Lower unit Nylon Gasket vs. Rubber O-ring?

drchpete

Seaman Apprentice
Joined
Jun 21, 2009
Messages
37
I just bought a 2001 hp Johnson (J8RVSIE) and was changing the lower unit gear oil and the "gaskets" I took off were Nylon but the "O-Rings" I bought from WM were rubber o-rings. I noticed on the parts diagram on ********** that both are listed as the same diagram number (31). Part number different but diagram number the same.

Are these interchangeable?

Is one Superior to the other?

Seems to me a rubber O-ring would form a better seal than hard Nylon. Any input is appreciated. I did search the site first but found nothing.

Thanks, Chris
 

Greg_E

Chief Petty Officer
Joined
Feb 17, 2009
Messages
416
Re: Lower unit Nylon Gasket vs. Rubber O-ring?

The newer style is the o-ring. I've used both types without issue, but the nylon is single use.
The plugs are different for the two different types. You need to use the correct seal for the plugs you have. The plug for the rubber o-ring is cupped and the o-ring sits in the recess. The plug for the nylon washer is flat with a couple raised ridges that deform the nylon to make the seal. Do not mix the two.
 

drchpete

Seaman Apprentice
Joined
Jun 21, 2009
Messages
37
Re: Lower unit Nylon Gasket vs. Rubber O-ring?

The newer style is the o-ring. I've used both types without issue, but the nylon is single use.
The plugs are different for the two different types. You need to use the correct seal for the plugs you have. The plug for the rubber o-ring is cupped and the o-ring sits in the recess. The plug for the nylon washer is flat with a couple raised ridges that deform the nylon to make the seal. Do not mix the two.

Thanks. My plugs do not have the recess and I did use the O-ring. I'll change it to the Nylon.
 
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