View Full Version : Drivetrain

08-02-2017, 11:42 AM
OK, so cruising down the lake at about 4,000 rpm when I hear a bang and then as I throttled down hearing a sound like beating a pan with a metal rod. Once I determined that I could proceed at idle speed I made it back to berth. Halfway home the noise subsided and then quit. Never tried to load or reverse. Boat guy will get to it later. But just curious if anyone else had such an issue? Stock Bravo unit with 500+ HP.

Morgan's Cloud
08-02-2017, 01:22 PM
D*mn you gotta just love boat problems .
How on earth could a noise like you describe completely go away after a few minutes and everything seems fine ?

I'd be angrier that it stopped than kept doing it .

Wish I had some more constructive input for you though .

John C in PA
08-02-2017, 02:14 PM
B.O.A.T. I'm sure you know the long version!!!!

John C

08-02-2017, 08:37 PM
Did the sound come the drive or the engine?


08-03-2017, 12:03 AM
From the drive, either bell housing or the upper. Engine running fine, just under a load from something maybe sporadically binding.

Morgan's Cloud
08-03-2017, 06:56 AM
OK , I thought a bit and might have something a little more constructive to offer 2nd time around .
It might not be your problem but it never hurts to throw these experiences out there.

We had an unknown alignment issue a few years ago that when it manifested itself it made noises from the back of the boat that sounded like someone dragging anchor chain up onto the deck of a tin boat . It would do it completely randomly , start unexpectedly , last a few seconds and then stop . Never knew what it was until after an hour or two the splines on the coupler disappeared !

08-15-2017, 09:59 AM
I had a noise on my Z25 KC drive that sounded exactly as you describe this one and it turned out to be the upper gear set exploded........:frown: and this happened with a very mild 460 at the time, maybe 400 horse on a good day. route cause in my situation was in sufficient oil, the bearing failed and over the engine i could not hear the noise until it was too late and the gear set failed. if you havnt already take a look inside your outdrive and see if you can see anything, never know you may get lucky with a minimal repair.

Kenny n.
08-16-2017, 01:08 PM
If the out drive was not the cause of the noise it could have been caused by the windage tray . Maybe it cracked near one of the mounting bolts and the crankshaft was hitting it. The only other thing could have been a bolt,nut or a washer flying around inside the adapter housing .
Hope you can find out what it was.

08-21-2017, 07:12 PM
Sound was behind the engine, either bell housing or upper drive.