OMC outdrive --Major problem?

[gingersruletheworld]

so I bought a boat with a OMC 120 ...year? not sure...easiest way to date it? So, the gears (worm ball gear..?) the main drive from the motor...it's stripped as is the one on the outdrive....the balls are completely worn...This is the linkage that connects engine to outdrive. What is approx price for repair? (in canada/ont)...the shaft going to the engine is loose (you can wiggle it) Should I just be looking at finding a new outdrive? this is a older boat...just started so any feedback would be great and if you need more info ...let me know...tks

 

[twostroke87]

Re: OMC outdrive --Major problem?

*sigh*

Lets start off with how much you paid for the boat? Not to be a negative nancy but OMC Stringer drives (ball gear style) were terrible when they were new, and they are even worse now that they are old, OMC came out with the Cobra outdrive in 1985, so your drive is atleast 24 going on 25 years old. Also OMC went out of business in 1994, parts are hard to come by.

Your asking how much to get this job done at a marina? Depends on if you can find one that will even work on that style. If you do, the ones around me charge atleast 300-500 to uninstall and reinstall an OMC stringer drive with a cable system, not sure how much for electric shift, if that is what you have i dunno.

Thats just to Take it off, and put it on. What they would charge to do the work you are asking, for the ball gear and the drive who knows but I'd bet they'd charge a small fortune, and chances are when all is said and done they will put it together and you with have other problems with the drive.

Bottom line, and this is flat out honesty. If you haven't invested a lot in the boat, or didn't pay a alot for the boat, cut your losses now, try and sell it junk it whatever, and search out another used boat with a Mercruiser or Volvo drive.

 

[gingersruletheworld]

Re: OMC outdrive --Major problem?

I don't have much invested but would like to keep the boat!..... I would look at putting a new to me (used) out drive on it....will the cobra drive be able to link to my older OMC engine (drive shaft, tranny etc)?

Sigh** -- I got taken on this used boat....first time buyer and I guess I'll take it as a lesson learned!

 

[Robj]

Re: OMC outdrive --Major problem?

Sigh** -- I got taken on this used boat....first time buyer and I guess I'll take it as a lesson learned!

Don't feel bad, it happens to most of us. I agree get rid of it and buy a boat with a Merc or Volvo. But even with those there ones to stay away from.

Have a great day

Rob.

 

[gingersruletheworld]

Re: OMC outdrive --Major problem?

I don't want to give up on it yet.... I am hoping I can upgrade the old stringer to a cobra drive....scrap the stringer and look for a used cobra. This must be something that can be done? I have decided that I don't want to invest in fixing the stringer if I am going to see more problems down the road. I am just hoping that a cobra will be able to be linked with the OMC 120 in the boat?

ps...what a great site for getting advice...tks to all.....

 

[Howard Sterndrive]

Re: OMC outdrive --Major problem?

easiest way to date the boat is to look at the HIN on the hull and on the registration - the last 2 digits of th hull identification number are the year.

Buying a boat in Ontario with no registration is a nightmare, btw.

I am just hoping that a cobra will be able to be linked with the OMC 120 in the boat?

no. can't be done unless you have many thousands of dollars in the budget and want to do a lot of plywood and fiberglass reconstruction of your transom.

Sounds like your entire drive system is junk, but you'll have to look at it to make that call. Intermediate bearings are shot obviously from your wobbling shaft description. The engine has to come out to repair that.
The engine should probably be compression tested, pressure tested for freeze damage, and run on the floor while it's out.
That's what I would do.
And the whole drive should probably be looked through before spending any money.
The floor, stringers and transom of the hull should be inspected while engine is out. Cut some test holes under seating to look at floatation foam.

As far as the drive goes: as with every used boat purchase you'll need to replace a water pump impeller, and You'll have to remove the drive and remove the upper from the lower to replace the impeller, so start with that and see what kind of shape the fluids you drain are in and see what the vertical w/p shaft splines look like.

If the engine checks out, and your intermediate shaft survived and the upper and lower aren't trashed, and you are very handy and have good tools, you could potentially be on the water for as little as $1500 or so.

Keep in mind, when you are all done, that boat, on a nice trailer in excellent running condition has a retail value of around $2000 in the great lakes region.
But at least you will know what you have.

 

[gingersruletheworld]

Re: OMC outdrive --Major problem?

Ouch! Well that is a kick in the nuts! Yes, I figured by the wiggle in the shaft that the bearings are shot. So, should I look for another stringer outdrive to replace the one on it or just fix what is there? I am guessing that I can get a used one cheaper than the cost of all the labour to replace the damage to this one?? If so, any help in a good spot in Ontario to find them?

my happiness in my new boat is quickly changing to dread

never even got a 10 min ride

 

[Howard Sterndrive]

Re: OMC outdrive --Major problem?

