I am getting a loud clunking kind of noise when shifting from neutral to forward or reverse. Engine is idling at 700-750. In gear 600. Its louder when the boats on the trailer running . I drained the drive oil today and noticed a small amount of black sludge on the magnets and a slight darker change in oil color. I am running Amsoil Marine gear lube. This lube is normally clear. My other drive was fine. Very clean oil. Is this normal wear. Original Bravo 1's. This drive turns clockwise port side of boat

Any suggestions
Thanks

Is it a kind of cluck cluck cluck sound? Sound is consistent?

I spoke to a Mercruiser mechanic and he said that clunk while shifting is probably because the idle is too high and i'm hearing the gears ingageing. He said all Mercruiser engines idle @600 rpm's. I can;t idle mine down that low because of my cam profile. He also said that the drive is crisp. Drives that go into gear with no noise (bravo's) usually have more wear on the cone clutch + gears and will probably fail soon.

mine is more noisy when shifting out of the water...clunk...seems normal to me..

Does it clunk when you go fwd neu fwd? Or does it require reverse neu fwd to hear the noise?