Outdrive trim issues

[Richie]

Looking for some advice please. Have you guys got any ideas on what this problem is I've encountered today on my port outdrive...? (Sealine S28, Volvo DP)

Leg trims up and down no probs when in the marina, or when tootling along, however as soon as I get up on the plane, the leg will trim out fine but if I try and trim it back in again it either does it very very slowly or not at all (seems speed dependant). Slow back down again and all is fine, trims both ways no problems. I can't tell what noise the trim pump is making when it's not trimming down as I can't hear above the engines... but when I try with the engines off it sounds fine and all works perfectly.

The trim pump reservoir looks full so not sure I'm leaking the fluid or maybe I've an airlock?

Thanks

 

[jrudge]

I have had two issues with outdrives.

1. There is a big white fuse on the top of the engine that fuses the drive trim. My leg went intermittant and then stopped. The fuse cost something silly from Volvo or peanuts from Keypart. Unlikely to be the issue as it seems to go one way but for the sake of wobling a few wires you never know.

2. The relay that controls the drive flicks one way for up and one for down. My leg would go out, but not down. I took out the relay, thumped it and it lasted several years until the boat was sold. It is possible that vibration under speed is upsetting the relay? Could what seems slow be intermittant operation with for example the relay arcing in one direction?

You have two engines, so flipping the relay over will take a few moments and is probably worth considering before getting spanners and other esoteric things out.

 

[aquatom]

I would suspect the shuttle valve in the pump is sticking when under load. Swap pumps from side to side then test.

 

[Richie]

thanks both, will see if I can work those options out when I'm next at the boat.

one other thing is that I recently had the legs up in trailer position to get a good look at the ring anodes - could that have contributed to the issue do you think?