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Lower Unit Leaking air - Johnson 6hp

F

FishyBC

Contributing Member
I am changing out the water pump on a 1965 Johnson 6hp (CD-22M) and have learned to always pressure test the leg before replacing the leg oil. It will not hold any air so I got the soapy water out and discovered that it's leaking somewhere I've never seen before.

see RED arrows

Air leaking - Bearing Housing Gasket.jpg

It looks like it's leaking under the Driveshaft Housing and Seal Assembly. I suspect I should change the bearing housing gasket. How difficult is it to remove this assembly to get to the gasket ? Is this a common leak area ?
 
It should just pry up just be careful you do not gouge the surfaces. You may be alright by just screwing the impeller housing down it may just stop the leak. Go ahead and put the new impeller in and put a little dish soap on the impeller and turn the driveshaft clockwise as you push down on the housing. Do not over tighten the screws they tend to strip on those older units. After it is all together put in max 8psi pressure and see how long it holds pressure. You may be just fine?
 
If you are applying pressure with the pump off, well of course it leaks. Nothing is holding the bearing housing down against the gasket. It's a wonder it doesn't blow off and hit you under the chin. Do what kim said and re-test.
 
I originally tested it with the impeller housing secured but could not see where it was leaking so I removed it and tried again with minor pressure and it just leaks out immediately. I then put the soapy water to it and eventually found it coming out under the housing. If I've had it secured down and it still leaks, I'm guessing I need to remove the driveshaft housing and replace the gasket ?
Thank you for your responses. I'm having fun with this.
 
So I have tried to pry up on the right back side of it (beside the shift shaft) which is the only spot where there is anything that sticks out enough to get a pry bar under but it won't budge. I also tried to get a screw driver to catch on the rear other side as well as a couple spots on the front side but it doesn't seem to move. I believe I can see the gasket under the housing and am good to get a new one.

Am I doing the right thing and just keep at it or is there something I'm missing ?
 
So the water pump housing would not let go and it was destroyed trying to get it out. I did however have someone that actually had one to sell me so I'm back in business. The shaft below it however came out when I was cleaning it and now it will not go in all the way so I can't get it installed again. I tried to look up what that shaft with the key on the bottom of it is called but it is no longer on the parts list for MarineEngine.
Is there a trick to getting it back in ? I've been very careful not to move the position of the prop shaft as I'm sure if it turns that means I'm taking the lower unit apart. Maybe I am already anyhow ;-)
Any suggestions would be appreciated before I go in deeper.
Thanks
 
You might as well take the skeg of the lower unit.----------The wee key has to fit in the pinion gear.-----------Any damage on the bottom of the bearing housing where the DRIVESHAFT goes through it ?--------Pictures of the bearing housing ?
 
Thanks Racerone,
I have yet to take a skeg off so I guess this is the time to give it a go. I'll pull it apart tomorrow and see how it goes.
More to come.
 
So I got frustrated enough with this that I put it away for a few months but decided I'd prefer not to row when I go fishing so I'm back at it !
I am pretty familiar with the lower unit now and how it all goes together. I have taken it apart and put it back together numerous times now. I found an excellent video on how to do a reseal of the lower unit on Youtube as well. Very well done.

https://www.youtube.com/watch?v=NxAgHSC5MEg

Now for some reason am having an issue when its all back together where something seems to be binding and it is difficult to turn the drive shaft. it turns but not easily. I put a wrench on the top spline and turn it but it does not turn freely.
I've insured that the front notch lines up with the pin sticking out of the upper section at the very front of the leg
I've tried the section at the back where the prop shaft goes through is pointed up into the lower unit as well as down into the skeg.
I did replace the spaghetti gasket.
When I have the 6 screws finger tight it moves freely and the driveshaft turns nicely.
When I tighten those 6 screws down, it starts binding again.

What am I doing wrong ? I pressure tested it and it is holding air. If I get this lower unit turning as it should, I'm in business as this thing runs amazing.
Any thoughts would be much appreciated.
 
Loosen the water pump screws and see if that frees it up. If it does, the shock absorber (under that bearing housing you had trouble with) is broken and expanded, or just expanded without being broken. Clean out the hole real good and get it in good light and peer in there to see if the spring is broken. If not broken, just press it back together and run it.
 

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Thank you fdrgator,
Unfortunately, I actually undid the screws and lifted the waterpump half way up the drive shaft so it had nothing touching the plate the impeller sits on but it feels the same. If I turn it upside down and loosen the 6 screws that hold the skeg on, it moves smoother.
 
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