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270 water neck fitting and bellows replacement

am_dew

am_dew

Advanced Contributor
Sometime soon I will be removing the upper gear assembly on my 270 drive to lubricate the u-joint. While I am in there, I also plan on replacing the drive bellows and water neck fitting. Should I buy OEM or is Sierra OK?

Anything to watch out for, or hints, while removing/replacing the upper gear assembly? Should the bushing under the water neck fitting also be replaced, and if so, is it difficult to do so?

Thanks!
 
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Watch for the shims that will be underneath the transmission. They must go back in as they were.
Oil film can cause one or two to stick to the bearing retainer, and it's easy to loose one or two during the process.

You will need 4 new O-rings..... oil drain back tube, large bearing, one dip stick and one drain plug O-ring.

I prefer OEM, but Sierra is OK.

Be sure to use 30W engine oil in the drive.

The bearing crosses (u-joints) are point loaded, and in one direction ONLY...... making it difficult to know if they are OK or not by feel.
Also, the OEM bearing crosses are not serviceable. (no grease fitting on them)
Consider replacing the bearing crosses rather than lubricating them.

While in there, you may as well replace the PDS bearing.
You have a single bearing PDS, so it will come out AFT without removing the engine.

.
 
RicardoMarine said:
Watch for the shims that will be underneath the transmission. They must go back in as they were.
Oil film can cause one or two to stick to the bearing retainer, and it's easy to loose one or two during the process.

You will need 4 new O-rings..... oil drain back tube, large bearing, one dip stick and one drain plug O-ring.

I prefer OEM, but Sierra is OK.

Be sure to use 30W engine oil in the drive.

The bearing crosses (u-joints) are point loaded, and in one direction ONLY...... making it difficult to know if they are OK or not by feel.
Also, the OEM bearing crosses are not serviceable. (no grease fitting on them)
Consider replacing the bearing crosses rather than lubricating them.

While in there, you may as well replace the PDS bearing.
You have a single bearing PDS, so it will come out AFT without removing the engine.

.
Click to expand...
Thanks Ricardo. The bearing crosses were replaced not too many years ago with serviceable ones. I have limited tools and work environment, so unless it's a pretty easy job, I am just going to grease them.
 
And when you mention the O-ring for the "oil drain back tube", I'm not familiar with that term...where is that O-ring?
 
the oil that is pumped up the transmission (to cool it) drains back to the lower unit via a tube.
the tube will become visible once you have the transmission removed.

a schematic will show it.
 
This loos like a job I hope I don't have to do.

Is the cooling oil pumped when the prop is turning, or what controls the pump?
 
JimA82 said:
This loos like a job I hope I don't have to do.

Is the cooling oil pumped when the prop is turning, or what controls the pump?
Click to expand...

The slinger pump's die cast impeller is driven by the lower gear unit's "driven" gear. It is actually spring pin driven via the AFT face of this gear.
So yes.... it only pumps oil up while the prop shaft is rotating.
 
Whatever you do, DO NOT buy a Sierra fitting and gasket ! Find a Volvo dealer and buy OEM.
I wasted $45 on sierra junk, the beaded gasket didn't fit good and the hole in the water neck was to big to push down on the bead. Needless to say it sucked air.
I called customer service which was a waste of time.
I went to a Volvo dealer and got the good stuff. The gasket lays in like it should and the fitting is right, now all is good.
 
farmermike said:
Whatever you do, DO NOT buy a Sierra fitting and gasket ! Find a Volvo dealer and buy OEM.
I wasted $45 on sierra junk, the beaded gasket didn't fit good and the hole in the water neck was to big to push down on the bead. Needless to say it sucked air.
I called customer service which was a waste of time.
I went to a Volvo dealer and got the good stuff. The gasket lays in like it should and the fitting is right, now all is good.
Click to expand...

Thank you for this!
 
farmermike said:
Whatever you do, DO NOT buy a Sierra fitting and gasket ! Find a Volvo dealer and buy OEM.
I wasted $45 on sierra junk, the beaded gasket didn't fit good and the hole in the water neck was to big to push down on the bead. Needless to say it sucked air.
I called customer service which was a waste of time.
I went to a Volvo dealer and got the good stuff. The gasket lays in like it should and the fitting is right, now all is good.
Click to expand...

The OEM part seems like it is not very readily available. I found one on eBay that might be OEM...checking on that. Do you by chance remember where you got your OEM part?

Thanks!
 
.... alternatively, do what I did and convert to thru hull with an external wedge scoop/filter. While I was at it, I plumbed in a fresh water flush/winterizing "t" into the setup.
 
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