vibration

[scoflaw]

What level of vibration is acceptable? Mine does it hard left,right and trimmed up. The bearing feels smooth. Same with U joints. Nothing obvious. Coupler looks good too. Should I just change things out anyways?

 

[ziggy]

Re: vibration

understand that i ain't the pro. but here's my wag.

The bearing feels smooth

as in absolutely smooth. no feel, no sound?

Same with U joints. Nothing obvious.

i've read more than once that ujoints can appear ok while in fact they are not. imho, this would be the first place i looked for the described vibration. even it they seem to be good. assuming that.

Coupler looks good too.

did you run the alignment bar and find that in fact that it was in alignment? checking alignment at 0*, 90*, 180*, 270*. assuming alignment is good. i'd go back to the ujoints.... imho..

 

[Bt Doctur]

Re: vibration

"What level of vibration is acceptable?"

None

 

[ziggy]

Re: vibration

another thought occurred to me, hows yer props? dinged and bent out of shape. any pieces missing out of the blades. the prop needs to be pretty pristine or they can cause vibration...

 

[Bt Doctur]

Re: vibration

not many places for vibration
flywheel
coupler issue
U joints
gimbal bearing
prop shaft
prop

 

[brhodes]

Re: vibration

I'll chime in regarding the gimble, I'm a noob, mine felt good/smooth/no noise when I checked, but it made the ole growl when i turned. When I put a new one in, problem solved. It sounds like you have a u-joint issue though, or possibly something else. Just my .02, good luck

 

[telstar1]

Re: vibration

Im thinking coupler.Assuming u joints are good(ive never had them fail, personally),also brg and alignment. Ive had the same quandary as yours twice over the years and each time it was the coupler. Last time i really could not see what I considered to be a significant difference between old and new just a bit more side to side slack in splines is all, "trueness" about the same.,yet the new coupler solved it.I can only assume the slack thing was significant.
BTW
1.I had to get two couplers before I got a new one that was as true as the old "defective" one.A new coupler is not necessarily a good one.
2. The slack in splines Im talking about was not in my case anyway a rotational thing ,but rather a side to side slop.You can test for this with a 1 inch bar, insert it all the way, see how much it moves side to side. Helps to have a new one to compare it to. Im assuming there is a textbook way to check this and someone will chime in with it, that is how I did it.
3.Id imagine that significant slop in gimbal pins could give vibration like you describe. Have never beebn there myself.

 

[scoflaw]

Re: vibration

My pins are nice and tight as well. My coupler alighnment was less than perfect, but the splines and rubber looked fine. A marine mechanic said it was good enough and they don't all line up pefectly. Wasn't 2 fingers in and out. Gonna go with a new bearing and joints just for *****s and giggles.????

 

[ziggy]

Re: vibration

not many places for vibration
flywheel
coupler issue
U joints
gimbal bearing
prop shaft
prop

My coupler alighnment was less than perfect, but the splines and rubber looked fine.

my guess is they won't for long. from what i understand, miss alignment is what leads to coupler failure

A marine mechanic said it was good enough and they don't all line up pefectly. Wasn't 2 fingers in and out

i'd find a new marine mechanic.

you've got a vibration, and you have failed one of the test that can lead to vibration. that, to me, seems like a starting point as to a repair.. imho.

 

[scoflaw]

Re: vibration

This is the original 10 year old coupler, and as I have said rubber and splines look just dandy. Seeing this part costs big bucks, I think the most cost effective way to go would be bearing and joints. The marine mechanic I spoke about is the head honcho at Hyannis Marine, a big Sea Ray dealer in Massachusetts, who said that it's not uncommon for the transom to be off a bit.

 

[fishrdan]

Re: vibration

My coupler alighnment was less than perfect, ,,,Wasn't 2 fingers in and out.

It should be perfect, 2 fingers in-out... Unless you like pulling the engine to replace the coupler. When was the last time the engine aligned?

 

[ziggy]

Re: vibration

This is the original 10 year old coupler, and as I have said rubber and splines look just dandy. Seeing this part costs big bucks,

i'm not suggesting to buy a new coupler. i'm suggesting that you align it. if the alignment is off. it seems that this could be your vibration. + if you don't align it, the splines or the rubber will wear out from being out of alignment. coupler failure.
as for cost, it don't cost anything to align it if ya got the alignment bar. just time to do it until it is correct. if it can't be corrected then something is causing you to not be able to align it and further investigation would be necessary.

glad ya have a mech. that you trust. i suppose trust them more than me as i'm just joe boater. but this is what i understand to be. i could be wrong. like i said too. ujoints can look and feel good too and not be. so maybe that's the way to go. but i still think alignment needs to be corrected.

fwiw. my coupler on my '75 is original best i know.
i've fought with alignment for sure. i've had it wrong (bar to tight) and i've had it correct. bar slides in and out with a couple of fingers. when it's right you know it, when it's wrong you can talk yerself into that it's ok, but in the end you know it's not and that your treading on thin ice that may lead to coupler failure.

that's my 3 cent worth...
good luck with her and let us know what ya end up doing and how it works out for ya..

edit..

poor alignment.. http://www.youtube.com/watch?v=fA5ExlPVz2w&feature=related

proper alignment.. http://www.youtube.com/watch?v=MYwnK8mjHdw

them videos helped me decide what was right and what was wrong..

 

[scoflaw]

Re: vibration

I had the engine out recently. Before I pulled it, I checked the alignment. Not that great. Figured I could make it nice when I put it back in. Up, down and spent a lot of time with it. No matter which direction I go, it only gets so good. It might be a little better than when I pulled the motor. Seems like the rear of the motor might want to be a tad higher. If its been off for 10 years, I would think it would have failed by now. I have owned this boat for 2 seasons and its getting worse.

 

[cr2k]

Re: vibration

Not sure how the transom being off can effect this as the motor mounts to the transom. If you don not get the spring and washer stack (rear mounts) right there will be problems.