OMC Stringer Problem

Hello,

yes, I thought they might be talking about a different drive - the Stringer 400/800 definitely has the waterpump at the join between the upper and lower units...

Yes, my drive is electric shift - does that make a difference?

Thanks,

Paul

 

Have you dropped the lower unit yet to see your pump and where the oil is coming out from
Dont forget the shift wire......

 

Hello,

I've taken the leg off today (which came off incredibly easily!) and now have it in the back of my van...

I'm in two minds whether to split the leg myself or get somebody who knows what they're looking at to...well...have a look at it.

...I'll probably end up seperating the upper and lower units just to have a look inside, anyway...

Cheers,

Paul

 

One of the big problems with the stringers drives is the tendency to just replace the waterpump impeller, this always always always causes leaks. You should replace the entire pump kit. It sounds like the unit wasn't maintained all that well. It would be a good idea to reseal the entire upper gear housing. It is not all that tough, about 3 hours start to finish. Other than a seal installer no special tools needed either. Just be sure to pay attention to the shimming on ball gear and check all the bolt hoses for corrosion. You may have to helicoil some of the holes on the end caps. Be sure whoever does the work has an inch pound torque wrench for reassembly, it is not hard to strip those aluminum pathways.

While the OMC stringer units are old technology, there are a lot of them still around so that says something for their design and construction. Parts are plentiful and fairly inexpensive. Seloc seems to have the best available manual that I have found if you cannnot get an oe OMC unit. The most important section of the manual is of course the one on maintenence.

Best of luck, pm me if you need to.

 

Hello,

thanks for the info!

I've been trying to find somebody willing to work on it for me and nobody will touch it with a barge-pole In fact, the last marine mechanic I spoke to gave me his stand for working on stern-drive legs rather than tackle the thing himself!

Seeing as I can't possibly make it any worse than it already is, I'm going to split the case and try to fix it myself, so your advice is very much appreciated. I've had the boat for almost a year and a half now and, in all that time, I've had it in the water for one afternoon

All the best,

Paul

 

What does it all mean?

Hello,

So I stripped down my sterndrive leg and, pretty much I as suspected, it looks like a load of mechanical bits all covered in oil.

Here are some pictures;
The drive I'm stripping down - an OMC "Type 3" from 1977. The upper gear housing and exhaust housing have been removed here:


This is the top of the upper gear housing:


These next three show some sort of threaded stub which has snapped off at some point - not sure what it does:




This is the upper gear housing seen from the underside, showing the water pump impellor housing - this is whith the swivel plate removed:


And here's the swivel plate as seen from the bottom:


And the top:


The impellor housing is full of milky oil but the impellor itself seems to be in good condition (apart from one of the fins being bent backwards - is that normal?) Apart from the sheared stub at the very top of the upper gear housing (inside the steering gear) I haven't encountered anything obviously damaged or leaking yet, so I don't know where all this oil has come from...

Any help or advice would be very much appreciated here, as no marine mechanics within a hundred miles of me will touch this thing with a barge pole, so I'm on my own here

Thanks,

Paul

 

The threaded stub was for the original steering mechanism, not a high point of OMC engineering. I'm assuming you now have mechanical steering through the transom. Toss the impeller housing and install a new one as it comes with a water pump kit. Uh no, the impeller blades should all face the same way, you will see how when you follow the instructions in the new pump. Tip, coat the inside of the new housing and impeller with petroleum jelly. This will help the impeller survive the first startup when dry. The source of the water was likely throught the seals and orings of the swivel housing and at the top of the lower housing. You want to replace all of them. Follow the manual closely about cleaning and take care installing the new seals and position the shims properly on reassembly. Be sure to clean all the surfaces completely of corrosion and oxidation. Also be sure to use the exact oil OMC recomends in the manual or its equivalent. Plews/ Lubrimatic makes the OMC lubricants so go to their website or give them a call. Good luck!

 

Thanks for that

Is it likely that a seal higher up the driveshaft has failed?

I still have cable steering, as the exhaust housing plate has a fixed gear which slots inside the steering gear surrounding the broken stub, which is then driven by a worm-gear inside the upper housing. Nothing seems designed to bolt into the broken stub, though - I wondered if oil was somehow getting down the bolt hole (now the stub has broken off) and into the impellor housing - I've tried following my Seloc manual diagrams to see if that's possible, but I can't make it out.

Thanks for your encouragement

Paul

 

I see the cable coming from the lower housing in your picture. You did say that was a mechanical shift unit correct? This site also has parts available and offers some great exploded views of the gear cases......................


http://www.sterndrive.com/product.cfm?pcategory=10

 

It's an electric (electromagnetic) shift unit.

Somebody suggested to me that the cable might be the source of the oil leak, as the seal it goes through into the lower gear casing might have been damaged when the impellor was last installed - I'm pretty sure it's only the upper gear casing that's leaking oil, though...

Paul

 

Do you still have a dipstick attached to the screw that goes through the top of the exhaust housing cover?

 

I thought that unit looked familiar. Don't refer to it as a 400/800 unit, that confuses things. The 400/800 came after the electricshift and were a thorough disaster. What did the oil look like from the lower end? You will of course want to drain and flush that if you have not already done so. If the oil is milky you are getting water from either the prop shaft seal or the seal at the top of the lower housing. Either way you want to replace the seal at the top of the lower housing.

Being an electric shift you definitely want to use only OMC Type C gear oil top and bottom. There is no substitute or replacement regardless of what anyone says. Other oils cause shift cable and clutch/magnet issues. The wrong oil is the most frequent cause of unit failure other than water intrusion. While it can be pricey $9.00+ per quart, it is a small cost compared to replacing the outdrive. You can get most of the smaller replacement parts for this from a Sierra/Teleflex Marine parts dealer. Many parts for the electric shift are also available from Ebay. Good Luck!

 

I do...which makes me wonder what it was screwing into...I guess the dipstick must have been holding the sheered stub in place!

Until today, I thought it was a 400/800 unit - I see now from re-reading the manual that it's a Type 3 unit which, as you say, preceeded the 400/800 units - sorry about that...

The oil from the bottom end looked fine - a sort of deep blue colour. The oil from the top end was a sort of milky green with the consistency (and appearance) of paint. (I've just noticed that you can see the oil from the upper gearcase housing in the picture with the housing in the green bucket/box above)

Thanks again,

Paul

p.s.

Here's a picture of the exhaust housing with the static gear which makes the steering work:


And my avant garde configuration impellor:

 

This gentleman is another great source for knowledge and parts. I have used his experience to great advantage over the years and he still has a large selection of parts available. He was a OMC dealer when the company went belly up and still has a large inventory. Fortunately he was on the verge of retirement when OMC collapsed.

wwessler@astound.net

 

Hello,

thanks for that.

After some persuasion, I managed to remove the bearing housing from upper gear case:



There's oil everywhere, which is what I expected, but I can't see how the oil is getting into the impeller housing... Just for completeness, here's the upper gear casing now that the bearing housing has been removed:



Hopefully it's just the o-rings that have failed but is there possibly something inside the bearing housing that might have failed?

As always, thanks for your help with this

Paul

p.s. I can't get the drive gear (the ball-tooth gear) to turn by hand - should it? It turns about a degree or two and then stops - I haven't tried forcing it, but I would have thought that, with the bearing housing now removed, it should turn pretty freely...