I figured by the wiggle in the shaft that the bearings are shot. So, should I look for another stringer outdrive to replace the one on it or just fix what is there?

I don't understand..

You said the shaft going to the ENGINE was wobbling.
How would another outdrive fix that?

The shaft going to the engine is in the intermediate housing, not the outdrive.

I am guessing that I can get a used one cheaper than the cost of all the labour to replace the damage to this one??

you haven't learned from the used one you just bought?

used is used. You can get lucky, but you need to know what you are looking for.
A good used 400 or 800 series outdrive, with a shift cable, pressure tested with a new water pump kit would sell for $2000 to $3000 at any reputable shop.

Find out if your engine and/or hull is any good first.
Get off the internet and go drill some holes in the floor

 

[gingersruletheworld]

Re: OMC outdrive --Major problem?

ok...so I spent some time on it....it is the intermediate housing....the bearing is gone as is the ball gear... I am going to keep pulling it apart and see what shape the rest of the shafts are in....oil levels were good and no evidence of water....My first good news so far...

 

[gingersruletheworld]

Re: OMC outdrive --Major problem?

So it's a new year and I've actually hit the water with my OMC. I got the ball gears replaced and so far so good. Any advice from experienced users of the OMC stringer drives of do's and don't? things to watch for ? etc

any advice would help

tks

 

[superbenk]

Re: OMC outdrive --Major problem?

Don't *EVER* run the motor with the drive tilted up *AT ALL* - that's how your ball gears got wrecked to begin with. That drive is meant to be all the way down when running, period. It's not like the outdrives with U-joints that allow you to tilt the drive while running. OMC Stringers trim by trimming the entire motor/outdrive assembly, not by trimming the outdrive itself.

As has been said many times throughout the forum, don't ever start the motor without water running through the outdrive or your impeller will fry (as in within seconds). Should always be either in the water or on muffs.

Be sure to inspect your transom boot often as that is a major source of leakage if it gets a hole torn in it. They wear out.

Check your tilt mechanism regularly. They have a tendency to leak easily (I'm talking about the square housing on the port side of the outdrive that tilts the outdrive up and down). There is a clutch pack in there that needs to remain oiled (30-weight gear oil). Often water will infiltrate the housing & seep up into the tilt motor & ruin it. I've read recommendations of replacing the 30w oil with marine grease because it's more durable & less susceptible to being washed out by infiltrating water. That's what I've done in mine and it seems to work well (though I've modified my clutch pack in a way I don't recommend). Keep the tilt pivot points greased regularly. There's zerks fittings under the rubber bumpers on either side of the drive.

Check & change your outdrive gear lube regularly. I do mine every year, but check it a few times during the season to make sure it's not milky or low.

 

[wire2]

Re: OMC outdrive --Major problem?

Don't *EVER* run the motor with the drive tilted up *AT ALL* - that's how your ball gears got wrecked to begin with. That drive is meant to be all the way down when running, period. It's not like the outdrives with U-joints that allow you to tilt the drive while running. OMC Stringers trim by trimming the entire motor/outdrive assembly, not by trimming the outdrive itself.
.....

That's sound advice but not always possible. There will be times that there's shallow rocks or a sandy bottom just below the hull. My dock area is only 16-18" deep, there's no choice but to tilt the drive up a bit to enter/exit. Then driving on idle to get into deeper water is fine.

Turning a corner at speed (or idle) will also "unmesh" a large portion of the ball gears on a horizontal plane, the same as tilting up does vertically. There's just no avoiding it.

The ball gears are made of manganese, a very hard and durable metal, and will take quite a bit of abuse. I changed mine only 2 times in 24 years, and that's with a hopped up 5.7 at 300+ hp.

If you still have play in the intermediate shaft, it's likely just the cup/cone bearing behind the ball gear. I'm 99% certain that it's a generic number, available from any bearing supply. You will have to check the shims after a change, to get the right clearance. There's a stack of them behind the plate (4 bolts).

A stringer does have at least one advantage over Merc/Volvo/Cobra; You can make a U turn in the boat's length. That's something I missed when I converted to Merc a couple years ago.

The ss screws holding the rubber boot on to the transom will eventually leak. Remove one or two at the bottom, then push a very small slot screwdriver into the hole at a 45? angle. If it goes in 1" or more, the transom wood is rotten.

 

[superbenk]

Re: OMC outdrive --Major problem?

Turning a corner at speed (or idle) will also "unmesh" a large portion of the ball gears on a horizontal plane, the same as tilting up does vertically. There's just no avoiding it.

