Prop is making thumping / clicking noises when hand rotated (video)

[ryno1234]

When rotating my prop by hand, I hear a thump / click noise (Alpha 1 Gen II). This happens in both directions but is considerable quieter in one versus the other. I tried using various shift engagement on the shift control to see how that might affect the noise thinking maybe I'm somehow slightly in gear, but I couldn't seem to find the sweet spot where the noise would go away, it was always there.

I did just replace my hub because my last one had the castlenut teeth slightly bent out. We took a hard wave at heavy throttle and I think the prop nut twisted. I'm just speculating, but we couldn't get on plane after that very easily and there was a definite vibration. Replaced the hub and vibration is gone and I can get on plane, but now I have this clicking / thumping

You can see a video of it here:

Any ideas?

 

[TMW123]

That definitely sounds like the dog clutch is dragging a little to me. If you start it in neutral does the noise continue? I think a cable adjustment might be needed.

 

[Texasmark]

From the rear trying to turn the prop CCW results in resistance and the prop doesn't want to turn.....that is for F gear. Slowly turning the. prop CW and watching the prop in relation to the LU casting and listening, you will notice the prop moving away from the gear case slightly and then returning abruptly....like the teeth on a saw. As TMW stated, that is the overrun clutch functioning.

The purpose of the clutch is to disconnect the prop from the powerhead any time the prop is turning faster than the engine.....like when ypu are coming off plane. If you were on plane and chopped the throttle without the clutch function you'd have to dig your teeth out of your windshield.....if you had one.....figure of speech.

 

[ryno1234]

Yo

...the purpose of the clutch is to disconnect the prop from the powerhead any time the prop is turning faster than the engine.....

You mentioned Powerhead. Just being clear, this is an I/O Alpha I Gen II. Perhaps the comment is just as applicable, just wanted to be clear

I appreciate your help as always.

 

[StewartL]

That click is not normal and indicates an internal issue.

Since the noise started after your hub replacement and hard impact, the problem is likely inside the lower unit. The most probable cause is a damaged forward clutch dog or gear. The impact that bent the prop nut likely also jarred the gears.

You need to have a mechanic inspect the lower unit. Running it could cause further damage.