Removed the Wrong Screw

repeater

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Oct 30, 2021
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Hello, I'm new here, and new to boating.

I have a 1993 OMC 5.0L Cobra stern drive. In the process of draining water from the outdrive, I think I removed a screw "that shall not be removed" on the port side of the drive. As I was unscrewing it, something sounded like it fell internally, inside the drive. I'm sure it's not a good thing. Can someone help me understand what I've done? Thanks!
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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You have turned a 2 minute job into a 2 week repair

Pull the drive

Get a factory repair manual and a seal kit

You now get to pull the whole lower unit apart to rebuild it
 

kenny nunez

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Jun 20, 2017
Messages
3,056
Remove the drive like Scott said then stand it upside down, you should be able to fish the piece of metal that the screw went into and reinstall the screw holding the plate in place. Worse case scenario with a service manual separate the upper from the lower if you cannot fish out the plate with a piece of wire, it is probably stainless but try a magnet anyway.
Also a good time to grease the joints, gimbal bearing and check the alignment if you have the aligning tool.
 

repeater

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Thanks guys for the ideas so far. I appreciate them.

Related to all of this -- I put the drive to its lowest position and immediately noticed water coming out of the hole that I removed the "wrong" screw from. That was unexpected, since I had removed 3 other drain screws several days before. As it rests in the lowest position now, there is still water sitting in a small pool below the opening. Why was / is there still water in the drive? Makes me wonder where else water is still sitting. I think I might pour antifreeze into the hose leading from the drive to the engine....
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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pull the drive
split the drive
fix the drive
 

Lou C

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OK the reason why you see water coming out of that hole and will always see water coming out of that hole, is that behind it is the water passage that leads from the impeller to the transom mount. So in order to fix this problem you will need to pull the drive and see if you can fish out the retainer piece that holds the screw in place. The raw water impeller on a Cobra (easiest to service ever designed) is just above where that hole is, in the upper gear housing.
 

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Bob Sander

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Nov 29, 2021
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115
It's the nut which holds the screw in place. It's a pain in the azz to get. You have to remove the stern drive and flip it on its side and it'll fall out onto ground easy-peazy.

To reinstall simply place the nut on a long screw driver with a bit of double sided tape holding it to the driver, gently insert into place and screw the screw down into it.

Lastly... never undo it again :)
 

88 Capri (2022 SOTY)

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The only reason I realized the do not remove screw is I when I had my drive off and could see the anxiety it would cause by mistakingly doing so.
 

repeater

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Oct 30, 2021
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Thanks everyone for the info. I now know what is involved - including to <not> do that again. Now to getting it back together...
 

Bob Sander

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Nov 29, 2021
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The only reason I realized the do not remove screw is I when I had my drive off and could see the anxiety it would cause by mistakingly doing so.
I removed mine so I could paint the drive while I had it on the bench. Figured it would faster and easier than masking the screw head.

I was wrong. What a pain in the azz to get it back in.
 

88 Capri (2022 SOTY)

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If I'm not mistaken I think there was a cobra emblem over it originally but not positive. I have seen drivers with the emblems on both sides but not sure if that is an original setup.
 

Bondo

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Ayuh,...... If I had a OMC Cobra,....... :rolleyes:

I'd die-grind the slot off that screw, so nobody Could remove that screw, ever again,.....
 

Lou C

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Or install it with Red Loctite lol. When this gets removed by mistake they just fall in the water passage that leads from the impeller housing. So if you pull the drive you just tilt it so the retaining plate falls out. No biggie. Still running my original Cobra 33 years old has needed next to no repairs. Picked up a nice fresh water unit that I will have rebuilt as a spare. As long as I can get parts I’m sticking with these. I assembled an inventory of Cobra spares in my garage it’s starting to look like the shop I used to take it to when I first got into boating. There are a lot of good freshwater parts on eBay and compared to Volvo they are much cheaper like 1/3 as much.
 

Lou C

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Well Bruce I guess our experience was different then. Maybe because my former mechanics (since retired) were able to set it up perfectly right after I bought this boat in 2002. They set up the shift linkage, replaced some leaky trim lines and a bearing carrier that caused a leak. After that it has had NO repairs, not one, in over 15 years. All I've done is normal maintenance, chaning gear oil, pulling the drive, bellows changed, impeller done every 3 seasons etc. And this boat has sat in salt water for 6 months each season, for all that time.
I taught myself to do it because I knew they were retiring and bought the 3 OMC tools to make the adjustment perfect. I didn't even have to change the shift cable. At this point for my next boat I would not buy a modern I/O of either make. They are as complex as outboards without any of the advantages of the older I/Os (simple engines, inexpensive parts) and still have all the designed disadvantages of I/Os. My brother has one, I tried to convince him to wait for an outboard boat but he came across a nearly new 2020 Chapparal 21' with the Merc 4.5 200 hp V6. Starts and runs great like a modern car, but anything beyond oil/filter change, fuel filter change and draining the water via the quick drain is not easy at all. In the manual Merc says you should grease the driveshaft splines (they have grease fittings on the coupler) and the steering cable. Well I looked down there, the only way that's happening is if the entire rear cushion is removed and someone hangs upside down to reach down there. I can't imagine what changing the starter or God forbid the steering actuator would be like. I know bigger I/O boats sometimes have better access but the smaller ones do not.
 

