Drained the oil in my Bravo 1 today. I use the Merc High Performance gear lube. The oil was black. I usually change it every 25 - 50 hours. This year I didn't,(lazy) it had 100 hours on it. In the past, the lube goes in green and comes out green. I took the top cap off and did a quick look. Didn't see anything. The bottom plug with the magnet didn't have anything on it. No silver specs in the oil that I could see. I'm thinking must be some clutch slippage along with too many hours between oil changes. I guess I'll pull it apart to inspect .
Pushing around 600 hp.

Any thoughts???

Noise,
I am not sure what the chemical reason is for it turning black, but I suspect the lube has broken down. And you are correct it is due to long interval between changes. I suspect heat is an issue. Is your drive shower really cooling the lube down? Best place to look for damage is in the tappered bearings. The clutch only slips when put in gear and that is only for a moment, unless it doesnt go into gear right away. I had a slipping clutch for a month or better and the lube didnt turn black.
On a second note, I cant remember if got back to you with a quote?? Send me a pm and remind me what we talked about. Sorry, I just have been overwhelmed with my day job..

Hope this Helps..
D*ck

Quote:

Originally Posted by Mr Gadgets

. I suspect heat is an issue. Is your drive shower really cooling the lube down?
D*ck

I agree with that .....check for your drive shower .....mine was packed with some wood sharp ....and cost me a upper $$

There's no signs of over heating the drive. No white residue on the outside of the upper. But then again thats no real test.

Probably just too many hours but keep a close eye on this. Had a friend that ran into the same problem. Drained last fall and the lube was black but no metal. Drained this fall and the lube was black and both magnets had tons of shavings and the lube glittered in the sunlight from all the shavings suspended in it. Drive is currently being tore down to determine the cause.

I'll make sure I change it every 25 hours this summer.

excess heat and friction will burn the gear oil !

Seen a couple of drives that did that.Jet black oil. It was very slight mis-adjusted shift cable.Customers noticed no slipping or performance loss,but indead the cones had slipped.Started to push out input seals too.