[tobqluu]

I just took my boat out last week, on the way back from the water the lower stern drive was making a clucking noise and the engine just have enough power to get me back to the dock. I thought it was a spun prop, but i just bought a new one and put it on today and started the engine the noise is still there, at low rpm the noise its loud, but at higher rpm the noise seem to go away. The Prop spent freely with the engine off without any nioise. The noise seem to be coming from the lower stern drive.
(1995 Tarlari Z20 MercruiserAlpa one 4.3L ) i just bough it last year .

[IowaWing]

Check the stern drive condition by checking the lube in the drive. Drain a little out from the lower drain plug on the stern drive and look at the color:
Green is Good - Indicates all is OK
Black is OK - Indicates the lube needs changing
Grey is Bad. - Indicates water in the lube - seals and likely bearings are needing replacements
Metalic Grey is Really Bad - Indicates seals, bearings, and most likely gears are needing replacement.

[tobqluu]

Thank you! if its bad, would it be cheaper and easlier, if i just get a new lower drive or should i try to replace the seals, bearing and gear ? I've work on cars engine b4, but never touch a marine engine til now. How hard is it to replace them?

[mikeyt]

Have a look at the "How Do I..." site for you from Mercstuff.com which provides excellent photos & instructions on common maintenance & repair issues.

[IowaWing]

I have never attempted this project as it requires special tools and deals with close tolerances. If you have metal in the lube then I would suggest either a good used unit or have your outdrive professionally rebuilt.

[tobqluu]

I will a professional to take a look...thanks!

[tobqluu]

I just check the oil in the Stern drive...no water or metal, the oil is kinda dark green.

[IowaWing]

OK. Good to hear that. Per my first post "Green is Good". That color indicated the outdrive is OK. My guess now is that you have an engine problem. Was the temp within the operating range and was the oil pressure good? It is probably time to take it to a professional for a diagnosis and estimate of repair.

[tobqluu]

ran the engine...at
idle = no noise
1/4 throttle = noise
1/2 to full throttle = noise goes away ( maybe engine is too loud to hear it)
Reverse = no noise