88 Capri (2022 SOTY)

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Or install it with Red Loctite lol. When this gets removed by mistake they just fall in the water passage that leads from the impeller housing. So if you pull the drive you just tilt it so the retaining plate falls out. No biggie. Still running my original Cobra 33 years old has needed next to no repairs. Picked up a nice fresh water unit that I will have rebuilt as a spare. As long as I can get parts I’m sticking with these. I assembled an inventory of Cobra spares in my garage it’s starting to look like the shop I used to take it to when I first got into boating. There are a lot of good freshwater parts on eBay and compared to Volvo they are much cheaper like 1/3 as much.

I'd like to do the same thing as you have described with parts and extra unit. To me it's like back in the day when all I had were old vehicles and always hoarded extra parts.
 

bruceb58

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Well Bruce I guess our experience was different then. Maybe because my former mechanics (since retired) were able to set it up perfectly right after I bought this boat in 2002. They set up the shift linkage, replaced some leaky trim lines and a bearing carrier that caused a leak. After that it has had NO repairs, not one, in over 15 years. All I've done is normal maintenance, chaning gear oil, pulling the drive, bellows changed, impeller done every 3 seasons etc. And this boat has sat in salt water for 6 months each season, for all that time.
I taught myself to do it because I knew they were retiring and bought the 3 OMC tools to make the adjustment perfect. I didn't even have to change the shift cable. At this point for my next boat I would not buy a modern I/O of either make. They are as complex as outboards without any of the advantages of the older I/Os (simple engines, inexpensive parts) and still have all the designed disadvantages of I/Os. My brother has one, I tried to convince him to wait for an outboard boat but he came across a nearly new 2020 Chapparal 21' with the Merc 4.5 200 hp V6. Starts and runs great like a modern car, but anything beyond oil/filter change, fuel filter change and draining the water via the quick drain is not easy at all. In the manual Merc says you should grease the driveshaft splines (they have grease fittings on the coupler) and the steering cable. Well I looked down there, the only way that's happening is if the entire rear cushion is removed and someone hangs upside down to reach down there. I can't imagine what changing the starter or God forbid the steering actuator would be like. I know bigger I/O boats sometimes have better access but the smaller ones do not.
Sorry...writing was on the wall when I was finding NLA parts for my Cobra...this was in 2001 for an 88 boat.

I did ALL the work on my OMC including using the factory tools to set up the shift cable which I had to replace 3 different times.(drive always stored down) When I bought my boat, the dog clutches were worn out because of a bad shift cable. Thankfully, OMC was still in business then and they were replaced under warranty.

I do not want my garage filled up with used NLA parts I have to scour around on eBay to find and store.

On my current Mercruiser powered boat, those zerks on the drive shaft you are complaining about are in plain sight. Of course Volvo and OMC didn't have them and you can accomplish the same thing by pulling the drive. You don't really need to use those zerks on the Merc if you just want to do it the old fashioned way like Volvo and OMC does.
 
Last edited:

88 Capri (2022 SOTY)

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Sorry...writing was on the wall when I was finding NLA parts for my Cobra...this was in 2001 for an 88 boat.

I did ALL the work om my OMC including using the factory tools to set up the shift cable which I had to replace 3 different times. When I bought my boat, the dog clutches were worn out because of a bad shift cable. Thankfully, OMC was still in business then and they were replaced under warranty.

I do not want my garage filled up with used NLA parts I have to scour around on eBay to find and store.

On my current Mercruiser powered boat, those zerks on the drive shaft you are complaining about are in plain sight. Of course Volvo and OMC didn't have them and you can accomplish the same thing by pulling the drive. You don't really need to use those zerks on the Merc if you just want to do it the old fashioned way like Volvo and OMC does.
I can understand your viewpoint on searching and storing parts but you do what you have to 😉
 

bruceb58

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I can understand your viewpoint on searching and storing parts but you do what you have to
It was more than just the OMC Cobra...it was also the fact that it was a Bayliner and was tired of the crappy quality of that as well. The two combined was just too much to keep it any longer
 

88 Capri (2022 SOTY)

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Bayliners crappy quality is an understatement!
That is why I had to gut the boat and rebuild it but newer boat prices are ridiculous and this was the only way I'd have a boat.
Maybe one day I can have a newer one but not having a payment is nice lol.
 
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