and vent plugs on 1950s OMC motors. They look quite stiff to me and I wonder if they actually seal?

These washers were originally fiber and the original number was 27-284. Is there still a fiber washer available with a newer number?

Thank you.

[drifter]

I have found them to work quite well. Have used them dozens of times with good results.

[olcah]

Drifter, Have you reused the same washer multiple times or do you replace each use?
Thank you.

[outboardnut]

They work for me even with reuse

[garry-in-michigan]

The nylon is actually more compliant than the fiber washers were.

• This reply was modified 4 years, 3 months ago by garry-in-michigan.

[olcah]

Thank you everyone.

[bill-mcnamara]

Excuse me Gents,
Hate to interrupt a thread, but hoping one of you will tell me how to initiate a topic and start a new thread.
It’s been a couple of years,and site has changed format since I last posted.
I have signed-in, but fail to see how to get a post started????
Any help greatly appreciated.
Bill McN,

[olcah]

Answered by Travis 🙂

• This reply was modified 4 years, 3 months ago by olcah.

[chris-p]

The nylon crush washers are meant for a one time use actually.

When you tighten them, the “crushing” is what provides the seal. They will not return to an uncrushed state. In an emergency by all means re use them. If this is for your annual gear oil change, I would not re use. These are not high end items.

[jerry-ahrens]

Sierra makes a fiber washer part number 18-2945. These are the old black fiber washers that Mercury used way back. They of course work on Mercury outboards and Mercruiser. I have used the Sierra 18-2945 on some 50s OMC gear cases when the nylon ones won’t seal. Note: the current Mercury washer is 12-19183 3. DO NOT use these on OMC motors. They are a ”one time use” only and once the drain/fill screw is loosened, then retightened, the washer will squash out. I keep some Sierra ones in stock, as they come in handy at times.

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