Changing Lower Unit Oil

[ineedacottage]

I changed the lower unit oil in my 1990 90hp Johnson last fall when winterizing it. I did not replace the washers on the drain plug and vent(?) plug at the time because I did not have any. I think I read on here that it is a good idea to do so...what is the reasoning behind this?

I picked some up today and the washers they gave me at the dealer here are just clear plastic washers...is this all they are? The ones on there now are blue in color and feel different then the hard clear plastic ones they gave me...what should be used...?

Thanks!

 

[iwombat]

Re: Changing Lower Unit Oil

They gave you the right ones. Put 'em in and go boating.

 

[Silvertip]

Re: Changing Lower Unit Oil

The reasoning behind changing them is once removed, they may be deformed, cracked, chipped, torn, or just damaged to the point where they might hold oil in (and maybe not) but worse, may not keep water out. If you ever get a milky looking substance or just plain water comes out before the oil starts to run, the washers might be the problem. Water in the gear case is a baaaaad thing.

 

[ineedacottage]

Re: Changing Lower Unit Oil

Thanks guys. I thought that would be the reasoning; I would have thought that washers would last longer, but I guess when it is sitting in the water, better safe then sorry for such a cheap part!

 

[tashasdaddy]

Re: Changing Lower Unit Oil

at 50 cents a piece, cheap insurance. i get them by the dozen, where did i put them?

 

[ineedacottage]

Re: Changing Lower Unit Oil

I changed the washers to the new clear plastic ones I picked up, but one question - how tight do I make the screws...? I do not want to strip them, but I sure as heck don't want water in there either!

 

[licketdsplit756]

Re: Changing Lower Unit Oil

I changed the washers to the new clear plastic ones I picked up, but one question - how tight do I make the screws...? I do not want to strip them, but I sure as heck don't want water in there either!

use your judgement just as you would tighten any screw snug is a good word i like to use.

 

[ineedacottage]

Re: Changing Lower Unit Oil

use your judgement just as you would tighten any screw snug is a good word i like to use.

Sounds like common sense that sometimes is not so common!

Thanks!

 

[nhtrax]

Re: Changing Lower Unit Oil

Years gone by glad i read all these comments buy washers:redface:

 

[WIMUSKY]

Re: Changing Lower Unit Oil

I changed the washers to the new clear plastic ones I picked up, but one question - how tight do I make the screws...? I do not want to strip them, but I sure as heck don't want water in there either!

I've never stripped one and I use a good size screwdriver to tighten them right down.

 

[northernmerc]

Re: Changing Lower Unit Oil

I doubt if one can overtighten the drain plugs. The slotted screwdriver will slip before that happens. Loosening the plugs often is another matter. They seem to tighten up from the beginning to the end of the season.

I've noticed that Mercs use the blue paper type gaskets. The Johnson that I bought this year uses the clear plastic gaskets. Yet the gaskets and bolts are the same size, so the gaskets should be interchangeable.

What tends to happen with the paper gaskets is that they separate and can't be reused for that reason. The clear plastic gaskets seem more durable and I would not hesitate to reuse them if they appear in good condition.

I've been known to add a few layers of teflon tape to the threads of the drain bolt when the gasket seems a bit questionable and I don't have another one handy. Now someone can tell me why using teflon tape is a bad idea. I'm all ears.

 

[petryshyn]

Re: Changing Lower Unit Oil

Teflon tape was designed to be a lubricant for pipe thread. It won't effectively seal a SAE thread as you need....