Transom area vibrations/noise

[mark1905]

97 Alpha 1 Gen 2 I4:

When the boat is anything but on a perfect plane running straight ahead, I'm getting a vibration/noise from the rear transom area. It feels like anytime there is water pressure on the outdrive such as when I'm turning or the boat is trimmed all the way to the extreme up, I'm getting the noise. It's progressively getting louder, too.

The gimbal bearing was replaced 2 years ago, and the u-joints done last year. Fluid was changed last year and there is plenty in the reservoir. The play in the out drive seems normal as per my mechanic last time he looked at it. Prop spins perfect.

Any suggestions?

 

[Don S]

Re: Transom area vibrations/noise

Pull the outdrive and check for water in the bellows?

 

[mark1905]

Re: Transom area vibrations/noise

Will do. Looks like for any type of answer, we're going to have to pull the outdrive. The bellows though were all replaced at the same time as the gimbal bearing, and after checking just now they all look to still be in great condition.

 

[cr2k]

Re: Transom area vibrations/noise

From what you describe my first thought is U-joints. However you should never run your engine with the drive out of the trim range. Running with the drive full up may have caused your U-joints to fail.

 

[mark1905]

Re: Transom area vibrations/noise

Lol.. by "all the way up" I meant being at the top of the trim range.. not literally all the way up. I'd like to see the boat that can run with the out drive in the trailering position.. that would be interesting..

 

[Don S]

Re: Transom area vibrations/noise

Lol.. by "all the way up" I meant being at the top of the trim range.. not literally all the way up. I'd like to see the boat that can run with the out drive in the trailering position.. that would be interesting..

Trust me, it happens all the time, sometimes people are lucky and it doesn't destroy the transom shield.

 

[mark1905]

Re: Transom area vibrations/noise

Just a quick follow up for reference purposes:

It was indeed a completely blown apart, rusted gimbal bearing. It looks like when my mechanic did my bellows, the metal press ring didn't seat properly and was leaking water into the u-joint bellow. The bearing was so shot that he saved it to show other customers.. I mean seriously. I can't believe the noises weren't worse after that.

Moral of the story: growling, vibration noises coming from transom in an inboard boat are most likely that bearing. Pull your out drive ASAP and check it out.