Sterndrive Tilt Motor Dead

[aquaphobia]

Hello,

My boat's not going well

My plans of having it in the water by Christmas were reduced to tatters long ago and now I've hit yet another problem to keep me off the water

The boat's a Shetland 570 with an OMC inboard and stern-drive (model no. 302AMRGDP); it's sat outside my house for the best part of four months now and today I got to the stage of testing the engine. However, to do this, I needed to lower the stern-drive and it seems the stern-drive motor has either jammed or died. It certainly worked when I bought the boat, as I raised the stern-drive to get it off the delivery trailer.

There appear to be two solednoids towards the back of the engine, one for up and one for down. They certainly click satisfyingly and I've checked that there's power going in and out of them. As far as I can tell, there's power getting to the motor, but the motor's in such an inaccessible place, I can't really see much more than that. I've tried hitting it with a hammer while somebody else holds down the tilt switch (a la jammed starter motor) but with no luck. When I press the tilt switch, there's a dip on the ammeter, but not a massive one...I'm wondering if this is just the solenoid drawing current, as I would have thought a jammed motor would draw more than that?

I assume the drive to the stern-drive itself is via a worm-gear, so jumping up and down on the stern-drive isn't going to help much... Is there anything else I can try? There's a plate on the stern-drive which probably covers the end of the worm-gear; if I remove that, can I get a spanner on it and turn the motor by hand? I can't for the life of me see how this motor is actually held on; if I *do* need to get it off and overhaul it, does anybody know how to remove it?

Any help/advice/sage stroking of beards will be much appreciated,

Thanks,

Paul

 

[Haut Medoc]

Re: Sterndrive Tilt Motor Dead

Welcome to iboats.....
I'm not an OMC guy so I can't help you but you are in the right because there are some here, so stick around.....​

 

[Don S]

Re: Sterndrive Tilt Motor Dead

It a Cobra drive, and the trim pump motor drives a hydraulic pump that extends the trim rams. No worm gears. Sounds like a bad motor, but till you get to it to check, it's hard to say. trace the wires from the pump to the 3 pin connector and check the connection. for power and ground.

 

[aquaphobia]

Re: Sterndrive Tilt Motor Dead

Thanks for your replies;

I'm fairly certain it's a wormgear - there are no obvious hydraulic rams etc, as you can see;

This is the gearbox which, I reckon, translates a wormgear to a cog to raise/lower the sterndrive:
http://img134.imageshack.us/img134/7895/gearboxrm3.jpg

This is the same gearbox from the other side, showing the lifting rack and pinion:
http://img90.imageshack.us/img90/3134/liftinggearlu9.jpg

The boat has been re-engined in the past, so perhaps this is the original stern-drive unit, but the engine is newer? I took the serial number from the camshaft cover on the engine - I couldn't see any numbers on the sterndrive unit.

Thanks for your help,

Paul

 

[Don S]

Re: Sterndrive Tilt Motor Dead

The boat has been re-engined in the past, so perhaps this is the original stern-drive unit,

Yea, that would have been good to know to start with, your engine SN is for an 88 engine, nothing else in your post gave a clue as to drive type or anything else, just 302AMRGDP which would have had a Cobra outdrive.

 

[aquaphobia]

Re: Sterndrive Tilt Motor Dead

Fair enough - sorry that seems to have annoyed you so much...I'm not really much of an expert on stern-drives, to be honest...

I knew the boat had been re-engined, but it had never occurred to me that it might not have had the drive unit replaced at the same time until you said about hydraulics etc.

Does anybody know how the tilt motor is fixed to the drive unit?


Thanks,

Paul

 

[whywhyzed]

Re: Sterndrive Tilt Motor Dead

....

 

[aquaphobia]

Re: Sterndrive Tilt Motor Dead

That's all fantastically helpful, thanks for that

My motor does, indeed, have at least a blue and a green wire leading from the solenoids, although I can't see the black earth cable, so there's one thing to check. My boat is 1977 vintage, so it's right on the change-over from flange mounted motor to the sort which falls apart... Having looked at my motor, I can see it's fairly liberally covered in insulation tape, so perhaps somebody has taken it out before and had it fall apart on them...

I've got a tap and die set, but I've never tried drilling out a bolt before. Like you say, it's a skill well worth learning If I take that plate off, will the worm gear just drop out? Also, if I remove the transom rubber, how tricky is it to get back in place? Do I have to re-seal it with something like sikaflex?

Again, thanks very much for all of this.

All the best,

Paul

 

[whywhyzed]

Re: Sterndrive Tilt Motor Dead

....

