Alpha One upper outdrive noise

[mguidry629]

We were just cruising along yesterday, celebrating the birthday of our great nation when the drivetrain started making noise and vibrating the boat. My first thought was lower unit, but it was making noise in forward, neutral and reverse and it sounded like it was coming from the back of the engine so my next thought was gimbal bearing or coupler. This morning I pull the drive and the gimbal looks and feels fine. So I rotate the drive shaft on the outdrive and it's got a "hard" spot in it. I can turn it fairly easily until it gets to this one spot. Makes no difference whether it's in forward neutral or reverse.

The boat was still functioning as normal in forward and reverse but this noise had me concerned, especially with the vibrating of the boat, so I shut it down and got towed in (thankfully only one mile from the landing).

Any ideas on what could be wrong?

I wish I had a video of the noise for you but I already pulled the drive off. Not really a grinding noise, more like clunking.

And here's the kicker: The boat is for sale and I have a buyer lined up, but I wanted to take it out one last time before I sold it. What are the odds?

 

[oldjeep]

Re: Alpha One upper outdrive noise

NO matter what, you are going to have to take the outdrive apart. Separate the upper and lower and then redo your test. That'll tell you weather the bad bearing or gear is in the upper or lower.

 

[ziggy]

Re: Alpha One upper outdrive noise

as your draining the gear lub. inspect for metal fragments too. specially the initial lub that comes out. assming it's been sitting for a bit. if there's metal fragments in the gear lub they'll sink to the bottom if they can. or metal dust too.

when the upper and lower are together. everything is turning inside the drive when in fwd or rev. when in neu everthing is still turning except the prop shaft.

pretty easy to remove the top cap on the upper. ya can see some gears (though not all of them) with the cap off. if ya do that, use a new o ring on the cap. cheap and very critical part keeping lub in and water out.

hows the prop? hit something and take a chunk off a prop blade and it'll vibrate.

hows the ujoints. they go bad and it'll vibrate.

since your feeling a hard spot while rotating the drive shaft. it does seem likely to me that something may be amiss inside the drive. and agree with oldjeep too. separate upper and lower to discover which half is the offender.

 

[mguidry629]

Re: Alpha One upper outdrive noise

It's definitely something inside the drive. The prop looks great...didn't hit anything....Drained the oil and it's milkshake with metal shavings. I'm trying to separate the two halves now and something is holding them together. I've separated them 3 times before, so I know I'm not overlooking a bolt or nut, but that's what it seems like. It should just fall off, but it's not budging. Oh, and also the drive is completely stuck now...I can't turn it forward or backwards, but I'm not able to get much torque on it.

Any ideas of what could be holding the two halves together?

 

[mguidry629]

Re: Alpha One upper outdrive noise

Okay, I forgot about that one bolt, lol....and my two halves are apart. The problem lies in the lower unit. Upper still turns freely, lower is seized up, can't turn it either way....I found a lower unit in good used condition that a buddy of mine had. So I assume if I am to mate my upper with the "new" lower, I need to clean out the gear casing in my upper to make sure there's no metal shavings? How would I go about doing that?