Volvo DuoProp water intake hose replacement (overheat)

moonshn

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First off I would like to thank everyone for their very informative posts that helped me narrow down my problem without having to replace every part of my cooling system and spending a lot more money than I had to.

So that my post may be as informative and help others, some background:

'99 Four Winns Horizon 240 with the Volvo Penta 5.7 GSi. Boat runs great but recently would start overheating whenever at plane. Would idle fine, and would cool off immediately once off plane. At first i thought of the usual suspects: impeller, thermostat, clogged risers, bad circulating pump, obstructions in the lines, etc. After doing some research here it became obvious that the problem (a rather common one from what i understand) was the raw water intake line in the outdrive. A leak there was underwater when at displacement speeds but came out of the water and started sucking air at plane, leading to the high speed overheat.

My question for the gurus is this:

Do I have to remove the entire outdrive to replace the hose and the nipple? It is a DP-SM drive, and I'm really hoping I don't have to pull the whole thing off.

I'm quite mechanically inclined so it won't be an issue either way, just wanted to know before I started wrenching. Any helpful tips from someone who has done this before?

Thanks again,
Alan
 

moonshn

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Re: Volvo DuoProp water intake hose replacement (overheat)

Oh yeah, meant to add that I confirmed my suspicions by letting it idle on the muffs... started overheating. Also if I pushed the muffs on tight I could hear water gurgling at the nipple.
 

Don S

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Re: Volvo DuoProp water intake hose replacement (overheat)

Yes, you have to pull the drive and the bellhousding. Besides, it should be pulled yearly for standard maintenance items like alignment checks, greasing the splines in the coupler (or you will loose a coupler and get to pull the engine).
 

bruceb58

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Re: Volvo DuoProp water intake hose replacement (overheat)

Has it been pulled before? Am wondering if the person who pulled it before replaced the weird oblong o-ring for the water passage and the o-ring for the plastic part that the hose connects to.
 

moonshn

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Re: Volvo DuoProp water intake hose replacement (overheat)

It does not seem like it has been pulled before as hard a time as I'm having seperating the drive from the bellhousing. She is soaking in PBlaster right now, looking like I'll be firing up the torch in the morning.
 

moonshn

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Re: Volvo DuoProp water intake hose replacement (overheat)

One question before I tear something up. The manual didn't make it very clear, do you need to shift the drive into gear before seperating like the mercruiser drives?
 

moonshn

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Re: Volvo DuoProp water intake hose replacement (overheat)

Anybody have any tips to separate the drive from the bellhousing? I'm running out of ideas. I've tried penetrating spray, heat, hammer... there is really nowhere to pry on it.
 

bruceb58

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Re: Volvo DuoProp water intake hose replacement (overheat)

One question before I tear something up. The manual didn't make it very clear, do you need to shift the drive into gear before seperating like the mercruiser drives?
NO...but you do need to take the back cover off and disconnect the shift cable. Have you done that yet?
 

KJSmitty

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Re: Volvo DuoProp water intake hose replacement (overheat)

One question before I tear something up. The manual didn't make it very clear, do you need to shift the drive into gear before seperating like the mercruiser drives?

Concur - no,

This is primarily so you can rotate the prop shaft and facilitate drive shaft spline insertion/engagement while mounting the drive. You can still shift it even with the drive off regardless.

Can't say I have done any of the below due to my DP coming off easily each year however...



As for the stuck drive... With the six nuts removed will the drive move at all - as in if you pull it from the bottom perpendicular to the boat, as if to rotate it on the shaft ?(not turn it left/right) - most likely not but there is enough clearance to usually move it a small amount. Maybe try that leverage/direction to get it to loosen up.. :-(

Obviously a semi unorthodox method may be to carefully try and pound a thin/sharp "prying" devise between the drive and housing - like a sharp ridged putty knife etc...

- Next may be to remove one side of the bellows, your water hose, any grounding cables etc and the two pivot bolts (don't remember the proper terminology), then just remove the drive with the housing attached... I may not be completely familiar with your drive but would that work? This would allow you to work on the "drive" separation away from the boat as well as facilitate changing the cooling hose (and bellows).

Best of luck! Be careful!

Smitty
 

moonshn

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Re: Volvo DuoProp water intake hose replacement (overheat)

As for the stuck drive... With the six nuts removed will the drive move at all - as in if you pull it from the bottom perpendicular to the boat, as if to rotate it on the shaft ?(not turn it left/right) - most likely not but there is enough clearance to usually move it a small amount. Maybe try that leverage/direction to get it to loosen up.. :-(

She wouldn't budge a millimeter.

I spoke to a local mechanic who suggested that I place a block of wood between the top of the drive and the gimbal ring then run the trim up to force them apart. Running out of options I gave it a shot.

It did separate the top but the bottom two bolts were still holding. I managed to break loose the starbord side bottom one with some prying. The port is not coopeating as easily. Not wanting to do any more damage then I already have I'm just going back to cycles of penetrating spray and heat to eventually free the last one up.

Thanks for all the help y'all

-Alan

p.s. I'm not sure how good a mechanic this guy was; he recommended using a hole saw to cut an access hole in the side of the bellhousing to gain access to the intake hose without pulling the drive :eek:
 

moonshn

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Re: Volvo DuoProp water intake hose replacement (overheat)

Next may be to remove one side of the bellows, your water hose, any grounding cables etc and the two pivot bolts (don't remember the proper terminology), then just remove the drive with the housing attached... I may not be completely familiar with your drive but would that work? This would allow you to work on the "drive" separation away from the boat as well as facilitate changing the cooling hose (and bellows).

That is actually why I went to the marina today was to get the socket to remove those bolts (don't know the name either) which they of course did not have.
 

bruceb58

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Re: Volvo DuoProp water intake hose replacement (overheat)

That is actually why I went to the marina today was to get the socket to remove those bolts (don't know the name either) which they of course did not have.
1/2" hex. It looks like a star possibly but you still use the hex. I don't see how you can take off the drive very easily that way though without cutting the water hose.
 

moonshn

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Re: Volvo DuoProp water intake hose replacement (overheat)

Well, as is often the case in life there is the good news and there is the bad news.

I like to be a positive person so we'll start with the good:

I got the drive separated using the block of wood and plenty of heat, cool, spray, and tap cycles.

The bad:

A bucketful of water in the driveshaft bellows and a single ball bearing laying it.

Looking like I will be starting another thread here shortly. I assume this errant bearing is from the gimbal bearing? Very strange though because aside from the recent overheating issue the boat ran like a top.

Thanks again for the help,
Alan
 
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