OMC 5.8L 1989 Cobra SternDrive Broke?

[garfieldreturns]

Anyone that has experience on OMC Sterndrives, that could give me some suggestions of where to start looking for the problem to fix would be muchly appreciated.

I trailered the boat down to palm beach florida, changed the gear oil before I left.

Used it for 4 days reverse, forward, fast, slow, etc no problems.
On day 5, was going about 23mph, when heard sound like I had hit something. I stopped checked proceeded as seen or heard no problems.

Pulled up to dock 1 mile away, discovered I had no reverse, and when tried to put in reverse shift was very hard to move.
Forward still worked, decided better take the boat to trailer (20 miles away up intercoastal in case something went wrong with reverse.
Drove 23 mph, and idle no issues, no sounds to trailer.
loaded on trailer, tilted motor to trailer boat to where we were staying.

Put back in water, lowered sterndrive back in water.
Immedaite steading clunking noise when shifted in forward.
I went about 600 ft away from dock, put in neutral, still saem noise.
turned off engine, then engine would not start like it was jammed in gear, could see starter was drawing lots of current but engine would not turn over to get back to shore.
Had to pay $250 seatow to get back to the 600ft of shore to put back on trailer.

Anyone have any idea where to start to locate problem. We are back now in upstate South Carolina. My expereince last year is that there is no really good OMC mechanics around here. Because mercruiser flooded the carolinas market years ago, I have been told.

I have seen the price of both an upper and lower rebuilt unit..$3200 which is about the cost of the 22' bayliner sunbridge 1989, 351 Ford Engine I have.

I have mechanical and electrial experience, although in commerical trucks and heavy duty, automotive only.

Any suggestions of where I should be looking at, to see the extent of the problem would be appreciated.

I want to go off the coats of SC this spring, so I want to make sure I dont have any future outdrive problems again.

Thanks Dennis

 

[Bondo]

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Anyone have any idea where to start to locate problem. We are back now in upstate South Carolina. My expereince last year is that there is no really good OMC mechanics around here. Because mercruiser flooded the carolinas market years ago, I have been told.

Ayuh,...
I'd sooner believe that,..
That's probably more so because OMC has been Out of Business for over 10 Years now...

As for finding your Problem,....
Drain the outdrive,+ Look for contaminants in the oil....
Pull the Outdrive Off,+ try to turn the motor over, See if it's the Motor, or the Drive that's bound up....

Proceed accordingly, as to the clues you find....

 

[a70eliminator]

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Yep your just 6 nuts away from knowing it's fate.

 

[garfieldreturns]

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Re: OMC 5.8L 1989 Combra SternDrive Broke?

I have pulled the assembly unit off.
Engine starts to problems now.
Pulled drain plug at bottom of lowere unit.
Metal 1/4 size chunks, even the magnetic pole has broke off drain plug
gear oil, mixed with water contaminated thoughout
ujoint into motor in good shape. but gear oil lots mixed with water in bellows between gibble and upper unit.
Gear shift lever seems to be fine, shifts easy, not worn

Now where should I start? Got that feeling the lower unit is in very bad shape, just hope it aint the top also.

 

[Don S]

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Re: OMC 5.8L 1989 Combra SternDrive Broke?

The gears in the lower unit is where the drive shifts. Sounds like you need to be looking for a new drive. The gear teeth are probably broken and has the lower locked up. They probably went bad because of the water The upper gear case also shares that metal contaminated oil with the lower and is probably as bad as the lower.

 

[a70eliminator]

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Re: OMC 5.8L 1989 Combra SternDrive Broke?

I've not been there yet, knock knock
but I would definately disassemble the whole works
Get manual you'll need it.
Take lots of digital photos they can be very helpfull
in the end you'll know how evrything works and know the job was done right

Or you could just buy a rebuilt unit but still you have to find out what all is wiped out, you may find the upper unit to be the offender wiping out lower with it, by realizing you had a problem and limping back to dock may have saved it some?

 

[Don S]

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Re: OMC 5.8L 1989 Combra SternDrive Broke?

You can NOT rebuild a Cobra drive without a lot of expensive, special tools needed to position the gears properly.

 

[Bondo]

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Now where should I start? Got that feeling the lower unit is in very bad shape, just hope it aint the top also.

Ayuh,...

I'd think you probably should start by finding a Whole New Outdrive....

I doubt there'll be much Salvage in your's,... Other than possibly the Cases...

 

[garfieldreturns]

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Re: OMC 5.8L 1989 Combra SternDrive Broke?

Ok, I trying to split the top unit from the lower unit.
I have removed all bolts, and can wiggle and see 1/4 inch gap, whats still holding it together.
I did manage to get it turning now without binding.
I think the metal peices in the bottom drain plug juammed the gears there, they have since been drained out.

I am going to get a manual for sure, I just want to see if the top unit it shot, if metal in it. I removed top cover plate on top unit, is full of oil mixed with water. Oil should still not be there since I pulled drain plug on bottom, unless lower unit is full of metal peices preventing drainage?

Still anyone have an idea how to get loweer unit from upper unit?

 

[garfieldreturns]

Re: OMC 5.8L 1989 Cobra SternDrive Broke?

Thanks Don for the info,
Yes, I agree with you on it if the gear sets are shot. dial gauge, runout, etc...like rebuilding axle. I do plan on taking boat this year from palm beach to freeport bahamas 86 miles. So this has to be done right.

