omc cobra 5.0 having trouble re-installing stern drive

rowlex

Petty Officer 2nd Class
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May 10, 2007
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hey guys i am trying to re-install the outdrive on my bayliner. I dont have a hoist but i have 2 guys helping me lift it into place we have only been able to get it partially in.

we have wiggled it a lot trying to get it back on but i need some tips or something.

here is a pic..this is about as far as we can get it to go in.

acf58da1f78a.jpeg
 

gcboat

Lieutenant Commander
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May 29, 2007
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1,822
Re: omc cobra 5.0 having trouble re-installing stern drive

One thing comes to mind is the amount of grease you put on the shaft. Too much and it just won't go in no matter what. Called hydraulic lock - you can't compress the grease. Take it back out and apply just enough for it to slide nice and easy. :D
 

sea wolf

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Apr 3, 2002
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1,219
Re: omc cobra 5.0 having trouble re-installing stern drive

One word, alignment. If it's not correct you will fight & fight with that lower unit & it still won't go in. Get an alignment tool, & save your back muscles. Once you have it lined up correctly it will slide right in.
 

evilratgirl

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Apr 18, 2007
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Re: omc cobra 5.0 having trouble re-installing stern drive

Have to agree with an alignment being critical to get the drive in properly.

When I do my drive, I use an A frame ladder and hang the drive from it. I have to do it alone and having it hang rather then muscleing it.
 

Gary H NC

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Re: omc cobra 5.0 having trouble re-installing stern drive

Are you turning the shaft to get the splines to line up?Other than that the engine alignment is critical.Also look in the hole and make sure the gimbal bearing is centered..
 

Dakota47

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May 22, 2007
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Re: omc cobra 5.0 having trouble re-installing stern drive

I think the shifter need to be in Forward to install the outdrive. i may be wrong as i have a omc too
 

rowlex

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Re: omc cobra 5.0 having trouble re-installing stern drive

ive just learned about the engine alignment tool/requirement, its weird I am fairly certain it is not lined up because of some measuring I have done, but the drive came off so easily and I didn't change anything but I guess that doesn't matter.

With any luck I have found someone in my area that has the engine alignment tool but it is for a mercruiser(i think he might let me borrow it). From what I have read the mercruiser alignment tool can be used on the OMC cobra's to, is that correct?

Thanks for your help! I did try rotating the shaft to get it in but i did that at the upper driveshaft not the prop shaft. I also didn't until my last attempt have it in forward gear, but even after i put it into forward our attempts were futile.
 

fourwinnsdook

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Jun 12, 2007
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Re: omc cobra 5.0 having trouble re-installing stern drive

Looks like you are having the same trouble as me. Mine will not go past the rubber boot. Looks like you are at the same place.
 

rowlex

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Re: omc cobra 5.0 having trouble re-installing stern drive

Looks like you are having the same trouble as me. Mine will not go past the rubber boot. Looks like you are at the same place.

Fun stuff, I just got done replacing the prop shaft (my g/f ran the boat aground) spent 8 hours replacing it that day to find out we cant get the dang outdrive back on!! Very frustrating. How are you resolving the problem?
 

fourwinnsdook

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Re: omc cobra 5.0 having trouble re-installing stern drive

From what i read in my post if you put grease or if anyone else has ever put grease on the rubber bellow to slide the u-joint through the rubber will swell not allowing the u-joint to slide back in. That's my problem, i can tell because i can see the bellow wanting to pull away from it's seat when i'm pushing on it. It's also starting to bugger up the bellow. I'm going to buy a new bellow ($65.00) froma local marina and see if that does it. Can't hurt to replace it i guess. The reason i say looks like the same problem as mine is because you'rs is stuck at the same point. It's not your splines because your shaft isn't even touching them yet.
 

rowlex

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Re: omc cobra 5.0 having trouble re-installing stern drive

very interesting thanks for the info!

how long till you will know if it was your problem??

there is grease on that part of the bellow on my boat... and the carrier bearing +engine look to be very well lined up. I even stuck my old prop shaft in the hole and it went in just fine.

thanks don lol :)
 

fourwinnsdook

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Re: omc cobra 5.0 having trouble re-installing stern drive

i am leaving my office right now, and going home to see if i can fix it. i will post with progress tomorrow. i have an alignement tool, that may be your problem, but it doesn't even look like you are through the rubber yet.
 

bruceb58

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Re: omc cobra 5.0 having trouble re-installing stern drive

I think the shifter need to be in Forward to install the outdrive. i may be wrong as i have a omc too

That is wrong...it needs to be in neutral.

Stick a screwdriver in the u-joints and rotate them until the splines line up. This of course assumes your alignment of the gimbal bearing is good enough to allow the shaft to engage into the coupler.
 

Gary H NC

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Re: omc cobra 5.0 having trouble re-installing stern drive

I really think you guys are not getting the drive shaft straight,The u-joints need to be held level and not let them sag.Hard to explain but thats why they won't go thru the bellows. Kind of like pulling the drive shaft torward the back of the boat to keep them straight and centered...
I had my cobra off many times and never had that problem.Maybe i was just lucky...
 

Rob454

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Oct 9, 2005
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508
Re: omc cobra 5.0 having trouble re-installing stern drive

You need to place the tip of the driveshaft in the center bearing then start sliding it in. I usually use a long thin screwdriver due to my large fingers.
Also make sure that the bearing is aligned. if its not aligned youll never get it back in
Rob
 

rowlex

Petty Officer 2nd Class
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May 10, 2007
Messages
110
Re: omc cobra 5.0 having trouble re-installing stern drive

You need to place the tip of the driveshaft in the center bearing then start sliding it in. I usually use a long thin screwdriver due to my large fingers.
Also make sure that the bearing is aligned. if its not aligned youll never get it back in
Rob

doesnt the carrier bearing cause a problem here(as far as using a screrwdriver)?? I dont know we tried wigling it and everything. to no avail it wouldnt go any further then where the picture shows..

Is it possible to move/dislodge the carrier bearing by just pulling the outdrive off?? There was absolutly no rust on the drive shaft, it popped right out. it looks perfect. Everything appears lined up..
 

javsam

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Aug 24, 2005
Messages
421
Re: omc cobra 5.0 having trouble re-installing stern drive

on my cobra 4.3 I also found that the drive had also air locked and would not go past the u-joint swivel. the bellows was original oem and seemed to be part of the problem by having a tight fit around u joint swivel.Alignment was perfect as I had checked this with an alignment bar.the drive finally went in by turning the prop by hand with the drive in gear.once the drive hit the bell crank it would pop the drive into neutral. the next time I took the drive off, I installed new bellows and didnt have any problem because the bellows was a larger inside diameter and didnt make a tight seal around the u-joint swivel.The drive slide in,nice and easy.
 

rowlex

Petty Officer 2nd Class
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Re: omc cobra 5.0 having trouble re-installing stern drive

wow....that bellows/seal stuff could be my problem i guess.

Im going to get a pair of calipers and hopefully measure it to see if thats the culprit!
 

sea wolf

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1,219
Re: omc cobra 5.0 having trouble re-installing stern drive

All Cobra bellows were redesigned with a larger diamater so if you have a new one that shouldn't be the problem. If u have the shaft lined up correctly & it still won't go, then I'm telling you that you must line it up using the tool. I have a Cobra, so I know what the story is. OMC's are notorious for this, & it is an exercise in futility trying to install a cobra if the alignment isn't correct. Otherwise, you are wasting your time. And by the way, the drive must be in neutral.
 
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