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cjm13905

Change Gear Lube - found metal filings

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In July of  2018 I got an entire lower unit gear  replacement.

This weekend, when I changed the gear lube, the lower nut had some tiny pieces of metal. Wish I took a pic, but didn't have my camera. I would say the pieces were about as long as the exposed eraser on a #2 pencil, and would occupy about 1/16 of the eraser. Is this something that should be expected, keep an eye on,  or be concerned about ? 

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FULL checkout of where they came from is in order.  NOT a good sign.

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Thinking positively- could they be shavings from the previous set of gears that remained in the case? Why did you need to replace the gears in 2018? What type of drive?

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It is an Alpha. The lower unit just failed. Although the prop was fine the Mechanic said that based on the damage it looked like we hit something. Unfortunately the insurance company did not agree, and did not pay anything.  

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I would monitor it and plan to take a sample of the fluid every once in a while to see if it gets worse. 

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Wingnut can correct me.  But can the chips be from the UPPER gear case ?

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10 hours ago, cjm13905 said:

In July of  2018 I got an entire lower unit gear  replacement.

This weekend, when I changed the gear lube, the lower nut had some tiny pieces of metal. Wish I took a pic, but didn't have my camera. I would say the pieces were about as long as the exposed eraser on a #2 pencil, and would occupy about 1/16 of the eraser. Is this something that should be expected, keep an eye on,  or be concerned about ? 

Not sure what motor and drive, but not normal for any brand. If it were mine, I’d first go back to whomever did the lower. If not an option, time to pull the drive, disassemble and correct this winter in a nice warm shop. Metal is not a good and it won’t get better (debris going through a gear box always causes more debris with further damage). If you’re curious, and still have the bits, almost any oil analysis service can determine what they likely came from due to different metallurgy and heat treatment (gear, bearing, pinion, etc.). Disassembly will answer this question as well. Sorry, best.

Edit. Sorry, I see now that it’s a Mercury Marine Alpha. 

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I'm with Cyclops. (first time for everything). You may have failed the lower, and if the upper was not taken apart, cleaned, and re-sealed this may be a continuation of the first repair. If it were me, I'd stop running the thing and pull apart both the lower case nose cone and upper case top cover and input shaft bearing carrier for inspection at the very least. Bearing rollers and races do not like particulate, nor do the contact point of the gear teeth. Your Alpha has a simple dog clutch, so no cone or socket to wear, but something is still amiss. Upon reassembly, be sure to fill your Alpha with Merc's HP lube as it does a better job than their cheaper "Premimum" lube.    W

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