O-Ring for cooling water on drive

[reavesga]

I went to reinstall my drive today and noticed that the O-ring for the water tube is too big. I rechecked my part number 25-33504 and that seems to be the right number at least according to my Mercruiser dealer and marineengines.com illustrated parts diagram. It is clearly too big though to fit into the machined O-ring groove on my gimbal housing. The O-ring that came out was tossed so I don't have it for comparison. I could take some ultra gray and "glue" it in place as I reinstall the drive, but that might be dicey as I am almost 100% sure I will end up pinching the O-ring between the drive and the gimbal housing. I think I should go down to my local parts house and get a smaller O-ring. Not by much but enough so it fits in the O-ring groove. So here is the question. Is that the right part number, 1972 vintage Mercruiser with 140 Hp motor and is it supposed to be too big and some magic happens at installation that forces it into the groove without pinching?

Second question. there is a big rubber ring that came out around the drive. the book shows it going into the housing first. Question, what is the seal that keeps the water out. Is it the paper seal around the bolts or that rubber ring that goes up in the housing? If my shift shaft is leaks, it looks like it is on the wrong side of the paper seal around the bolts.

Just trying to learn some philosophy on how that drive is supposed to seal up back there. Everyone says don't put ultra gray on the seal around the bolts, so I will not, but is that what everyone actually does?

 

[achris]

I went to reinstall my drive today and noticed that the O-ring for the water tube is too big. I rechecked my part number 25-33504 and that seems to be the right number at least according to my Mercruiser dealer and marineengines.com illustrated parts diagram. It is clearly too big though to fit into the machined O-ring groove on my gimbal housing. The O-ring that came out was tossed so I don't have it for comparison. I could take some ultra gray and "glue" it in place as I reinstall the drive, but that might be dicey as I am almost 100% sure I will end up pinching the O-ring between the drive and the gimbal housing. I think I should go down to my local parts house and get a smaller O-ring. Not by much but enough so it fits in the O-ring groove. So here is the question. Is that the right part number, 1972 vintage Mercruiser with 140 Hp motor and is it supposed to be too big and some magic happens at installation that forces it into the groove without pinching?

That's right 'O' ring. Yes it seems a bit big, but put some grease on to hold it in place while you put the drive back on. The 'O' ring is the size it is so the water pressure doesn't over-exert a smaller one.

Second question. there is a big rubber ring that came out around the drive. the book shows it going into the housing first. Question, what is the seal that keeps the water out. Is it the paper seal around the bolts or that rubber ring that goes up in the housing? If my shift shaft is leaks, it looks like it is on the wrong side of the paper seal around the bolts.

That big rubber ring should be GLUED into the bell housing. It's the 'last line of defnece' (for the uni joints, gimbal bearing and bellows) if the intermediate shift shaft seal or the bell housing gasket leak. Yes, if the shift shaft seal leaks (quite common on the earlier style seal. you should look at updating it) it's on the 'inside' of the bell housing gasket, and will fill the shift slider cavity.

Just trying to learn some philosophy on how that drive is supposed to seal up back there. Everyone says don't put ultra gray on the seal around the bolts, so I will not, but is that what everyone actually does?

NO sealant on the gasket.

Chris..........

 

[reavesga]

That big rubber ring should be GLUED into the bell housing. It's the 'last line of defnece' (for the uni joints, gimbal bearing and bellows) if the intermediate shift shaft seal or the bell housing gasket leak.

Should I use a thin film of ultra grey on that ring? Or bellow adhesive?

Yes, if the shift shaft seal leaks (quite common on the earlier style seal. you should look at updating it) it's on the 'inside' of the bell housing gasket, and will fill the shift slider cavity.

Is there a kit for this update? All of my shift shaft parts are in such bad shape I suspect I will remove the haft by cutting it in half and pulling the top out and letting the bottom drop out. It is for sure leaking. No way it can not be. Rubber seal is just floating up and down the shaft in the exhaust passage area. I can not see any other seal.

 

[JASinIL2006]

Bellows adhesive works great for the big rubber ring in the bell housing.

 

[achris]

...Is there a kit for this update?

