Mercruiser 4.3 Clunking/Knocking Noise (video)

[brsox88]

I have this 4.3l Mercruiser from a 2002 Starcraft that is making a noise I am not sure is normal or not. It sounds like a train chugging along on the tracks. You can easily hear it in the video below. It sounds slightly like metal on metal. Could this be caused by the gear/drive lube oil being completely empty?

 

[Bondo]

Could this be caused by the gear/drive lube oil being completely empty?

Ayuh,.... Yes, of course it can,... Is the drive empty of oil,..?? why would you start the motor then,..??

Is the drive trimmed to Full Up,..??
That's also a No-No,...

 

[harleyman1975]

How is oil pressure? I hear the noise but it is not a Knock that I would associate with a bearing. those are usually a clack clack clack sound.

 

[brsox88]

If it weren't raining I'd run outside and pull the bottom screw to see. I just figured it wasn't an issue because it was lube for only the outboard unit and was only important if I had it in gear? The noise seems to be coming from the engine itself, which should mean the gear lube oil would have no effect on this?

 

[Bondo]

Ayuh,..... In the Alpha drive,... Everything but the prop shaft, turns with the crankshaft,....

The shiftin' is done on the prop shaft,....

Even with the Bravos, 'n Volvos, the upper gear set turns with the crankshaft,...

Was it trimmed to Full Up,..??

That tears out the u-joints,...

 

[brsox88]

Uggh well I suppose that may be the issue then. And yes, it was running in the full up position :facepalm: but no more than 3-4 minutes total that I have owned this boat.

Thanks for the help, I really appreciate it