 

[garfieldreturns]

Re: OMC 5.8L 1989 Cobra SternDrive Broke?

Everyone has their own opionions on the best outdrive around.
But, I did talk to some oldtimers in plam beach at a boat shop.
They said that the omc is indestructable.
I bought this boat last summer from a guy on ebay, who never looked after it.
I have replaced fuse/wiring system. Serviced engine with all good stuff.
lights, etc...still got lots to do.
But, I should have torn apart outdrive also in retrospect. I changed gear oil 2x now, but it was probably neglected.
I cant see gears going bad if it is serviced and built properly.
I am leary about buying used, unless from someone with good rep and has looked at gears, tested for leaks, etc.

Still trying to remove upper from lower unit, info I got says orings only holding it together, since I removed all the bolts..... ?????

 

[HT32BSX115]

Re: OMC 5.8L 1989 Cobra SternDrive Broke?

But, I did talk to some oldtimers in plam beach at a boat shop.
They said that the omc is indestructable.

Well, It looks like they may be mistaken.

You're really wasting your time attempting to rebuild the drive. Your best bet would be to just find another one and replace it. You'll want another "dog-clutch" 1.41:1 drive to get a drive that is similar to the one you have.

You could even use a 1.43:1 drive. (460 87-89 King Cobra model)

Regards,

Rick

 

[Don S]

Re: OMC 5.8L 1989 Cobra SternDrive Broke?

The Cobra drives weren't that bad a drive, but there is becoming a problem of finding techs capable of actually rebuilding them. Don't forget, OMC has been out of buisness for over 10 years now. No more OEM parts, tech training, or factory support. Just aftermarket parts and a dwindling number of people to fix them.
The only thing there isn't a lack of is people trying to get rid of OMC's and not offering to tell their buyer all the facts.

 

[a70eliminator]

Re: OMC 5.8L 1989 Cobra SternDrive Broke?

Did you remove the screw under the trim tab? That and the 4 bolts thats it, book says to wiggle back and forth and pull it off the o-rings. Then you'll have rotate the shift rod 90degrees to clear the exhaust opening, says the manual.

 

[garfieldreturns]

Re: OMC 5.8L 1989 Cobra SternDrive Broke?

Well I got the lower and upper units apart. took some wiggling side to side, found some info how to do on another site.
1" Mussels growing inside everywhere, water couplers melted, etc. This guy that owned this before must have left the boat in the ocean for a year?
The lower appears to have never been apart, o-rings are shot shaft from lower unit.
water jacket housing was on for good. corroded on to lower unit. crow bar, and hammer and cold chisel, still it got broke...so much for it wiggling it side to side like it says on an manula I found (water jacket) ...not after 20 years anyway.. HA HA well my first $38 spent. If I rebuild the bottom unit.

If what I have seen so far is any indication...the lower unit should just be replaced, everything is probable seized or destroyed. Its has been abused anyway as it has chunks missing of skeg at bottom as well as skeg is bent. I replaced the prop, as the owner had a bent up old one.

Top unit appears ok, no chips on gears, or metal, but I will check to make sure.

Anyone know of wherwe I can get a 985689 model lower good price, or complete unit it would be appreciated.

thanks for the info e70 eliminator...

 

[garfieldreturns]

Update: OMC 5.8L 1989 Cobra SternDrive Broke?

Update: OMC 5.8L 1989 Cobra SternDrive Broke?

We I have discovered that the upper unit has been leaking oil as lots of ger oil was in bellows (where u-joint goes on upper unit mixed with water.

So the top unit would have to be resealed for sure. I got an orginal 1989 omc cobra stern drive manual $50, which is very detailed on everything.
To rebuild both units looks costly just for the tools needed, if u can even get all of them anymore.

Also I have checked out the price of the tools to fix this thing, they are nuts for a one time use. The gear set just for the bottom is around $450-$700 and that does nto include all teh seals, bearings.

I have looked around and there are complete used untis from $950 to $2000 but never been presure tested, or rebuilt/resealed.

I am not sure what to do, I have even looked at changing all over to pentaq/volva or mercruiser, but then will have to change everything.

What do the experts say is the best way to proceed to get the best value for your buck, and not have to hopefully go through this nightmare agiain.

Thanks in advance.

 

[wildgame4me]

Re: OMC 5.8L 1989 Cobra SternDrive Broke?

I have a Bayliner Cerria 1989 omc 5.8L (stern drive serial #T0654651 Model # 985689) same as yours.
I experienced the exact same problem on May 7th 2010 Lower unit froze and motor would not crank. I payed 220 dollars for the tow in.
I later drained lower unit oil and found metal and the magnet broke off. I removed sterndrive and seperated the upper from the lower unit. From what I 've seen only the lower unit is bad. So I guess I am going to purchase a rebuilt lower unit. Your message is exactly what happened to me.

Can you let me know how the repair went? Is there other damage that happened because the lower unit froze up?

I will inform you with my results. my e-mail address is
wildgame4me@yahoo.com Thanks

 

[bruceb58]

Re: OMC 5.8L 1989 Cobra SternDrive Broke?

Since the Op hasn't logged in since Feb of 09, I doubt he is going to see your new post a year later.