Super Frustrated and no clue where to go from here`

Good morning all, Sorry if I posted this in the wrong thread. But I have a 1986 Volvo Penta 275. She is a older boat with a new motor and runs like a dream. Problem is that she keep overheating. I changed the raw water impeller, the water pump. Now here is the problem. I have located the "clam shell" attached to the steering fork and changed the gasket at the top half, but for reasons I don't understand the "O ring" that fits underneath the gasket and stops it from air leaking keeps getting destroyed. I take off the top gear housing, change it all over, run it in a tub and get great results, as soon as I take it out on the lake and start to play with my kids on a tube, she starts to overheat. Im wondering if there is some way to to stabilize the water inlet tube so it doesn't pound against that o ring and blow it apart. Thank you so much for your consideration.

Looong loooong ago, I abandoned thru leg water pickups on all my boats ( except my lamented Bertram 25 I/O) in favor of thru hull pickups. If done properly they are maintenance free and virtually bullet proof.

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zombiejhnconnor said:

Good morning all, Sorry if I posted this in the wrong thread.
You are posting your thread in the correct Forum.

I have a 1986 Volvo Penta with a 275 drive. She is a older boat with a new motor
What engine?


Problem is that she keeps overheating. I changed the raw water impeller, the water pump. Now here is the problem. I have located the "clam shell"
What you are calling a "Clam Shell" is actually the water neck fitting.

attached to the steering fork
The water neck fitting is attached to the upper area of the Main Suspension Fork. The Collar Steering Fork is above all of this.

and changed the gasket at the top half, but for reasons I don't understand the "O ring" that fits underneath the gasket and stops it from air leaking keeps getting destroyed. I take off the top gear housing, change it all over, run it in a tub and get great results, as soon as I take it out on the lake and start to play with my kids on a tube, she starts to overheat. Im wondering if there is some way to to stabilize the water inlet tube so it doesn't pound against that o ring and blow it apart.
That vertical tube is the "pivot tube".

You likely have an upper pivot tube bushing that needs to be replaced. When the bushing becomes worn, the pivot tube will oscillate causing the Beaded Gasket to NOT seal correctly.

Click to expand...

I was just looking at that also pull the water neck fotting and grab the lower gearbox and lift up and down if the pivot tube wiggles you need to tighten it up. Pull the lpwer gearbox then remove the tube replace anything thats worn out. Besure and put allnew orings on both the upper and lower gearboxes and pay close attention to the shims for the upper bearing in the lower gearbox. Don't forget to put the coupler between the verticle shafts when you install the upper gearbox

Unfortunately, in order to replace the upper bushing both the transmission and the lower gear unit must be removed.
Once removed, the main suspension fork hinge pins must come out.
Now you can take the Intermediate housing to your work bench and remove the pivot tube.
This will allow you to R&R the upper bushing.

Reassemble in reverse direction, installing the transmission last.
And yes..... all new O-rings!
Also, watch for the shims underneath the transmission...... they must all go back in!

NOTE:
the pivot tube is soft....... use brass tools to gently drive it downward and out.



.

I was debating on a thru hull pickup, just unsure the overall cost vs ease of that, compared to the pulling of the entire outdrive, to rebuild it sounds like I'm in for it either way

So I pulled the top gear box off and all that's left is the intermediate housing,, once I pull the lower unit, It should be smooth sailing from there correct?

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zombiejhnconnor said:

I was debating on a thru hull pickup, just unsure the overall cost vs ease of that, compared to the pulling of the entire outdrive, to rebuild it sounds like I'm in for it either way
OK..... the OEM seawater delivery system is good, and is typically trouble free.
However, with any marine application, we will see what are referred to as "wear items" that must be routinely replaced.
The AQ series Water Neck fitting is one of these!
The AQ series upper pivot tube bushing is another.


Thru-Hull pick up -vs- OEM:
.... OEM will pull water from a deeper and colder source. This water is less likely to be contaminated with floating debris.
.... The Thru-Hull fitting will pull surface water that is warmer and may possibly be more debris laden.

Your call!

Click to expand...

zombiejhnconnor said:

So I pulled the top gear box off and all that's left is the intermediate housing,
You should be left with the Intermediate housing AND the Main Suspension Fork.
Gently press the two hinge pins from the transom shield's hinge pin ears.

NOTE:
The hinge pins are also soft stainless steel.
DO NOT drive on them with any harder than an Italian Bread Stick.
If you use a steel drift punch, and if you were to expand them, they will be very difficult to remove.


, once I pull the lower unit, It should be smooth sailing from there correct?
You will need to gently press the pivot tube from the suspension fork. You may feel resistance from the fit into the Intermediate housing..... if so, this is normal.
The reverse latch and it's bearing sleeve will become free.
Once the pivot tube is completely removed, you will have open access to the upper bushing.

Click to expand...

Rick you are simply awesome man.

So a quick update, I followed instructions and now have my suspension fork free from my intermediate housing,, came out really smooth, little to no resistance, Also the Two hinge pins from the transom pin ears were super easy to pull out.
The only problem I am having now is deciphering the amount of "bushings" I need. I have only two small "washers", one plastic and the other is rubber that were on top and bottom of the reverse lock mechanism. I have been searching online for the appropriate bushing but am completely lost, according to what I have found there is only the #11 bushing, it seems like there is a ton of play at the top of the water tube, which is the cause of my the air leak. can I just buy two of the #11 bushings and place one on top and bottom of the hole at the top of the suspension fork.

All help is super appreciated and is literally saving my kids summer. Thank you all for all advice

Okay well here it is,, I have successfully found my underlining issue, lack of mechanical forsite, ( fancy way of saying I'm stupid),, so the #11 bushing,, yea i put that in upside down, and on top of the suspension fork,, turns out it's supposed to go on the water tube at the bottom of the top hole of the suspension fork,, thank you all for your efforts and input, I greatly apprciate it,, all of my frustration for a 10 dollar part i put in the wrong spot,, ,yup humble pie taste good

Yes.... the bushing flange will be facing down, and will fit up underneath the upper cross section of the main suspension fork when fully inserted.


The SS washer and the two white nylon spacers must go back as they were.

Is the water neck fitting in good shape? Now would be the time to replace it new with a beaded gasket!

Yes..... ditto Kim.

Just to be clear...... when the upper pivot tube bushing goes bad, the pivot tube may oscillate caused by the poor fit.
If so, this will eventually prevent the bead from sealing against the pivot tube, hindering the seawater pump's suction efforts.
(one tiny suction breach will kill the seawater pump's function)

So...... after replacing the upper bushing and doing your re-assembly, you will replace the water neck fitting.
You will be installing it with a new special "beaded" gasket underneath it.
The "bead" faces down, and will seal against the upper area of the pivot tube.
(this is why the pivot tube cannot become damaged during removal)

Apply a bit of water proof grease on the beaded area only.

Also apply grease or thread sealant to the threads of the two fasteners as to help prevent thread corrosion for future.