Hello, John Talley here with Boats.net. Today I'm going to walk you through the
process to replace the output shaft seals on our 40 horsepower four-stroke
Mercury outboard. As you can see we've already got them separated. Now if you
need help doing that, why don't you check this unit's playlist and I can walk you
through the process. It's really pretty easy. Now let's step over look at the
parts we're gonna use and then we'll dive into this project. What I decided to
do here was instead of just ordering the specific parts that we're gonna use on
this particular project, I went ahead and ordered a seal kit that has everything
that you would need no matter which part of your lower unit is leaking. So now
that we've got our parts together, let's go over there and knock it out.
now it's important before you get started on this guys to go ahead and
drain it. Otherwise you're gonna make a big mess on your floor. So go ahead and
get that out of the way. Now let's go ahead and get our prop off. I don't know
what the torque value is off the top of my head, but I'm betting that wasn't
enough. It came off but not by much. That's why it's important to grease these when you put
them together. Get these two bolts-- 13 millimeters. We're gonna need a puller to
get this section out, and you could use a slide hammer-- I'm actually using a Yamaha
one. Just whatever you have access to just to get a little bit of tension to
where we can pop this housing out. Like I said, I think this outboard has been
sitting up for a while. Alright, let's go ahead and get this out. The good part is
that bearing feels good so I think we can just replace the o-ring and we
should be good to go. Let's tilt that down a little bit so we don't get all
that trash up in the front housing. There we go.
This surface here looks good. I think we can just get the seals replaced and
we'll be good to go. We'll clean this up just a little bit. It has a little bit of a
rough area right there. We'll use an emery cloth on it and I think we'll be
will be fine on the shaft. So before we take this apart, let's look at the depth
that they installed the seals to. The one on the inside is going all the way down
flush until it actually makes contact. And the upper one is just barely below
the edge of the carrier housing itself. Because we're going to do this without
the special tools, so we need to pay attention to what depth we put that
outer seal at. Now there's no way for me to really hold the carrier still over on
the other bench. So we're going to pop it in the vise and then pry these out.
Then bring it up. Yahtzee! And when you're getting the bottom one, keep in mind that
there's the needle bearing down below it so don't accidentally go into the
needle bearing and damage it. There. Since we already have it in the vise, let's
leave it here and go ahead and drive the new ones in. We're gonna put a little
Threadlocker around the outside edge, drive it all the way down 'til she
bottoms out, and then we'll work on the second one. And we're actually gonna use
a 21 millimeter to drive this one in. Yours may be different depending on the
thickness of your socket. That's it. Make sure that you have this edge facing out.
This goes in. I think we can probably still use the same socket. Let's get it
centered. Remember before: it just goes in maybe a sixteenth of an inch past that
outer edge, so that's what we're going for. Don't overdo it because it will be tough
to back it back out. And I think that's got it, so we're gonna stop right there.
Now let's take it over, swap out that o-ring, then we can start putting this
back together. Light layer of grease all the way around. And we want to fill in in
between the two seals. We've got our output shaft back in the housing, there's
some grease going around this o-ring, so we should just be able to slide it in
there and get it bolted down. May have to turn it a little bit to get it to line
up with the pinion gear inside. Alright, let's get this thing tapped back in.
We've got our bolts ready to go, and you do want to use a little bit of Loctite
on here. And then we're gonna torque them to 18 foot pounds.
Alright guys, that's pretty much gonna wrap this one up, but I still have some
more work to do: water pump, refilling it with fluid, and then remounting it to the
powerhead. And hey, if you need help doing those projects,
why don't you reference this unit's playlist. That way I can walk you through
the process. Listen if you need these or any other parts for your boat, why don't
you come see us at Boats.net and we can get you taken care of. If you like what
you see, why don't you hit that subscribe button that way you'll keep up with
whatever I'm working on next. We just want to say thank you for shopping here
with us at Boats.net and we will see you in the next video. Y'all have a great
day.