Spun Prop Hub

[boatsnbeats]

I was on the lake the other day and I heard a clunk and then some knocking in my port outdrive. I have a Merc 5.7 with an Alpha 1. I just replaced the shift cable this spring. It still seems to be shifting but feels sluggish at the helm control. If I shift into gear and spin the prop it does lock into position. Could this be a spun hub from hitting a log? It will not shift into gear or at least move at all under power even though with the engine off it seems to be going in and out of gear. Will the prop still feel like it locks in gear if it is spun or does it just spin freely when it is spun? I am trying to eliminate all possiblilities before I have the boat pulled out of the water. I'm not sure but I should be able to pull the prop while it is in the water.

 

[Brewman61]

Re: Spun Prop Hub

If you can, make a mark on the prop and an adjacent mark on the hub. Then go for a spin(so to speak). If the marks move, the hub is spun. If they stay in alignment, chances are the hub isn't spun.

 

[boatsnbeats]

Re: Spun Prop Hub

Thanks for the quick reply. Unfortunately my boat is in the water and the prop is under water so I can't mark it. Would it be easy to remove it under water or would that not show me anything?

 

[tractoman]

Re: Spun Prop Hub

You could raise the drive and mark it with a grease pencil and then check it out.

 

[Bt Doctur]

Re: Spun Prop Hub

Could raise it almost all the way out and give it a quick test in fwd to see what spins.prop, prop shaft, or nothing moves.
Can also lower the drive , start the engine and put it in gear at 1000 rpm. If it overheats, a broken shaft or coupler. If it dosent overheat it may be a broken pinion gear

 

[180shabah]

Re: Spun Prop Hub

Prop hub may be spun, BUT...

I heard a clunk and then some knocking in my port outdrive.

This sounds a little more serious than some "broken" rubber.....