Volvo Outdrive Degrading

[wofforduk]

Just asking if anyone has experience with the outdrive on a AD41-B on a DP outdrive that degrades when going along? have to constantly power up to trim the outdrive back to 0, it goes down to -6 prettly quickly (as in 10 mins or so at cruise)

There's no visible oil from the rams, whats peoples opinions- either valve block or piston seals leaking?

 

[jon and michie]

Is there any traces of oil in the water coming up to surface or is there any residue inside where the resevoir tank is.
This may help to determine where the fault lies
Jon

 

[wofforduk]

no traces as far as I could see, but then again I guess its hard to see under the water! maybe if I get someone to hit the power up/down whilst in water it might be visible if there.. otherwise ill check the reservoir! Cheers

 

[BruceK]

Good luck and let us know your findings. I have a similar problem on my starboard drive. I'm currently replacing Port rams but cannot find where my starboard issue is. Those rams are relatively new but no fluid leaks anywhere. I'm hoping against the odds that maybe a flush out and replacement of fluids may cure it but it's a long shot.

 

[jon and michie]

Have you tried just raising the leg up and down without moving this may allow you to see the oil float to the top.
It could be just a loose fitting allowing air into the system

 

[BruceK]

On mine at least the drive will only slowly drop over a few minutes if you're pushing a lot of power through it. Just raising or lowering the leg does nothing visible. If left in beach mode it may slowly drop down over several hours. No evidence of oil weepage judging from resevoir

 

[wofforduk]

To be honest we have had limited time, only bought her last summer so need to investigate further. Doesn't help that the fly bridge buttons are inop so have to go down to control them!

 

[volvopaul]

Just asking if anyone has experience with the outdrive on a AD41-B on a DP outdrive that degrades when going along? have to constantly power up to trim the outdrive back to 0, it goes down to -6 prettly quickly (as in 10 mins or so at cruise)

There's no visible oil from the rams, whats peoples opinions- either valve block or piston seals leaking?

Simple answer, either trim ram or rams leaking internally or if your lucky it’s the trim pump valves corroded in which case you will need a new pump, or swap it from the other engine assuming it’s a twin engine boat .

 

[BruceK]

....swap it from the other engine assuming it’s a twin engine boat .

You missed a promising career in IT hardware engineering Paul.

 

[wofforduk]

swap it from the other engine assuming it’s a twin engine boat .

Cheers Paul ill give it a go. Take it just lower both drives to the lowest position before to avoid an oily mess.

 

[Momac]

I swapped over the trim pumps, as suggested above, which proved the problem was the pump. I had been advised a valve replacement within the pump might fix the fault but it did no good at all. A new pump has cured it.
If you don't fully lower the leg it will fall anyway when you release the pipe to the pump......... So do fully lower the legs first .
It must be an easy job as I did it myself !