Lower unit drain plug seals

[metriccrescentwrench]

1981 Johnson 90. Bought new seals for my lower unit drain plugs from OMC dealer with part numbers I had looked up on the BRP website. Seal for top plug looks right, the one that came off was black material, new one looks to be nylon.

Bottom one is definitely wrong, they sold me an O-ring and there's no way that's going to fit. The seating face of the plug is grooved. What's really got me puzzled is that no seal came off with the plug. There's something on the lower unit seating face though, looks to be very thin soft plastic, light blue in color. Is that the old seal? (I'm afraid to go ripping things apart until I have the new seal in hand). Anyone know the part number of the proper seal for this?

By the way, the gear oil that came out looked to be in good shape, no sign of water.

thanks

 

[rickdb1boat]

Re: Lower unit drain plug seals

I believe the o-ring is for the magnetic drain plug. Vent plug washer is part #0311598 and is a nylon washer. This may also fit the Drain/Fill screw. And yes, remove the old washer from the lower unit..

 

[metriccrescentwrench]

Re: Lower unit drain plug seals

OK, I got a photo of the drain hole on my lower unit. The camera's flash helps show it much better than what I could see it "live", it definitely looks like someone just put the plug in with RTV. Also here's a photo of the drain plug and the O-ring that the dealer sold me.

So maybe the question I should be asking is "should the drain plug use the same washer as the vent plug?"