C40TLRX gear box drive shaft seals replacement

[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

[pstephens46]

31 is plastic? Strange to me.

[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

[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

[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?

[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

[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]

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

[walleye1]

Get a cheap bicycle tire pump and t a gauge in line.

[99yam40]

I have air compressors so it was easy once I found all of the fittings I needed.
turned the regulator to just 10 psi and then slowly opened the valve to the lower unit.
when it built up to 10 psi I closed the valve and watched to gauge and listened for air leaks.
I did not hear or see anything that would show as a leak. so I went and looked in service manual and saw I needed to go to 14.2 PSI.
went back to shop and the gauge had not dropped after maybe 5 minutes.

so I started slowly raising the regulated pressure and when I got to 13 psi , I could hear it coming out of the drive shaft seals and had a little water and oil coming out of the prop shaft seals.
even saw a few bubbles from the shift shaft seal.
Time to reseal the whole thing .

I will pull and inspect the shafts,bearings, and gears before I order anything

So I had to drill and use screws to pull the Shift Shaft housing and the drive shaft seal housing.
I am working on rigging up some arms to get a hold of the prop shaft carrier.

Being that the web that you hook onto on the carrier is slanted toward the outside diameter, the farther it goes back towards the prop end. Is there a special area that I need to get a hold of?

I bent a couple of bolts into a hook to grab the web so they will slide to the out side as i put a strain on the puller. I see no other way to do this right off hand.

back to the hardware store

[walleye1]

Instead of ordering a seal kit order the parts separate,there seal kit has stuff you don't need like a power head gasket.
And it is cheaper.

[99yam40]

I do not know what happened to my other post, but they might put it back.

yea I plan on seeing what all I need before ordering parts,and find the best prices
need to make sure bearings are good after having water in there

[rodbolt17]

if this motor has ever seen salt or brackish water do yourself a favor.
fuggit about pulling the carrier.
wont come out.
they made the c 40 shift in two desighns.
if your pushs and pull don't worry about it.
if it rotates left and right then pull the shift shaft.
have a machine shop make you an adapter with your slide hammer thread on one end and the propshaft thread on the other.
pull the shaft and carrier together.

[99yam40]

I was hoping you would respond Rodbolt, and thanks for the info.

I have a friend that has a lathe and welding machines, maybe he can make something for me.

I am not sure what you are saying on the
"if your pushs and pull don't worry about it.
if it rotates left and right then pull the shift shaft."
can you explain that a little better.

never mind, It just hit me.
Yes mine rotates to shift not pull up and down.

I have already pulled the shift shaft, but still no moving.
I guess I need to look at pulling the seals on the prop shaft without pulling the carrier.

I was just thinking inspecting the bearings and gears would be a good idea.
but on a 20 year old salt/ brackish motor, seals only on that would be the best to see how it plays out.

I did not find much if any metal on the drain screw, so I will hope for the best

[TownsendsFJR1300]

I gather you didn't pressure check and see where the leak is coming from first?? Would have been nice to narrow down (say it was the aluminum housing O-ring / carrier seal) then you know it has to come out...

You may have seen it already, but there's several You Tubes showing prop seal replacement using sheet metal screws after CAREFULLY DRILLLING the old seals (and yanking them).

Being a Backyardian, having a 20 year old motor, I'd try that first.. Is it the correct way-nope. Will it work, most likely...