DP-SM Springtime Install (Upper Unit)

[dpagini]

Hey all,

Just entering my first spring with my 2000 Four Wins 248 Vista, and I need to put the Volvo Penta DP-SM drive back on the boat after I cleaned it up over the winter. I believe the previous owner did not know what an anode was, so the drive was in rough shape. After the paint job, it looks beautiful and is ready to go back on the boat.
I previously had a Mercruiser Alpha One, which had an entire gasket/seal kit, and now I'm not finding any of that for this drive. I have purchased my water intake seal (a bit of an odd shape, smaller than a baseball), and I'm under the impression that's just about all I need. I just discovered today that there are two o-rings that go on the drive shaft (far left of below picture), and I will need to get myself a pair of those. Secondary question: What is it that those seals accomplish?

What my REAL question is... how is it that water stays away from these u-joints!? The black painted part in the attached photo (bearing housing maybe?) basically slides into the pivot housing (right side picture, upper hole) which has the bellows attached to the other side. Is this just a perfect fit that keeps the water out? On the mercruiser, there was basically a gasket that went all the way around the whole connection point... what is it about Volvo that this is not needed? I just want to make sure I understand how this works, and also triple check to make sure I'm not missing some seal somewhere. After painting the drive, the photo is not my drive, but we did paint that black part I'm calling the bearing housing, and I've had a little bit of nerve that it may not perfectly fit into the hole anymore. There was some corrosion on that, so I'm thinking after removing the corrosion, the paint will take its place (maybe?).

Any help is much appreicated!



Thanks,
Dave

 

[skydiveD30571]

I cannot answer for the purpose of the o-rings on the driveshaft, except that my sx-a drive (and most, if not all, drive models) has them as well. As far as sealing the u-joint bellows, you have it correct. The bearing carrier (what you're calling the bearing housing) pushes up against the bellows lip and seals it tight. Obviously it is important that the bellows is installed correctly. As far as your paint job, I can't imagine it will cause you any trouble unless it is very grossly uneven. I've removed an reinstalled my drive several times by myself and it has always been nice and dry in there.

 

[bruceb58]

As long as that area is smooth that pushes against the bellows you should be fine. Personally, I wouldn't have painted it and lightly sanded it smooth.

 

[BRICH1260]

Make sure you get some good outdrive grease and liberally cover the drive shaft splines and cone(black painted section) before putting it all together.

 

[dpagini]

BRICH1260 Outdrive grease - like the Quicksilver 2-4-c grease would be fine?

 

[BRICH1260]

BRICH1260 Outdrive grease - like the Quicksilver 2-4-c grease would be fine?

That should do the job.

 

[dypcdiver]

To answer your question about the water getting to the "U" joints. The water is kept out by the nose of the outdrive input bearing housing butting up to the bellows which must have the lip correctly positioned over the moulding of the housing (your black painted bit) The other end of the bellows is secured by a worm drive clamp.

The purpose of the "O" rings is twofold, they hold back any water that might leak into the bellows and also create some friction to the inner ring of the gimbal bearing which the input shaft is a sliding fit into. Use light oil on these rings as grease can cause them to hydraulic and make re-assebly difficult.

The splines should be lubricated with a moly grease.

 

[dpagini]

Thanks dypcdiver
I was taking a look at my bellows this weekend, and think I see how it happens now.

Here is a photo of my bellows, and it seems like the "nose" goes against this black ring. I do see the ring pulling away a little from the edge in the top part of this picture... is that anything to worry about? I know I will have to clean the corrosion off this sleeve before I get the drive on there, but I guess I just wanted to see if I could get some eyes on this bellows seal and see if I should anticipate any problems Thanks for any thoughts you can provide, all.

 

[dpagini]

Little bump. Wanted to see if anyone has any thoughts on these bellows by view only...?

 

[BellevilleMXZ]

I would be changing that, and cleaning all that corrosion off really well.......almost looks like water laying in the bellows now? If bellows isn't seated against good clean aluminum, it will leak

 

[Bt Doctur]

https://www.marinepartseurope.com/en/volvo-penta-explodedview-7749307-44-10670.aspx

 

[BRICH1260]

Yep, separate the bellows from the housing and clean it up real good. Remove and replace the bellows, appears to be holding water. Maybe just clean and dry out if bellows new. Liberal application of grease between housing lip and bellows will help seal the two from minute gaps that could leak.

 

[bruceb58]

How old are the bellows? If they are 5 years old or older, replace it. If you had water in it at all, replace it.