Gear shaft not rotating while engine is running

[SimeC]

Today, everything start normal. Clutch fwd/aft was working fine. Suddenly I lost propulsion. Clutch fwd/aft dead.
Engine running normally. Checked propeller, on the place.
Checked shaft that is going from gearbox to the engine, not rotating, engine is running.
Assume shaft teath are worn out.
Please find attached video

 

[Bt Doctur]

Engine coupler went from lack of service or collapsed rear mounts affecting engine alignment

 

[SimeC]

Thanks Bt Douctur.
Rear mounts are ok.Engine is aligned well. No vibration whatsoever. Engine has been out of the boat for major overhaul last year.
Forgot to tell. Tried with open wrench to turn the shaft, easily turning in neutral.
I assume that shaft going to engine coupler broke.
Couse increase the rpm to 2000 and the shaft slowly turn half of turn without any grinding noise

 

[thumpar]

Looks like shavings. The teeth in the coupler are probably gone. They are softer than the teeth on the shaft. Can happen from lack of grease on the shaft. The motor will have to be pulled to change the coupler.

 

[SimeC]

Thanks Thumpar
Will take the boat out, remove the bravo 1 leg and will check.
Thank you guys. Appreciate a lot.

 

[Bt Doctur]

couplers go from lack of grease, lack of maintance or collapsed rear mounts. Was the drive ever very difficult to remove, was the drive very difficult to install. These are sighs of bad rear mounts

 

[Rick Stephens]

Replace the coupler, it's shot. Inspect the shaft teeth for wear as well. I can't see how you would think a shaft was broken when your picture appears to be coupler spinning but shaft isn't.

 

[SimeC]

Yes. Last year the engine wasn't properly aligned.I checked on YouTube and found that my engine was noo aligned at all. Central bearing hhasbeen changed on service shop account. Unfortunately, Mercruiser engine in my town where I live is a big mistery. Believe it or not.
Last year you guys teach me how to adjust Weber carb, and I was showing offical mechanic how to adjust the carb.
Do I have to tell you anything else
Anyway have one more picture. Definitely .lack of grease.
My mistake.

 

[SimeC]

Rick Stephenson,
That is the reason why you are commander and I am little idiot cadet asking questions

​​​​​Thank you sir

 

[SimeC]

Rick
joke aside. I assume that shaft is broken, couse engine is running, I am "diving" around bell housing and can't hear any grinding sound.
And as I told above. Increase rpm to 2000 and the shaft start to turn very slowly without any grinding noise.
Appreciate your reply

 

[SimeC]

To clarify, assume shaft is broken. The broken pice is inside the coupler

 

[Bt Doctur]

And from the looks of it there has been water in that area too , hence the rust.