Stern Drive Down Problem

[wverdsha]

I know this sounds weird, but I am having problems with the drive going down on a 2006 240 DA. I replaced the entire pump unit with the solenoids last year and actually used the Merc power trim fluid. Bleed everything and worked fine for a couple weeks. Now it is acting up again. Works under dock power but fails to work after sitting at beach for a couple of hours. Battery showing 12.1 Amps to 11.9 loaded. I assume it is drawing air, because it doesn't hold settings under power (Drifting). The pump was factory New Merc with quick connects at the pump. I have to stand on the drive and then my son raises and lowers the drive until it goes down enough to use. Under power it eventually goes down. I bought the kit for troubleshooting with the gauges and it checked out when I originally replaced the unit. Both the bad and the good unit passed including the cylinder tests. Any wisdom people want to share is appreciated. My next step is to replace both cylinders.

 

[wverdsha]

I should also mention that the pump appears to sing when going down. A more higher pitch sound than going up. No problems with going up and holds in trailer mode indefinitely. No fluid around the boat when in slip.

 

[Lazy Daze]

Try disconnecting the rams from the drive. Lift the drive up and down by hand to verify nothing is binding (although from what you mention, it's probably fine). Then, with it still disconnected, go ahead and cycle the pump using the trim/tilt switch. See what happens with the rams now that they are "individually", so to say. However, it does sound like one (or both) of the rams might have broken sliders inside them.