Yes, part number 23-805041A2... Look HERE

All of my shift shaft parts are in such bad shape I suspect I will remove the haft by cutting it in half and pulling the top out and letting the bottom drop out. It is for sure leaking. No way it can not be. Rubber seal is just floating up and down the shaft in the exhaust passage area. I can not see any other seal.

You just break the lever and pull the screw out and save the shaft, then you just need the seal kit and the lever (part # -45518A3).

Chris......

 

[JoLin]

The surface of the big paper gasket is very, very narrow at the top. This past spring I managed to tear TWO of them at that spot putting the drive back on. When the gasket hung on the studs, the top overlapped the opening in the bellhousing by a fraction of an inch. It was enough to pinch and tear it when I slid the drive on. On the third try, I put a few dabs of permatex aviation adhesive on the gasket to hold it precisely in line with the bellhousing opening.

Not sure why I had an issue that one time on that one drive, but I'll do it again next time.

My .02

 

[reavesga]

You just break the lever and pull the screw out and save the shaft, then you just need the seal kit and the lever (part # -45518A3)

Can you provide more detail on how you do this "breaking" please? All of my parts in that area are in pretty rough shape, ie the head of the screw can barely be made out.

Also, once I get the shaft out, is the bushing hard to get out? I researched all the parts and they are all available but just wondering what the steps are after I get the shaft out of the way. Does the bushing press out the bottom, out the top, etc? Any good you tube videos on this that you are aware of?

 

[Bt Doctur]

with all your research you should have found the manual to guide you and not guess.
Usually a sharp blow on the top of the arm will fracture it
http://www.boatfix.com/merc/Servmanl/6/6B4R3.PDF#[0,{%22name%22:%22XYZ%22},-7,792,1]

 

[reavesga]

Ok. Just to be clear, cold chisel on the shift arm and hit it vertically? Thanks for the manual reference. For me manual meant selco.

 

[reavesga]

Not sure why I doubted the forum. Three hits with the chisel and the shift arm broke in two neat pieces. I think the screw is even reusable. Now the bushing that is pressed in from the top. What is magic for getting it out of there?

 

[reavesga]

Really need to know which way the old bushing needs to go to come out or does it matter? Meaning it can be pressed out either direction.

 

[reavesga]

Ok. Running commentary here, ie the play by play. I used a 7/16" socket and tapped out the upper bushing part one from below. Did not realize there were two parts to this bushing? Are there really two parts or does it just look that way? The book says removed shift shaft oil seal and bushing. I have what appears to be a small rubber seal that was just floating up and down on the shaft. I am assuming that is the oil seal. I have tapped out one constant diameter inside and out bushing. The remaining piece that also looks like a bushing has some kind of lip in it. not sure if I need to tap that piece out as well. it is hard to see from the exploded view on marineengine.com and the book just points to two pieces and says remove.

 

[achris]

Yes 2 pieces. The bushing and the seal. And as you found out, doesn't matter which way. But the new one it does. I use a1/4" bolt and nut and a handful of washers to 'press' it in.

 

[reavesga]

No Title

achris - just to make sure I have all of the parts out. here is a picture of the items I removed. Is this it or is there still a piece stuck in the drive?

 

[reavesga]

No Title

Here is a picture of the bell housing after I drove the bushing out. To me it looks like there is another item still pressed in there but maybe not. Thanks for all the assistance. I just ordered the seal kit from the link posted above and a new shift lever. Hopefully all parts will get here by Thursday, I can get her back together on Friday and water test Saturday.

 

[achris]

What's still in there is the outer part of the seal, the metal 'carrier'. Just with a screwdriver, flick it out, being careful not to marr the bellhousing.

Chris.......

 

[reavesga]

Thanks for the info. The carrier "flicked" out no problem. Hopefully it will all go back together smooth.Spent sometime today working on the motor alignment.Guess they change over time. The tool would go in but it was a real stiff two finger at best. Couple turns of down on the front jack screw and its became very smooth again. Two fingers in and out and turn. Kids could turn it no problem. Just need parts now. This coming weekend puts me two weeks our from launching for a week long river run on the Arkansas. Hoping I get it all together and have a good test run before living "camping" on board for a week.

 

[reavesga]

Chris - just confirming that the new style bushing includes the seals in the kit.

 

[achris]

Chris - just confirming that the new style bushing includes the seals in the kit.

Affirmative.