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Aq260 w275 outdrive overheat

C

captmello

Member
"I've been trying to solve

"I've been trying to solve an overheating issue for two years now. My engine will start to overheat at high RPM.
I put clear hoses on to look for air and found lots when on plane.
I know, common problem.
I replaced the Hose fitting and gasket on top of the intermediate, didn't help.
I pulled the lower and replaced the Oring at the bottom of the pivot tube, Didn't help.
After pulling the lower and resealing, when I ran it on muffs water was pouring out of the intermediate housing below the fitting and gasket I replaced last summer. Not out of that seal but down below it.

I'm thinking its sucking air at that same point.

What has happened to cause this? I read one thread that refered to worn bushings around the pivot tube causing the tube to move up and down?

Please guide me to the repair before I drill a hole in the hull and go thru hull intake!!!!"
 
"If you want to know the sourc

"If you want to know the source of air ingress, plug the drain in the lower drive below the grids, then cover the grids with duct tape, the remove the rubber hose from inside the boat (78) and pressurize the cooling circuit from the transom shield to the outdrive.

http://www.volvopentastore.com/CONNECTING_COMPONENTS_AQ_DRIVE_275/dm/cart_id.592 771787--session_id.603201913--store_id.366--view_id.325263


We can discuss the remedial action after you identify for sure the source of the air ingress."
 
"Well I took your advise and r

"Well I took your advise and rigged up a pressure test.

Sure enough, Its leaking at the top of the pivot tube. I sprayed it with windex and could see it bubbling from the same area water was coming out when I had it on muffs. I thought it was leaking from there.

I spoke to a mechanic who told me to try and add another gasket on top of the existing gasket under the transum hose fitting to try to push the sealing ring down a little further. That doesn't sound like the correct fix however. I have another gasket but have not tried adding it yet.

Anyone have any suggestions?"
 
"I don't believe in chasin

"I don't believe in chasing a negative pressure leak with positive pressure. However, do what El P suggests! It's certainly worth a shot!

If up for a slightly different approach, use a wet/dry shop vac on the system and with your clear hose idea! (Shop Vac connected at/near the Raw Water pump side.)

Look for bubbles in the clear hose when you soap the system down. Start close to the shop vac.... work your way back to the drive. When you see the foamy bubbles, you'll know the general area from where you were applying the soapy solution.

thumbs_down.gif
....... Never install two water neck gaskets one on top of the other. What the Hell is this guy thinking of? He should NOT be giving advice re; this drive system.
If you need advice, ask where you are comfortable in knowing that the people helping you have had years of experience at this. Not some schmuck that would give you an answer like that!
Now, had he made a mistake on a part number, or something like that.... I'd cut him some slack..... but this????? Sheesh!

BTW; This water neck gasket is a "beaded" gasket. This bead must fit down onto the top of the pivot tube and can not be mis-aligned.
The equal tightening of the two small screws is critical.

Also, consider corrostion between the rubber "S" hose and the actual connection to the water neck fitting. (I've seen corrosion form inside of this area and cause air infiltration)
These water neck fittings should be considered one of your routine maintenance replacement items.

Remember, some of these suction side components are above water when we are up on plane. This makes it particularly important that they be in excellent working order.

.
."
 
"As you can see in the explode

"As you can see in the exploded view, there are two gaskets (part 13) at the top of the tube. The mission of those gaskets are to protect the needle bearing (12), but if both gaskets were gone it would be possible for air to pass through them and be sucked into the raw water cooling system. However, in that case, you would get water around the retaining pawl area, which does not seem to be the case.

http://www.volvopentastore.com/INTERMEDIATE_HOUSING_DRIVE_275/dm/cart_id.5927717 87--session_id.785723599--store_id.366--view_id.325218

Personally, I would check why the gasket 29 is not sealing properly (maybe not tight enough?). Perhaps all what it needs is re-tightening, and a generous layer of Perfect Seal (or another sealing compound) on both sides."
 
"Actually El P, those two seal

"Actually El P, those two seals (p/n 181620) are indeed to protect the needle bearing and to aid in keeping the grease localized......., however, (IMO) they could be completely removed, and it will have no affect on any air leak in the sea water delivery. (of course, the needle bearing and pivot tube bearing surface would eventually fail)

The important components are; (a) the rubber O ring seal between the lower portion of the pivot tube and the lower unit housing p/n 941820 AND (b) this water neck fitting beaded gasket at the top p/n 814356.

Now, if the pivot tube has been damaged from previous disassembly/re-assembly, this could affect the sealing ability of either of these components (p/n 941820 at the bottom & gasket p/n 814356 at the top) .

