lower unit rebuilt
 

i bought a merc manual when i purchased my boat , its detailed in repairing everything on the engine . i decided to redo bearings and seals in the unit and took on the task my self . the gears looked good and clutch dog was ok . so i redid seals and bearings only .. put it back together and new merc performance synthetic gear oil in ...took the boat out sunday and put maybe an hr run time on engine and gear case , pulled the boat and check the gear box lube. took some out and it looked like glitter in the gear oil.... so i was kinda like damn did i screw something up? i ended up pulling it all out into a very clean container . i swished a magnet around in the oil and no chunks , and barely any on the magnet. i then got painters filters with 226 micron screens and ran the oil through that and still no chunks ...so the metal particles are very very tiny.. everything i read or see is that its ok as long as no bigger shavings or chunks ..... i even lut my ear up to the gear case and spun prop and shaft to see if i heard any funny noises inside but it all sounded smooth inside ....what are some of your thoughts about this ??? do u think its ok to have glitter after only an hr of runtime

Re: lower unit rebuilt
 

Wondering if it could be the switch to synthetic that freed up all those particles. If they had been metal then I would assume the magent would have trapped them.

I guess I would start off with another fresh fluid change run it, inspect again and go from there.

Re: lower unit rebuilt
 

gerry , i always used the same gear oil, been synthetic since i purchased the boat. there were some shavings on the magnet nut that hold the fluid in . and the glitter is metal but very small particles of metal that just isnt big enough to stick to the magnet i swirled through the fluid ...im thinking being i pulled the guts out and put back in the fine adjustment have been knocked out and now its just adjusted slightly off from before ..which is prob creating extra shavings ...like i stated previously i pulled the gears out in order to do the bearings ...

Re: lower unit rebuilt
 

I'm coming from the automotive end of this...have very little experience in the marine version..

....that being said, what you are probably seeing, are coatings coming off the new bearings on the initial run in.

Glitter is ok, chunks are not. Your fine IMO

Re: lower unit rebuilt
 

I'll throw this out there, but thankfully I haven't gottten into this field of BOAT yet....just knocked on wood, if it's metal, the magnet should grab it,some way. Now this is only a throw it out there thought-but for example: not all engine or transmission or gears... And so on are metal, they may be brass, chromium,copper... Yada yada. It could be brass from an insert bushing, but not likely. It's not bad to be too cautious though.
- my examples of some metals were just examples of what ya get for oil analysis on diesel engines so don't quote anything I mention, just saying maybe the glitter is not metal, initial ? Was why isn't the magnet picking it up????
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Re: lower unit rebuilt
 

Did you take a pic of the glitter? I use quicksilver and it may just be the oil too...

Re: lower unit rebuilt
 

no pics , i did filter the oil through car paint filters and only a little bit of metal got caught on the filter screens , inuse the mercury high performance gear oil ...blue in color ! the glitter is definitly metal but very tiny particles ...im thinking im good , just didnt think itnwould happen so fast with an hr of run time figured over time ...i usually change the oil every season ...never changed that fast !

Re: lower unit rebuilt
 

X2

If you ran for an hour without overheat alarms and only had "glitter"...all's well. Bearings running in their chase for the first time at high RPM, gears finding themselves again. There's a lot going on in there. I'd run it for a month and change the oil again just for peace of mind.

Nice work!