what does cracked bellows cause? safe to run?

fireicyhott

Seaman Apprentice
Joined
Jul 30, 2007
Messages
43
Hi all,

I have a 1990 Four Winns 225 Sundowner with a 5.8L OMC/Cobra drive. I noticed while working on my outdrive tonight with it all the way up that my black rubber bellows are definitely cracked and have holes in them.

What will happen if I run the boat with this cracked bellow? I see where it attaches to the transom side but can't quite see how it attaches to the drive. How does it attach and is it hard to replace? Any suggestions on where to get this part?

Thanks,

Jeff
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: what does cracked bellows cause? safe to run?

If it's the ujoint bellows, your gimbal bearing, ujoints, and probably the outdrive will all have water in them. Water is not a good lubricant. and starts destroying parts in short order.
If it's the exhaust bellows, they come with holes in them.
 

jmills224

Cadet
Joined
May 20, 2007
Messages
22
Re: what does cracked bellows cause? safe to run?

If its the u-joint bellow about $600 in parts. Gimbal bearing, u-joints, gear end yoke, yoke seal plus the bellow thats cracked. Thats if one of the above doesn't let go and sink your boat. Fix it asap!

~J
 

fireicyhott

Seaman Apprentice
Joined
Jul 30, 2007
Messages
43
Re: what does cracked bellows cause? safe to run?

I think it may be the exhaust bellow as it actually looks like the holes are supposed to be there.

It is the one you can see very easily with the drive tilted all the way up. Looking up underneath it is easy to see.

Is this the exhaust bellow?
 

Gary H NC

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Dec 1, 2005
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Re: what does cracked bellows cause? safe to run?

Yes,the bottom bellow is the exhaust.The aftermarket OMC bellow was designed that way for exhaust relief.
Its the larger upper bellows that need to be sealed water tight.
Usually if it fails you will get water in the bilge and ujoint and gimbal bearing damage.Sometimes it will show up in the drive oil also.
Have you drained the gear lube to check for milky or foamy oil?
Gear lube should be changed every season along with removing the drive and greasing the ujoints.
 

PowerAddict

Chief Petty Officer
Joined
Aug 8, 2007
Messages
418
Re: what does cracked bellows cause? safe to run?

I think it may be the exhaust bellow as it actually looks like the holes are supposed to be there.

It is the one you can see very easily with the drive tilted all the way up. Looking up underneath it is easy to see.

Is this the exhaust bellow?

I wish I would have differentiated the difference before i had my marine store order the parts....
 

fireicyhott

Seaman Apprentice
Joined
Jul 30, 2007
Messages
43
Re: what does cracked bellows cause? safe to run?

So now I know thanks to you guys that my lower bellows is the exhaust and is supposed to have the holes in them on my OMC.

I have not drained the gear oil to check for water, I did top it off and oil on dipstick looked very clean but I will go ahead and drain it and refill it to be on safe side.

Do you have to remove the whole from boat to grease the u joints?

Thanks,

Jeff
 

sea wolf

Lieutenant Junior Grade
Joined
Apr 3, 2002
Messages
1,219
Re: what does cracked bellows cause? safe to run?

So now I know thanks to you guys that my lower bellows is the exhaust and is supposed to have the holes in them on my OMC.

I have not drained the gear oil to check for water, I did top it off and oil on dipstick looked very clean but I will go ahead and drain it and refill it to be on safe side.

Do you have to remove the whole from boat to grease the u joints?

Thanks,

Jeff

Yes. You need a manuel. Refill it the wrong way & you can kiss your drive goodbye.
 

Gary H NC

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Dec 1, 2005
Messages
8,972
Re: what does cracked bellows cause? safe to run?

The drive will have to be removed to grease the ujoints. That may be a job for this winter if you feel the ujoint bellows are ok.
To fill a Cobra drive,remove the top dipstick plug if it has one.Then the lower drain screw as well as the middle one.Let drain.
Start filling very slowly from the bottom hole.When it comes out the middle hole screw that plug in.Keep filling very slow until it shows full on the dipstick with it just resting in the hole.Then screw in dipstick and install bottom plug.
After the first run check the level on the dip stick.
My 4.3 Cobra held exactly 64 ounces,I think yours should be the same.I know the King Cobra holds more.
You need to invest in a factory manual before removing the drive.There are some critical shift cable adjustments to be done when the drive is pulled.
 
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