89 OMC Cobra Outdrive replacement options

Joined
Sep 8, 2010
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4
*Please skip down to the last paragraph if you want just the nuts and bolts.

I've been reading (and reading and...) and my little mind is about to explode with all the information I've gathered concerning this frequently advised problem. I wanted to say thank you to all the moderators and or members who have taken the time out of their day to share that extensive knowledge with us novices. Someday I hope to repay this debt to others and if anyone has any questions concerning all phases of construction please feel free to email me so that I can thank you in return by sharing some of my extensive knowledge with you (EDIT). With that being said herein lies the problem...

I have the wonderful 1989 2455 Cierra that came with an even more wonderful 89 OMC 5.8 351 and respective outdrive. My outdrive has just been pulled off and the lower unit is irrepairable. "It can't even be rebuilt because the casing(?) is bad". I was then instructed to hunt down a replacement. Unfortunately, the only mechanic within 100 miles who has any OMC knowledge is about 70 and has difficulty translating in lamen's English when it comes to a boat moron such as I. He is also short on time and simply gave me the model number and told me to find its replacement. He said to find the exact model number. However, after researching this site (and a few others), I've seen what I think are a few options but want to be sure. In short, here is my question:

I have an 89 OMC, standard rotation lower unit needing replacing. Model # is 985689. What other OMC lower units can I use that can replace and bolt up perfectly to the upper unit? My understanding is that any 1986-90 OMC 5.7/5.8 would work. However, anything with a 5.7 (chevy) ( model # 987797)has a different model # and I was instructed to get the exact model #. I've even read on these posts that an 87-90 460 would work?! Please enlighten me with which lower units or even complete outdrives I could find to replace this bad lower unit I have. Remember, I'm a little slow so little, lamens'-termed words work great.

Thanks a million,

Jake & the gang
 
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Bondo

Moderator
Staff member
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Apr 17, 2002
Messages
71,258
Re: 89 OMC Cobra Outdrive replacement options

Ayuh,... Welcome Aboard Jake,...
It sounds like you've got a Cobra outdrive,.. Hopefully not a King Cobra...
If it is a Cobra, there's some mix 'n matchin' capabilities in it,+ possibly Used parts for it...
If it's a King Cobra, ya might be in Really Deep Doo...
If it's a Cobra, there's an aftermaket "Kit" that'll allow boltin' on a Merc Alpha...

Good News is, the Stringer drives died a couple years Before your boat was built...
 

Gary H NC

Fleet Admiral
Joined
Dec 1, 2005
Messages
8,972
Re: 89 OMC Cobra Outdrive replacement options

Being an 89 i doubt it is King Cobra.If i am thinking right they were not made yet.

Any Cobra lower from a V-8 powered boat(GM based or Ford) should work fine.
86 through about 92 or so.
 

howlnmad

Petty Officer 2nd Class
Joined
Jul 29, 2009
Messages
178
Re: 89 OMC Cobra Outdrive replacement options

yeah, it's the upper half that makes the difference. Lowers are available (used and rebuilt), you just need to do some searching. There is a site, sterndrive.info. something that carries a bunch of OMC parts and drives. Sorry I can't post the exact site but I'm computer sturpid. Good luck.

Bill
 
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Sep 8, 2010
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4
Re: 89 OMC Cobra Outdrive replacement options

Wow- thanks for the quick responses. Sorry I left out a bit of info. While the outdrive has proven to be a "royal" pain in my butt it is not in fact a King. That makes sense about the upper being the significant one in regards to gear ratio and that many can post up to it. Just want to make sure because I'll be hunting this down on Ebay/CL over the next couple of days and want to make sure I get the right part.

One other concern I had if allowed is the culprit (from what I understand) that started this outdrive path of destruction. On former posts and links I read great articles on the cable linkage being a significant factor in causing outdrive problems. Especially when it is difficult to shift as mine is. My ESA is new and helped me be able to shift from forward to reverse but it is still difficult to shift at all. Not like the recommended 1 or 2 finger(s) needed to be able to shift. The cable linkage is red indicating I guess that it has been updated via recall. Do you think this may just need some fine tuning or can it be another significant problem. Or is it possible that sometimes these things just never can get fixed quite right or at least reasonably by financial terms. I've read the article on proper adjustment and will give this copy to my mechanic to make sure it gets done right. Just didn't want to waste his time and my money if it could be something else. That's it and thanks for all the help.