That's not true. The outdrive turns on a swivel bearing between the upper & lower gear case. The upper gear case does not turn at all & should always be in square contact with the ball gears. I understand you may be in a position where running the drive all the way down isn't possible, but the fact remains that it will chew up the ball gears. It was not meant to be driven that way, period, whether it's convenient or not. If you do enough of that, you get ball gears like this (got my boat with the gears like this & had to replace them):

The ss screws holding the rubber boot on to the transom will eventually leak. Remove one or two at the bottom, then push a very small slot screwdriver into the hole at a 45? angle. If it goes in 1" or more, the transom wood is rotten.

You should always install the boot with 3M 5200 marine sealant around the lip & in each screw hole to avoid this problem. A properly sealed hull shouldn't leak, nor should screw holes.

 

[wire2]

Re: OMC outdrive --Major problem?

That's not true. The outdrive turns on a swivel bearing between the upper & lower gear case. The upper gear case does not turn at all & should always be in square contact with the ball gears. I understand you may be in a position where running the drive all the way down isn't possible, but the fact remains that it will chew up the ball gears. It was not meant to be driven that way, period, whether it's convenient or not. If you do enough of that, you get ball gears like this (got my boat with the gears like this & had to replace them):

....

SB, you are right! I was forgetting that the outdrive swivelled for steering. I'm gonna blame "oldtimer's disease" (64) )

 

[wire2]

Re: OMC outdrive --Major problem?

SB, looking at the worn ball gears in your pic, that they're painted white means they're at least 27 years old. I think that they deserve to be "put out to pasture"

 

[superbenk]

Re: OMC outdrive --Major problem?

SB, looking at the worn ball gears in your pic, that they're painted white means they're at least 27 years old. I think that they deserve to be "put out to pasture"

Ya, I agree, but I still stand by my comments. I've read of people with older OMCs than mine that have never replaced them. Regardless, he asked for best practices, so that's what I gave

#1 best practice I've learned from having an OMC Stringer... don't buy an OMC Stringer

 

[wire2]

Re: OMC outdrive --Major problem?

....


You should always install the boot with 3M 5200 marine sealant around the lip & in each screw hole to avoid this problem. A properly sealed hull shouldn't leak, nor should screw holes.

Yes, the key word here is "should".

I bought a boat new in '84, had a 5.7/800 stringer installed, and no one suggested to me to occasionally remove the boot screws to re seal them. There appeared to be clear silicone on the boot when I removed it to convert, after the transom needed to be replaced.
http://forums.iboats.com/showthread.php?t=225270

Looking through the "Boat restoration and building" threads will turn up many similar instances. Most people will reasonably expect that the factory or dealer will install and seal a drive properly, and not expect to have to re do it themselves. Until they experience failure of the seal one time.

 

[superbenk]

Re: OMC outdrive --Major problem?

Yes, the key word here is "should".

I bought a boat new in '84, had a 5.7/800 stringer installed, and no one suggested to me to occasionally remove the boot screws to re seal them. There appeared to be clear silicone on the boot when I removed it to convert, after the transom needed to be replaced.
http://forums.iboats.com/showthread.php?t=225270

Looking through the "Boat restoration and building" threads will turn up many similar instances. Most people will reasonably expect that the factory or dealer will install and seal a drive properly, and not expect to have to re do it themselves. Until they experience failure of the seal one time.

Good call. Alternatively, you can mount the boot upside down so the folds get kinked & tear a hole within the first year of use so that you just replace the boot every year

Speaking of that, if you buy the Sierra boot, the model number embossed in the rubber should be upside-down when you install the boot & the double arrow should point down, not up. It makes no sense, but I learned the hard way.

 

[bosshoff]

Re: OMC outdrive --Major problem?

How long does it take to replace the ball gears as shown in Superbenk's photo, assuming the outdrive was on a bench, seperate from the boat?

 

[superbenk]

Re: OMC outdrive --Major problem?

How long does it take to replace the ball gears as shown in Superbenk's photo, assuming the outdrive was on a bench, seperate from the boat?

Not long at all assuming you're not pulling the shaft/seals. I think technically you're supposed to pull the shaft & replace the seals, but mine were in good shape still & I didn't want to risk messing with the shims, etc. if I didn't have to.

Once you pry off the nut cover and remove the nut that holds the gear on the shaft, you'll need to pry the gear off the shaft. This can get hairy if it's corroded & you'll need to be careful. Once the old gears are off, the new ones go on, the nut is tightened down & the cap should be hammered in. That was about it for me (about 20-30 mins total actual work time).

I took a few pics of the process which you can see here:

http://picasaweb.google.com/superbenk/BallGearReplacement