Alpha one Gen 2 gimbal bearing replacement

J

JohnsonBargeMan

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Mar 31, 2013
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Two years ago I had my boat in for spring maintenance. The machenic told me that the gimbal bearing was going (because of the sound...wasn’t sounding real loud, just audible). I replaced the bearing and had the alignment done before reassembly. When turning the old bearing by hand you could feel some minor rough spots, but it turned freely by hand.

Ran the boat (like maybe only 4 time through the entire summer, what a disappointment) and continued to hear the noise. Took it apart at the beginning of the winter, and just now getting back to it. Looking at it now I noticed scarring on the... ?yoke? (Picture attached) Not sure if it was there last time or not. So, my question is, do I need to replace the yoke?

Oh, I also replaced the gear oil. I wanted to see if there were any metal shavings or water. No water. Attached is the lower plug. Some shavings, but is that normal?
 

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harringtondav

harringtondav

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A bad gimbal bearing will make noise when you make a turn under power. It will be noticeable.

I noticed similar marks on my coupler yoke. The consensus on the forum was that since the gimbal bearing surface is good, remove the O rings and shine it up with a narrow strip of sandpaper. I used 400 grit. Then replace the O rings and use as is.

The magnetic plug: It's not unusual to find "magnetic mud", a build up of superfine metal from the gear meshes. Yours looks like a lot for only four times. When did you last change your lube and inspect the plug before this? Wipe the plug on a clean white rag or paper towel and inspect the residue large pieces. If the plug has been in for a long time the fine particles will build up on each other and look like yours.

Remove the top cover of your drive while it's drained and look at the gear teeth. Pitting on the contact surfaces is a bad sign.
 
Scott06

Scott06

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Run the engine with outdrive off and see if noise is still there to rule out ant accessories on the engine front making that noise. You can stuff a hose in the water port of left hand side of bellhousing with drive off.

Checks What is outlined above , metal on drain plug is normal for an alpha. What did the oil look like? Was there water in the bellows?
 
J

JohnsonBargeMan

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Mar 31, 2013
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Thanks for the input guys! Here are answers/input to your questions/observations:

Noise when turning: I don’t recall if it was louder or not.

Sanding the yoke: thanks, I’ll give it a try. Also, since it is taken apart, I’m going to put a new bearing in. Maybe I somehow messed it up when I installed it. (I didn’t use the correct tool last time, buying it this time though!)

Magnetic Plug mud: when I wiped it down it was powder, I couldn’t feel any grit. Only a little bit of shiny stuff, mostly mud. I wasn’t the last person to change the gear oil so I don’t know if it was even cleaned off last time. And to be honest, I don’t even know if the they did the gear oil change!

Remove the drive cover: I’ll try, don’t think I have that tool/socket

Run the engine: Just brought the boat home today. I’ll see if I can get some time between Easter dinner and company!
 
J

JohnsonBargeMan

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Here is a picture of the “mud” ( I couldn’t figure out how to edit and add the picture to my prior post)
 

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Q

QBhoy

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8,319
Gimbal bearing is a groaning, rotational droning noise. Not to be confused with a noisy UJ coupling. That’s a horrible knocking noise when drive turned hard left or right and tilted up a little. Caused by running engine with drive lifted too high.
 
harringtondav

harringtondav

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achris said:
You do know it's been updated a few times since 1996... ;)
Click to expand...

17 -23 ft/b averages 20. I may purchase a new #14 if/when I purchase my next boat. After I purchase the service/parts manuals for the 4.5L. Lotsa angst on that one.
 
L

Luv2fish36

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Joined
Apr 22, 2019
Messages
33
Be more descriptive on what type of noise it's making. Is it a knocking noise? Is it a high pitch howling/whining noise? Is it a low pitch rough grinding noise?
 
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