Just a mention here; if the top pivot tube bushing is worn (p/n 814388), the tube may oscillate some, making it difficult for the gasket to do it's job.
As this gasket ages, it will loose some resiliency!
IOW's, the tube must remain centered in order for this gasket to perform well.




Just an FYI;
The pivot tube remains stationary with the Intermediate housing and lower unit housing...... and articulates with the drive.

The water neck fitting, "beaded" gasket and main suspension fork also remain stationary with one another.

The only component that needs to perform an articulating/rotating sealing function is the water neck gasket.
This is why it is so important for the top bushing to be in excellent condition.

."
 
"You are indeed correct, Ricar

"You are indeed correct, Ricardo. If the bushing part 11 is severely worn, that would be a source of air ingress, but also a lot of play would be noticed. In that case, the fix would be to remove the water tube and replace the bushing. I would also take the time to install a new needle bearing (unless it was in A1 condition) and seals."
 
"Well I pulled the top fitting

"Well I pulled the top fitting off to look at the beaded gasket. It looked good. I installed the new gasket with some sealent in hopes this is the problem. We'll see. I found another issue however, water in the bellow, see new thread."
 
"Finally got back to water tes

"Finally got back to water test the new seal a the hose fitting on the drive. I ran with a clear hose and got a lot of air bubbles like before.

I guess I'll try the pressure check again to confirm its still leaking at the top of the pivot tub, but I suspect it is.

You guys mentioned the top pivot tube bushing. How could I tell if that is bad? I assume replacing that bushing would require a complete dismantling of the outdrive.

What's my next move? I'm committed to fixing this problem, but don't know what my next move is.

Any advise is appreciated."
 
"Next move, IMO, would be to r

"Next move, IMO, would be to remove the transmission only first.
Now you have much better acess to the shift cable clamp and water neck hose connection..... and particularily when going back together in reverse order.

You will need to press the pivot tube from the Intermediate housing (where the actual press fit is).
This P/T is a soft alloy steel..... so use caution and nothing harder than a bread stick as your tool for removal.
Both top and bottom surfaces are critical to be in perfect condition.
Watch for/and where all of the spacers/washers go.

Once the main suspension fork has been separated, you will have acess to this upper bushing.
Also examine the needle bearing surface of the pivot tube..... replace if bad.

."
 
"Captmello, before you remove

"Captmello, before you remove the water (pivot) tube I suggest you verify first if there is a need for it. First, try removing the transmission (upper gear assembly) so that you have perfect access to the hose connector. Then, remove the hose connector and the gasket and have a look at the tube and the bushing. If there is a big play ( and I mean BIG) between bushing and tube, then this would likely be the culprit of the air ingress. But if there is just a little play, the air ingress could be due to either the hose connector gasket being installed incorrectly or the two Allen screws not being tightened properly. After you have removed the hose connector, you will see there is a groove between the water (pivot) tube and the intermediate housing. Then, if you look at the hose connector gasket, you will see there is a rib around it, and that rib must fit in the groove between the tube and the housing. After you have installed the hose connector and tightened the two Allen screws, that rib is compressed between the tube and the housing and seals the area around the tube, thereby preventing air ingress. As you see, you must either have a hell of a play or not have tightened the hose connector correctly for that gasket not to seal around the tube."
 
"El P, I fully agree with your

"El P, I fully agree with your logic on this.
One additional thing that occurs as this ribbed or beaded gasket ages, is that it looses resiliency..... and then no longer seals this area if, and I say IF, there is "Big Play" as you say. With Big Play, this bead/rib would need to be extremely resilient..... and they just aren't..... well, not for long, anyway!

As with much of this AQ series work, there are always other benefits in doing a task like this.... for example, cleaning up the reverse latch unit, checking the needle bearing condition, the seals at same area, the pivot tube needle bearing surface, etc. and so on...... not to forget the lowest pivot tube/lower unit O ring seal and the two lower unit O rings as a result of the R & R.

I don't want him to do more work than necessary, but you can see some of the benefits if he were to do this. I also realize that this may be easy for me to suggest when it may not be as easy for the DIY guy to take on.

."
 
"Ricardo, I agree with your po

"Ricardo, I agree with your points. I just assumed by reading the first post of the thread that all relevant o-rings and gaskets (except the ones for the needle bearing) have been changed within the last two years, including the water hose connector gasket. This is why I suspect it could be either wrong installation of the ribbed gasket, or insufficient tightening of the Allen screws, or even a BIG play between the tube and the housing."
 
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