Found a piece of rubber behind the prop 🧐

[R240C]

I just bought a boat and it has receipts for the Volvo Penta SX outdrive which was rebuilt 36 hours ago on the clock.

I was doing some inspecting/maintenance today and when I pulled the prop off there was a piece of rubber lodged deep down in the housing. (Pic attached) from looking at diagrams it appears that this piece is half of the water pickup tube seal.

The boat runs on the muffs with no overheating issues and revving the engine shoots plenty of water out of the exhaust, which makes me think the water is flowing at least somewhat well.

Not knowing anything about boat repair myself, I am reaching out for some help. I’m wondering if the Mechanic who rebuilt the unit maybe dropped the old seal down the shaft and that’s where it stayed. Or maybe the seal was installed wrong, cracked in half and fell down behind the prop. I assume there is a channel for that seal to fall down there. ??

Questions:

1) while on the muffs, would the engine blow water out of the exhaust and idle without overheating if this seal was bad?

2) is there a way for me to diagnose this seal/water pickup system without tearing the lower unit in half?

I’m hoping the mechanic dropped the old seal down there and everything is ok but I’d like to diagnose it test this before I take it out on the water.

sorry for the novel

Thanks in advance

2004 Rienell 240c 5.7 Volvo + Volvo Penta SX

 

[R240C]

The part number for the outdrive is 3869340

 

[dypcdiver]

You are correct it is for the water pickup tube grommet. I have no idea why the mechanic would have dropped it there, and not picked it out.
Very careless makes me wonder about the standard of the rest of the work carried out.

 

[R240C]

I looked more carefully at the invoice for the outdrive. It was actually a brand new unit, not a rebuilt one.

Although it only has 36 hrs of use, it is a few years old. I suppose this part just failed from age??

I am assuming it’s dangerous to run the boat like this even though it seems to be getting water to the engine on the muffs.

Anyway, is it difficult to open it up and access this part? Or is this something best left to professionals?

Would a straight water path from the engine to a hole in the boat work as a bypass, or does the outdrive also use the water for cooling itself?

Thanks.

 

[dypcdiver]

Not too difficult to drop the lower unit, if the grommet was broke on installation, then when on the plane you will be sucking air not cooling water. I would suspect that was from the previous lower unit. Here is a link to the manual http://boatinfo.no/lib/volvo/manuals/sx_dp-s_drive.html#/0

 

[R240C]

I would suspect that was from the previous lower unit.

Am I correct to assume that if my gromet did indeed fail, the engine would overheat while on the muffs?

I’m out here idling the boat going on 15 minutes now. Temp gauge is hovering just under 150 degrees. I did crack the hose at the impeller and there was plenty of flow coming through there.

I’ll have to get on a computer to view that document you sent me. Thank you.

 

[Lou C]

I would for sure want to make sure that was not part of the grommet that is still in the drive! I think it might overheat on the muffs but hard to tell. Most likely would with the boat on plane due to possibly sucking air. It’s not that hard to split the drive; I’ve done it on my Cobra which is very similar to the Volvo in that respect.

 

[SD2600]

If it is in fact from your current drive there are 2 ways to tell
1. split the drive not difficult to do. If your have an extra set of hands even better as it’s a lil awkward. This way you will know 100% if it’s from your drive.. use iboats parts diagrams very simple to follow
2. put your boat in the water let it warm up and get it on plane.. if I’m fact you are drawing air from this busted grommet your temp will spike. Watch your guage... this way may make some a lil nervous as it’s not 100%.. there is a chance that it may be from your drive but if it’s not sucking air your temp will be normal...

I chased an air issue with a repower. Lost a ton of time on the water....

there is a ton of knowledge on this site you came to the right place. Keep us posted

 

[R240C]

Thanks guys! For some reason I can’t open that website.

I see six bolts I can get to that look like they are holding the lower half on. Is that all there is? No special tools required?

How about a gasket between the two case pieces? Or does it have a reusable rubber gasket?

If it’s really that easy I will split it just for peace of mind instead of testing it out on a plane.

thanks again

 

[dypcdiver]

In total there are eight bolts to remove, 6 from below and 2 from above. the 2 from above are 1 at furthermost point on the exhaust cover and one just inside the gear change cover.

4 x No 18, 19 & 20 from above 5 & 6

 

[R240C]

Thank you. I have new o-rings and this grommet and will attempt this tonight.

 

[R240C]

Seemed intimidating but it was a very easy job.

I found the other half of the grommet in there. It’s strange that the water still made it up the passage on the muffs, but I’m glad I checked it all out.

Side note, looking at the invoice again, the entire outdrive was replaced as a whole unit. That means that this unit hasn’t been apart before, as far as I know. The grommet itself and all seals were soft and like new. How this fell apart is confounding unless it was assembled incorrectly.

Thanks a lot you guys. Great help here on the forums

 

[R240C]

[No message]

 

[dypcdiver]

Nice result, looks all new in the photo. Now go and have fun. We here in Spain have no idea when we will be allowed out on the sea.

 

[R240C]

Nice result, looks all new in the photo. Now go and have fun. We here in Spain have no idea when we will be allowed out on the sea.

Stay safe out there in Spain. I’m in a rural part of the US and our State water restrictions lifted today. I’ll give it a couple of days before I go out because I’m sure the crowds are out in full force since we’re all eager to get out on the water.

 

[R240C]

For those looking to do this yourself, if you can't find the Volvo gasket sealing compound you can apparently use the Permatex stuff listed below. I got this info from my own research so I may be incorrect, but this is what I used. Oriley's had this in stock as well as Royal Purple 75/90.

Permatex Form-A-Gasket Aviation Number 3 Sealant Liquid
Part # 80017