Gimbal bearing - replace or not?

PRW

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Oct 22, 2009
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Kind of a new guy here. Been lurking for a long time and learning a lot from all the experts around here.

Anyway, here's my situation. I've got a 1985 Baja Sunsport 19 foot with a brand new Mercruiser 305 longblock, Mallory marine fuel injection, and mild cam.

Drive is an Alpha One.

This boat is new to me as of about 2 weeks ago.

2nd time out I developed a small hole in the U-joint bellows. Which of course trashed the drive input seal and caused massive amounts of oil to leak back into the U-joint bellows.

The boat saw maybe an hour total in the water with this water/oil issue in the bellows. I've got it all torn down now and I'm about to get everything sorted and start getting it reassembled. My concern is whether or not to replace the gimbal bearing (and u-joints) for that matter due to the contact with water. The entire scenario was so short term that there has not been any rust formation on the yoke/u-joints etc. Gimbal bearing is tight and turns smooth, same with the U-joints. I still have the style gimbal bearing that has the grease zerk which allows me to grease it.
I'm thinking that I should be able to grease the gimbal and u-joints and be fine without replacing them.
What are the thoughts on this?

I know it's one of those things I should do just because it had water in it and I have it apart but my thought process here is that it was for such a short duration of time it probably did no harm.

Thanks in advance
-Patrick
 

Thad

Lieutenant Junior Grade
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Jun 8, 2009
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1,028
Re: Gimbal bearing - replace or not?

OK, it has a new engine in it. My main question/concern would be "did they replace the bearing when they changed the engine?".

If that was all replaced, then I would not worry about replaceing now. Clean everything VERY WELL and grease. But if they did not replace those parts, given the age and uncertainty, I would replace them while I was there for a peace of mind.

EDIT: Oh yeah, welcome aboard.:D
 

hoot

Chief Petty Officer
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Sep 8, 2002
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434
Re: Gimbal bearing - replace or not?

Patrick, here is what I experienced with mine. I was on the water less than 20 minutes when I noticed blobs of grease rising up beside my outdrive. We headed in and found small cracks in the drive bellows. Pulled drive, a mess of grease and water mixture came out onto my shoes. I replaced the gimbal bearing, aligned the outdrive to motor, and only greased the u-joints. The following summer, I had the typical growling noise indicating u-joint replacement was needed. Pulled the drive again and even thought the joints felt smooth, the hardened steel surfaces under the needle bearings had flat spots. I expect that you will experience the same if you don't replace the joints too. I should have done it all with 1 pull of the drive and saved time.
 

zbnutcase

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Sep 19, 2009
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Re: Gimbal bearing - replace or not?

I always replace gimbal brg and u-joints as a matter of course when water has entered the bellows. And a mere hour would not cause 'massive' amounts of gear lube to be in bellows. You are prob ready for new input yoke as well. 'nutcase
 

Fishermark

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Oct 19, 2003
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5,617
Re: Gimbal bearing - replace or not?

Gimbal bearing is tight and turns smooth, same with the U-joints.

I am of the camp that says to not replace it if it is not broken. It isn't that difficult to replace later if necessary. Keep in mind that u-joints get wet all the time on an automobile - and they are the same u-joints. Keep an eye (and ear) on things and perhaps pull the drive again in a month or so and feel the bearing to see if it is still smooth. That would be my suggestion.
 

bruceb58

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Mar 5, 2006
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30,589
Re: Gimbal bearing - replace or not?

if the u-joints have zerk fittings. put in some more grease to force any water out that might have gotten in.

Do the same for the gimbal bearing. Put grease in through the fitting while rotating the bearing with your hand.

How long was the water in there? If more than a day, I would consider replacing them all.
 

Don S

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Re: Gimbal bearing - replace or not?

2nd time out I developed a small hole in the U-joint bellows. Which of course trashed the drive input seal and caused massive amounts of oil to leak back into the U-joint bellows.

That does't happen that quick, even in salt water.
I'm with nutcase, new everything back there, including pulling the yoke out and inspecting it. Undoubtedly it has a groove and rusty area on the bellows side that eat up the seal. But not in one hour.
 

PRW

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Oct 22, 2009
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Re: Gimbal bearing - replace or not?

Thanks for all of the responses.

I do not know if the gimbal and U-joints were replaced during the new engine install. I'm going to assume that they weren't considering the new engine only had about 5 hours on it and all the bellows are clearly not even close to being new.
At this point I will probably just bite the bullet and replace the u-joints and gimbal bearing so that I don't have to mess with any of this stuff again for a while.
 

PRW

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Oct 22, 2009
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Re: Gimbal bearing - replace or not?

Just posting a quick follow up...

Finally got everything back together and took the boat out for about 2 hours yesterday.

Ended up with new yoke/input seal. Of course fresh drive oil.
All new bellows
New shift cable
New trim limit and trim sender switches.

Ended up pumping the U-joints full of fresh grease and forced all the contaminated stuff out of them. They seemed good to go after that.
Cleaned gimbal bearing and pumped it full of fresh grease as well. It turned smooth and freely.

After a good two hours on the water I didn't notice any sort of leaks (water or oil). No strange noises from the U-joints or gimbal bearing to include while turning etc.

Looks like I'm good to go now for next season.

I really learned A LOT by doing this job myself. It was a major pain having never wrenched on a boat before but all in all I'm happy that I did it myself and would not hesitate to do it again in the future.
 

Glasgow

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Oct 19, 2010
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Re: Gimbal bearing - replace or not?

Hi, I know this is an old thread, but I'm hoping the original p/m will see this reply. what happened to you back then has just happened to me, and I'm contemplating doing what you did and clean up.

What I'm asking is now it has been over a year, have you encountered any problems with u joint and bearing?

I think if salt water got in even for just a minute..it time to replace as you never get it out, but fresh water no so much a problem. For rust to develop it needs air, moisture and metal.
 

PRW

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Joined
Oct 22, 2009
Messages
24
Re: Gimbal bearing - replace or not?

Actually the u-joints and bearings held up well. Unfortunately the outdrive self destructed this past summer. I'm planning to replace it with a new SEI drive this spring.
 
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