C40TLRX gear box drive shaft seals replacement

[99yam40]

Yes that is the direction I was headed, using part of my lower unit lube pump, but could not find a Tee laying around and adapter to get the gauge screwed into.
gauge is a HVAC low side gauge.-30in/Hg to 120 psi, but the face is big enough that you can see easily the 0 to 10 psi.. I thought I had a smaller gauge, but cannot find it.
regulator and valves are 1/4" but gauge is 1/8 pipe i think, anyway the gauge thread is smaller that the rest of the fittings.
I will get it rigged up where quick connect to regulator, out to a valve I can block to a tee with gauge and onto the lower unit adapter

[TownsendsFJR1300]

I made a pressure "tool" sing an old aluminum (plastic will work) lower end fill,(threaded / hose slip) fitting. That screws into the lower end and actually you can use your regulator direct if just looking for the leak. And of course soapy water spayed everywhere.

For checking if it'll hold pressure, hooking that via a hose, "T"ed into a pressure gauge and a Schrader valve, you can pressurize to say 10 PSI and check it pressure stays there. A small, portable air compressor (like you'd have in your glove box), you can sneak up on that 10 PSI (or whatever it is)..

[99yam40]

Yea, I removed #34 which is oil seal cover (it is rubber)
and I see a small lip at the very top of that housing. I thought that was another part/piece, not part of the housing.

so I will try prying on that after I find a way to pressurize the housing and check for were the housing is leaking and letting water in.
I have a small air regulator I should be able to use, but cannot find the correct fittings in my shop to get it plumbed up ,so will find some tomorrow.

strange it does not show any signs of oil coming out anywhere.
I pulled the drain and had a little free water come out.The oil was not milky.

I found it milky a few months ago and flushed it out good and refilled with fresh lower lube. ran it a couple of times and it has sat for a month at least.

Towns
did you see where #30 shows the housing 2 seals and o ring come as an assembly and cost less than the housing by itself?
very strange

looks like the seals are mounted in the housing not under it, and no way they are coming out thru the top

[panasonic]

I thought there was a little groove around the smaller diameter on the top. I just carefully pry them out with a screwdriver with the blade bent slightly. The few times I have done it I felt I was going to break as it was hard to come out but it is tough plastic. Also found using two screwdrivers at once works better as it pulls it straight up and it don't get crooked in the hole.

If you do break it...it's only $30 for a new one.

You got signs of water in the gear case?

[TownsendsFJR1300]

I am finally going to reseal my lower unit, so dropped lower this afternoon and cleaned it up before trying to open, and I am not real sure how you are suppose to pull the drive shaft seal housing below the water pump. It is plastic, and I do not see anything to get a hold of to pry on it.

I believe Rodbolt in the past said to drill small holes and run screw into the plastic shift shaft seal housing #14 to pry on when pulling that.
Is that how the driveshaft seals housing should be pulled also?

It is #31 in this parts breakdown,
notice they call it a water pump housing, just like they call #21 the real water pump housing

https://www.boats.net/catalog/yamaha...casing-drive-1

before I tear it apart I will rig up a pressure tester to see where I get any bubbles so I do not do things that are not needed.

also notice how #31 the housing is more expensive that #30 the assembly that includes the housing and seals

I just see an o-ring holding it there, no bolts, etc. As you can buy all the seals, o-ring (all which is below that plastic piece) either pry or as you said, a sheet metal screw carefully inserted and pulled out..

Looking at the diagram, the two seals below that, there apparently isn't any separate "block" to remove and pop the seals out. I guess their pushed into the LU housing itself. How to get them out (with the shaft still in, again sheet metal screws?)

Does the shop manual address it at all? Or check You Tube, must be something on there (from the English guy)..

Very odd the parts #'s listed two WPs, one which obviously isn't....

Here's "Danger" addressing the issue on a Honda 30HP, should be help full:
https://www.youtube.com/watch?v=Yv33z1Gx02A

[pstephens46]

Carrier for F150 was square at top. You could spin it a bit and then have edges to tap upwards with a slide hammer. Gently

[pstephens46]

31 is plastic? Strange to me.

[99yam40]

I am finally going to reseal my lower unit, so dropped lower this afternoon and cleaned it up before trying to open, and I am not real sure how you are suppose to pull the drive shaft seal housing below the water pump. It is plastic, and I do not see anything to get a hold of to pry on it.

I believe Rodbolt in the past said to drill small holes and run screw into the plastic shift shaft seal housing #14 to pry on when pulling that.
Is that how the driveshaft seals housing should be pulled also?

It is #31 in this parts breakdown,
notice they call it a water pump housing, just like they call #21 the real water pump housing

https://www.boats.net/catalog/yamaha...casing-drive-1

before I tear it apart I will rig up a pressure tester to see where I get any bubbles so I do not do things that are not needed.

also notice how #31 the housing is more expensive that #30 the assembly that includes the housing and seals