Jake & crew
 

Gary H NC

Fleet Admiral
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8,972
Re: 89 OMC Cobra Outdrive replacement options

I would pull the complete drive.You need to check the U-joints and all anyway if you have not done so recently.
You can remove the 4 bolts holding the upper cover on (where the dipstick is) and see what the upper gears look like and then flush it all out to get any metal shavings out.

Stiff shifting is most likely the lower shift cable is shot.
The cables are about 100 bucks and you need the OEM service manual to get the adjustments correct when you install the new cable.

Great price,
http://cgi.ebay.com/ebaymotors/1989...30467985017QQptZMotorsQ5fManualsQ5fLiterature


I know this seller and he can verify what manual is for your drive,

http://cgi.ebay.com/ebaymotors/1989...20615956598QQptZMotorsQ5fManualsQ5fLiterature
 

LAC_STS

Master Chief Petty Officer
Joined
Jul 1, 2010
Messages
895
Re: 89 OMC Cobra Outdrive replacement options

Is that manual in the first eBay link just for the sterndrives?

I have the manual in the second like and it has a section in it for the drive. Is the manual in the first link all about drives of something?
 

Gary H NC

Fleet Admiral
Joined
Dec 1, 2005
Messages
8,972
Re: 89 OMC Cobra Outdrive replacement options

They both cover the engines too.3.0 up to 5.8

Either one should have the cable install and adjustment info with pictures.
They are great manuals.
 
Joined
Sep 8, 2010
Messages
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Re: 89 OMC Cobra Outdrive replacement options

Awesome, and thanks for all the good and accurate info. This helps me immensely in tracking down what I need to get her fixed. Thanks for all who contributed and took the time out to help an ailing but fellow cap'n.

Jake & crew
 

4Winns2

Petty Officer 1st Class
Joined
Nov 2, 2006
Messages
327
Re: 89 OMC Cobra Outdrive replacement options

I am a little lost on whether the drive is fried and you're looking for a replacement or you're just looking to flip out the lower shift cable and fix the present drive. In any event, I can offer that I flipped the lower shift cable on my 90' 4.3 OMC this spring.

I used the directions from the OMC manual download that is stuck to this forum. I'm pretty good with a wrench but I had to study and study the directions to get it right. In the end, it wasn't all that bad and she has been shifting like butter all season. If you're not going to do get it done, plan on spending $400-500.

BTW: If the gears should ever fry in that drive, it's a $2,500.00+ SEI drive for me. (I have to stop now, I have a suspicion that my boat is telepathic and has the ability to know what I write on these forums. She is a sensitive sort.)
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: 89 OMC Cobra Outdrive replacement options

Being an 89 i doubt it is King Cobra.If i am thinking right they were not made yet.
"KING" (dog) Cobras were made from 87-89 in the Dog-clutch. They were "bigger", had their own (some) unique parts, held 108oz of oil and were ONLY bolted to the 460.

When OMC came out with the Interim (Pre-SX) drives, they started calling other drives "King" Cobra too....


You do not want to go near the KING, Dog-clutch drive. They're more rare than all the others.....some internal parts are not available any more. (unless you're into Midnight Boat Parts or wrecking yard perusing!!)


If you need a "lower" and it is internally damaged, since the oil is common to the whole drive, you should replace the entire drive(or at least rebuild the upper) if the lower had "metal" in it....


Good luck!

Also, you should edit out your email address in your first post.

The SPAM-BOTS automatically search forums just like this for addresses to "SPAM"


Regards,


Rick
 
Joined
Sep 8, 2010
Messages
4
Re: 89 OMC Cobra Outdrive replacement options

Thanks 4winns and Rick. My lower is fried but I know that it was probably attributed to bad cable. I will have the lower cable replaced when I have the new lower drive put on. I'll post back and let everyone know how it goes. Thanks again for all the quick and great advice! I will also edit that email- thanks Rick.

Jake & crew
 

MRS

Commander
Joined
Jul 10, 2005
Messages
2,580
Re: 89 OMC Cobra Outdrive replacement options

How long have you owned the boat and who has worked on it before?
 
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