Help

['77imp]

I have a 1977 IMP with and OMC outdrive. My electric tilt and trim failed yesterday at the lake when I was putting it back on the trailer. I can hear the pump motor (located on the front right side of the engine) but the outdrive would not raise. I see two small oil lines that come off the bottom of the pump assembly that look like they go to the motor mount...????....please explain this. I had to take the gear drive assembly apart on the outdrive so I could manually lift and tie off the outdrive in the upright position. When I pulled the cover of this off (4 bolts holding a 4" or so plate) water came out. Now...I'm no rocket scientist, although I do work for NASA, but I would think there should have been oil inside this seeing that it houses a clutch pack. Does this get its oil from the pump up on the side of the engine, or is that a seperate oil system by itself? Second, can anyone explain how this pump makes the gear drive assembly work on the outdrive? Maybe if I know this, I would be able to figure out why it's not working. Seems like the pump is not pressurizing what ever it needs to drive this screw drive assembly at the outdrive. I have attached 3 pics of the pump, the small oil lines going to the motor mount, and the gear drive assembly on the outdrive....at least I think they will attach.

Any help will be greatly appreciated.

 

[NW Redneck]

Re: Help

Your tilt and trim are actually two separate systems. The pump you hear running on the side of the engine is for the trim to change the angle of the drive while underway. It powers the two hydraulic rams that are the front engine mounts and rocks the whole engine and drive assy. together. There could be air in the lines from not enough oil in the reservoir below the motor, or the motor shaft could have stripped and is not driving the pump.

The tilt (to raise the drive for trailering) is driven by an electric motor mounted to the intermediate housing in the bilge on the port side of the boat. That motor drives a worm gear that engages the gears on the clutch pack you removed. Yes, that clutch housing should be full of oil. First check that the solinoids are working (one for up, one for down). If you have power going to the motor, it could either be the motor is corroded inside (common issue) and needs a rebuild or replacement if it is too bad. Or if it sounds like the motor is turning but nothing is happening there is a hammer blow coupling that links the motor shaft to the worm gear that could be broken.

Look for my thread here in the OMC forum called "Stringer Info" and there's a bunch of stuff I've scanned and posted about stringer drives.

 

['77imp]

Re: Help

Yes, now that I have taken some time away from the boat...posted this question here, I went back out to the boat and indeed, I found the tilt motor as you said. What I did find is that the shaft that goes through the intermediate housing from the tilt motor to the worm gear has broken. Looks like it snapped right at the coupling to the electric motor. How do I get the tilt motor out i.e. what bolts it in? I don't see any bolts going through the intermediate housing from the outside to hold that electric motor in. Please tell me that its easier than I think.

 

[NW Redneck]

Re: Help

Taking it out is as simple as removing 2 bolts. The hard part is doing it by feel while lying on your stomach and stuffing your arms under the engine! The motor is held in by two long skinny bolts (3/8" head IIRC) that pass through the motor and thread into the intermediate housing, This is also what grounds the motor. Be careful taking the bolts out as they also hold the whole motor together. The end cap that holds the brushes can fall free once the bolts are removed. If you think getting it out sounds like fun, wait until you go to put it back in! A couple of pieces of tape over the end cap help to hold it all together as you are re installing it.

 

['77imp]

Re: Help

well, pulling the tilt motor wasnt as bad as I thought. Putting it in was even easier. Now it's just getting a new worm gear shaft since mine broke right at the coupler to the motor. I found a couple on ebay. Im going to see about habing the machinist at work make me a new one as well.

Ok, so new question....my trim motor seems to be working...as in it will tilt the front of the engine up, but it doesnt stay up. It creeps down over a hand full of minutes. I don't see any fluid around the rams or under the pump like it's leaking or anything. Any suggestions?

 

[NW Redneck]

Re: Help

Sounds like the pump itself (below the motor) is letting the oil flow back into the reservoir. I'm not sure if the pump can be rebuilt or if it has to be replaced. Good luck!