MERCRUISER 470 TRIM PROBLEM

[mateo]

I HAVE A MERC 470 OUTDRIVE. THE TRIM IS PULLING UP FINE BUT WILL NOT GO DOWN. I'VE ADJUSDED THE REVERSE INTERLOCK SWITCH,BY-PASSED IT BY PUTTING IN A DIFFERENT PUMP. BLED THE SYSTEM. THE TRIM WILL ON OCCASION PUSH DOWN BUT STILL TRAILS UP WHEN IN REVERSE. THIS PROB. HAPPENED ALL OF A SUDDEN. CAN IT BE THE RAMS? IS THERE SOMETHING I'M MISSING? NO RELIABLE BOAT SHOP NEARBY SO I'M ON MY OWN. SOMEONE HELP!

 

[bigdaddyofhouse]

Re: MERCRUISER 470 TRIM PROBLEM

Oh boy another person yelling at you guy's.<br /> LOL

 

[tommays]

Re: MERCRUISER 470 TRIM PROBLEM

you have a leak in the rams or the pump would be my best guess<br /><br /> http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf <br /><br />this is a alpha gen i manual which MAY be different but should be close to what you have<br /><br />section 5 goes over the trim system<br /><br />tommays

 

[airman]

Re: MERCRUISER 470 TRIM PROBLEM

The rams have a safety release on them for if you hit a log underway. It is a ball bearing held by a spring over a small hole. If you hit hard enough, hydraulic pressure unseats the ball and lets the drive go up. I've never seen them act up but its a possibility. Or maybe just a bad o-ring in the ram. Rebuild kits for the rams are fairly cheap and its a straightforward job.