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Discussion Starter #1
I have a 1988 Centurian cruiser with a 7.4L and Bravo 1 outdrive. I have noticed the past few times I have had it out it is making a squeak/bearing nose from the outdrive area. You can hear it in nuetral or in gear. The boat only has 230 hours and has a drive shower added. After searching around it looks like the gimball bearing is a common place to look for issues. Is there anywhere else I should be looking for problems?

Thank you, Todd
 

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I have a 1988 Centurian cruiser with a 7.4L and Bravo 1 outdrive. I have noticed the past few times I have had it out it is making a squeak/bearing nose from the outdrive area. You can hear it in nuetral or in gear. The boat only has 230 hours and has a drive shower added. After searching around it looks like the gimball bearing is a common place to look for issues. Is there anywhere else I should be looking for problems?

Thank you, Todd
Gimbal breaing will make a growling noise...chances are the bellows has a hole in it too...
 

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hes refering to the drive bellows,when there is a small leak it will alow water to get to the gimbal bearing and then you get what you have unless you grease the heck out of it all the time they are not sealed very well.
 

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Actually the U-joint bellows are sealed very well when they are installed correctly. Usually the gimbal bearing does growl when it is failing but it is not impossible to squeal. I would pull the drive and rotate it by hand, make sure it is completely smooth. Look for signs of water intrusion while the drive is off. If there is, replace the bellows. The bellows needs to have bellows adhesive applied to both ends to ensure a water tight seal.
 

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Discussion Starter #6
Actually the U-joint bellows are sealed very well when they are installed correctly. Usually the gimbal bearing does growl when it is failing but it is not impossible to squeal. I would pull the drive and rotate it by hand, make sure it is completely smooth. Look for signs of water intrusion while the drive is off. If there is, replace the bellows. The bellows needs to have bellows adhesive applied to both ends to ensure a water tight seal.

It is more of a growl than a squeal. I am very competent at rebuilding engines and such but am a bit weary tearing into this thing without the help of someone who has had some experience taking one apart before. I will probably start by getting a service manual. Any tips on a good place to get one?
 

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Discussion Starter #9
Finally removed the drive assembly

Hoping to get some advice from the resident experts. I finally took the outdrive off to inspect the gimbal bearing and u joints since I have a bearing noise coming from the outdrive. The drive came off easily and the bellows doesn't appear to have any holes in it. The gimbal bearing doesn't feel like it has any rough spots at all but the u joints have stiff spots in certain positions. I am also concerned with the rust on the u joints and shaft. What should I be checking for? Thanks in advance.


 

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grease 'em

Grease up and try to run the u-joints through their range of travel.
If you can get them free'd up, re-install.
If not replace 'em.
I always was pretty liberal with marine grease all over just about everything inside there.
Just be careful not to get too much on the splines where you can not get it engaged with creating a "lock" with too much pressure to get shaft in.
Most of my drives had some rust. Just depends on age, how much condensation has been there, and if bellows has ever leaked. A bad enough leak in the bellows will be letting water into boat / bilge. If you were not taking any on, you should be good. If there loooks like any weathering or cracks, may be a good time to replace that too. Kind of like being 1/2 way there already since the drive is off. Not the most fun job though. Rough squeezing a bunch of extra hands in tight spots, stretching the new one, and getting everything in place while you tighten hose clamps. If you have ever done a u-joint in an auto driveshaft, no biggie. GOOD LUCK!
 

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Hoping to get some advice from the resident experts. I finally took the outdrive off to inspect the gimbal bearing and u joints since I have a bearing noise coming from the outdrive. The drive came off easily and the bellows doesn't appear to have any holes in it. The gimbal bearing doesn't feel like it has any rough spots at all but the u joints have stiff spots in certain positions. I am also concerned with the rust on the u joints and shaft. What should I be checking for? Thanks in advance. If the gimbal bearing is not bad you might want to check the magnets on the drain plugs for metal the ujoints will make more of a knock when you go into turns but no squeal the gimbal bearing should not turn free and may still be the problem when its under load hope this helps


If the gimbal bearing is not bad you might want to check the magnets on the drain plugs the ujoints will make a knocking noise in turns but no squeal the gimbal bearing shouldn't turn free and still might be the problem under load
 

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Discussion Starter #12
After I originally posted I discovered the squeak noise I heard was not related to the bearing grumble. The squeak was coming from worn drive belts.

Tonight I greased the u joints and feel thats where the vibration and noise is coming from. They took several pumps each before grease came out of the cap ends and the grease was really black. I tried to get the joints to loosen up but I think the damage is already done. I plan to replace both joints and the gimbal bearing since I have it apart. I may as well change the bellows as well since its all apart eventhough it appears to be in good shape. Any reason why I shouldn't mess with the bellows? It appears to be original from 1988.
 

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After I originally po sted I discovered the squeak noise I heard was not related to the bearing grumble. The squeak was coming from worn drive belts.

Tonight I greased the u joints and feel thats where the vibration and noise is coming from. They took several pumps each before grease came out of the cap ends and the grease was really black. I tried to get the joints to loosen up but I think the damage is already done. I plan to replace both joints and the gimbal bearing since I have it apart. I may as well change the bellows as well since its all apart eventhough it appears to be in good shape. Any reason why I shouldn't mess with the bellows? It appears to be original from 1988.
You can change the bellows fairly easy if you take the part that locks in the bell housing with the aluminum ring and fold it into itself.If you pull the exhaust bellows out of the way you can shove the drive bellows in from the bottom clamp the back side on the gimbal housing then unfold the other end into the bell housing it will pop right in with no problems then put the aluminum ring in and your done you can put the exhaust bellows back on or leave it off if you have through transom exhaust good luck with your prodject
 

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You can change the bellows fairly easy if you take the part that locks in the bell housing with the aluminum ring and fold it into itself.If you pull the exhaust bellows out of the way you can shove the drive bellows in from the bottom clamp the back side on the gimbal housing then unfold the other end into the bell housing it will pop right in with no problems then put the aluminum ring in and your done you can put the exhaust bellows back on or leave it off if you have through transom exhaust good luck with your prodject
This is good advice. The bellows is definitely leaking, change it. I would never re-install a drive with u-joints that don't feel perfect. If they fail it will damage a lot of expensive parts. It's off, do it now. With all the rust on the u-joint/yoke assy., I'm surprised the gimbal bearing isn't damaged. It must spin freely and feel like a new bearing.
 
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