Metallic Sheen in Gear Oil


secondtimearound

secondtimearound

New member
My mechanic was doing maintenance on my BIII X drives and noticed a slight metallic sheen in the gear oil of both drives. They are 2009 vintage. Has anyone experienced this? How could both drives have a similar issue? The drives were last off and serviced in the spring of 2019, about 200 hrs ago.

Thanks for any input.
 
Sounds like cast off from the cone clutch's, but without pulling apart to check its only a guess. The amount of metallic your seeing is what's important, if there is any thing other then a little dust it needs to come apart.
 
Thanks, AJK. It appears the drain plugs of one drive have collected some small shaving. The oil in both drives has a very strong burnt smell. I assume that is from high temperatures. I guess without the drive showers the gear oil would break down faster and failure would occur pretty quickly.
 
I'd run drive showers that'll take away the over temperature of the gear oil. 200 hours is a long time before changing gear oil. I wouldn't go any more than 50 hours. I agree with above poster the cone clutch is shedding off bronze which is normal.
once I put drive showers on my 28 SS the liquid burnt smell was gone and oil came out normal consistency.
 
Can you provide a timeline and what exact maintenance was done? Was it really 200 hours since the last oil change, or 200 hours since the last re-seal?

Oil change need to be every year, or every 50 hours if more than 50 hours in a year. If it's indeed 200hours, it's not surprising the oil smelled burned.
 
Agree that 200hrs is way too long, I have run mine close to 100hrs and I have drive coolers but don't really recommend it. It came out black and a little smelly but not burnt yet. Bravo III run hot especially in the upper drive, I have had mine apart and replaced my cone clutch's so very experienced with the drive. Heat and lack of maintenance is about the only thing that will hurt these things, change the oil every 50hrs and install a drive cooler and you have no worry's.
 
I don't want to detract from the original question, but I put 100 hrs on my Bravo1s this summer. Port oil came out looking brand new minty fresh greenish blue.

Starboard came out green, but dirtish like lightly used motor oil. No known issues in either.

they are over 700 hours, each. thoughts? I change drive lube every fall. OEM only. no water in either.

the dirt difference is even noticeable on the drive reservoirs in the engine bay. port was much more green vs light brown... I wish I took a pic, but was mid-installing my new steering.
 
Last edited:
Sabr
I wouldn't get too worried about that, if no metal is present when you change the lube then it should be fine. Now you have B1 not the B3 the thread is about, B3s run warmer because they are usually pushing a heavier boat and also by the drive's design. I remove and clean the inside of those lube monitor bottles every 2 years. Those things just seem to collect the gunk, also 100hrs is what merc recommends on the drive oil but I don't run mine that long. Lube is cheap compared to a drive and I still recommend installing a drive cooler, cheap insurance for your bravo.
Just my 2 cents
 
I'd like drive showers and it's on my list - last winter though was 2 new engines, and this winter was new IMCO external steering and helm - budget only goes so far each season.

thanks. Yea, I actually just replaced the reservoirs a year or two ago as they were nasty and I assume never changed over 20 years.

My boat's on a lift all summer, so changing the drive lube would not be very simple for me, so it's usually every fall. I just happened to hit 98 hours of engine run time this summer!
 
There's definitely a reason why it's coming out darker it's working harder for some odd reason could be preload on bearings could be deflection in the output prop shaft causing gears to wear more. More friction more heat.
 
Sorry it has taken so long to reply. I do have drive showers and due to covid my regular spring outdrive maintenance was pushed to the fall. Also, I did not realize 50 hrs is recommended service interval for BIII's. Anyway, after further investigation the lower gears were badly damaged, 3 teeth sheared off. I had hit something earlier in the season and did not realize how severe the damage was. This was a costly mistake. New drive on the way and I will be ready for the spring. Thanks for all the good information.
Merry Christmas to everyone.
 
If the cases are undamaged, get them back from the mechanic. They are worth $$$$$ for people with good internals and corroded cases. DO not assume the part have no value.
 
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