 

[aquaphobia]

Re: Sterndrive Tilt Motor Dead

Hi,

many thanks for your help - I replaced a corroded connector leading to the motor and tried it again. This time, there was a significant drop on the ammeter, so I deduced the motor was jammed. So, I crawled under my engine and had a closer look at the motor and found the two bolts going completely through it, which hold it to the transom plate.

However, when I removed them and tried to withdraw the motor, I found there's a spring which, I presume, is attached to the wormgear. I didn't want to damage anything, so I've left it, but how do I disengage the spring so I can remove the motor?

Any help will be much appreciated again,

Thanks very much,

Paul

 

[aquaphobia]

Re: Sterndrive Tilt Motor Dead

Just thought I'd add that, after a bit of help and hunting around on the internet, the sterndrive unit is an OMC Stringer 400 Electric Shift (from about 1977)

Paul

 

[Lyndy]

Re: Sterndrive Tilt Motor Dead

Just thought I'd add that, after a bit of help and hunting around on the internet, the sterndrive unit is an OMC Stringer 400 Electric Shift (from about 1977)

Paul

Just a little adjustment. 400/800 started in 1978.

 

[aquaphobia]

Re: Sterndrive Tilt Motor Dead

Thanks for that.

 

[whywhyzed]

Re: Sterndrive Tilt Motor Dead

s....

 

[aquaphobia]

Re: Sterndrive Tilt Motor Dead

Hi,

thanks again for your help

Should the round thing (sorry, can't think how to describe it - a soft of quarter-inch thick collet with two curving prongs sticking out of it) on the motor shaft just slide off the motor, then? If it does, how do you align it to the motor shaft when you put the motor back in again? If I end up wrecking this spring, is it possible to fit a new one?

Sorry for so many questions - everybody else I've asked about this has given up and all the marine engineers I've spoken to have told me the drive unit is so old, they've never seen one

Thanks for helping,

Paul

 

[Bondo]

Re: Sterndrive Tilt Motor Dead

is it possible to fit a new one?

Ayuh,...... Only IF you can Find 1.........

They haven't been making Parts for that drive in Many, Many Years......

 

[whywhyzed]

Re: Sterndrive Tilt Motor Dead

....

 

[aquaphobia]

Re: Sterndrive Tilt Motor Dead

Hiya,

I managed to get hold of the Seloc manual for my drive and I can see what you mean about the hammer blow coupling being jammed on both the motor spindle and the worm-gear drive shaft. Hopefully, I've not stretched the spring too badly already and a liberal dose of plus-gas will loosen it up.

Thanks again for all your help - I'll let you know if I manage to get my motor off at last


All the best,

Paul

 

[wakeboarddude]

Re: Sterndrive Tilt Motor Dead

Have you removed the cover from the gear box in the picture? Looking at the condition the drive is in, it is posssible that after sitting for some months the gears/worm gear may be seized. This is very easy to do, just four bolts. It is important when replacing the cover to use the proper gasket. I did not once and the drive wouldnt raise or lower because the cover plate was pressing too tightly against the gear. I know with mine there is always water leaking into that gear box and I do frequent oil changes, so if it was stored with water in there could be trouble. If you do find it to be a problem with the motor, i rebuilt mine last year and it was pretty straightforward. Motor comes off in one piece with the shaft which has the prongs. The motor pulls apart and can be cleaned and possibly the brushes can be replaced. If you are unsure of what to do a good electrical shop should be able to test or repair it for you.
Good luck troubleshooting, i know these OMC 400's can be a pain.

 

[aquaphobia]

Re: Sterndrive Tilt Motor Dead

Hello,

oh yes - it comes apart easily, alright

This was my first thought, actually, so I took the cover off the wormgear/clutch(?) housing and discovered to my surprise (as I didn't have a manual...and I wasn't using my brain to much effect) that it was full of oil!

The gears inside looked in surprisingly good condition (in fact, they looked brand new, which was nice), but I couldn't really tell whether they were jammed or not. I'm pretty sure the problem is the motor as the symptoms are when you press the tilt switch, half the time nothing happens, half the time there's a current spike from the motor, so it seems electrically sporadic.

When I split the gearbox, though, I discovered it had been assembled using instant gasket at some point in the past - there was no evidence of the original gasket at all. The O-Ring was also fairly badly chewed up and had been covered with silicone. I followed suit and liberally coated everything with instant gasket before bolting it all back together, but the fitting was certainly tight. Also, short of mopping up the oil from the road and trying to identify it by smell/feel/taste, I had to guess what sort of oil to replace it with. I went for general purpose gear oil, but what grade should I use? (I suppose, actually, my nice new manual would tell me that...)

Thanks for your help,

Paul