Vibration at low speed

[Skinnertes]

Just bought a 2005 Sea Ray Select w/5.0l MPI & Alpha I outdrive. During the test drive, I noticed that the boat vibrated during acceleration. The vibration was not excessive, but it was noticeable and you could feel it. The vibration goes away at higher rpm's. I plan on having the outdrive removed and inspected, but curious if anyone has experienced this vibration with their boat and what was the problem (if any). No noticable prop. damage - actually looks very good. Thanks

 

[billnpat]

Just bought a 2005 Sea Ray Select w/5.0l MPI & Alpha I outdrive. During the test drive, I noticed that the boat vibrated during acceleration. The vibration was not excessive, but it was noticeable and you could feel it. The vibration goes away at higher rpm's. I plan on having the outdrive removed and inspected, but curious if anyone has experienced this vibration with their boat and what was the problem (if any). No noticable prop. damage - actually looks very good. Thanks

Somebody will chime in to help you;
Welcome to the forum....:thumbsup:

 

[Jimmy Buoy]

Welcome!

You say it goes away at higher rpm's? If it shakes during acceleration and not while maintaining speeds it could be the engine stumbling. Once you feel the vibration has "gone away" at a particular speed, did it return if you were to accelerate past that speed?

 

[Skinnertes]

Jim, thanks for the reply. Engine operates smooth in all ranges. The vibration I feel occurs after I put it into gear and then accelerate. Since I just bought the boat on Friday, I'm going to have the outdrive removed and inspected just as a precaution. Not sure if it has ever been inspected before. I will have them check the alignment between the engine and outdrive to make sure it is ok and also check the prop for any misalignment or other issues.

 

[matthewmiller01]

Jim, thanks for the reply. Engine operates smooth in all ranges. The vibration I feel occurs after I put it into gear and then accelerate. Since I just bought the boat on Friday, I'm going to have the outdrive removed and inspected just as a precaution. Not sure if it has ever been inspected before. I will have them check the alignment between the engine and outdrive to make sure it is ok and also check the prop for any misalignment or other issues.

Just a thought... Have them check all of the gears (esp. the gimbal [I believe] that is the one transferring rotational energy from the engine [fixed] to the drive, specifically throughout the trim angles). Does the amount of vibration change at a constant speed for different trim settings?
(I hope you can figure out what I am saying by what I typed.)

 

[Skinnertes]

Just a thought... Have them check all of the gears (esp. the gimbal [I believe] that is the one transferring rotational energy from the engine [fixed] to the drive, specifically throughout the trim angles). Does the amount of vibration change at a constant speed for different trim settings?
(I hope you can figure out what I am saying by what I typed.)

Vibrations stays fairly constant thoughout the lower rpm/speeds. Once it gets around 25 mph, the vibration goes away. I am going to try and take it in this weekend and have it checked out. Thanks!

 

[OldSkool]

I believe Matthewmiller01 is on to it. The gimble is much like your drive shaft in your car. As the lower rpm requires more torque to get on plain the gimbal coupler may bind. As the speed increases the torque need falls off the coupler is less stressed. It maybe as simple as changing the coupler. One things for sure, if it is the coupler, it will take out your bearing in the drive if you don't get it fixed.
Just my opinion. Hope it work out for you.

 

[Scottbenson]

If would try the easy thing first. Try another prop and see if the problem goes away. I had a prop that appeared to have no damage but it was badly out of balance and the blades were not even front to rear when the prop was rotating. My boat had a vibration at low RPM that went away at higher speed. I had the prob balenced and straightened and the problem went away. If you could borrow another prop to try, this could be your problem or at least eliminate one area before you spend any money.

 

[Dave S]

Removing the outdrive is the correct thing to do for starters. If for no other reason that work needs to be done to verify everything is OK.

Once it is pulled then the Technician can check the condition of the bellows, the engine alignment, and the condition of the gimble bearing and the u-joints. If they are OK and If the vibration persists after that, I would suggest getting a new prop or having your current one trued and balanced (even though it looks OK). If you buy a new prop, then you can use the old one as a spare.

Dave

 

[OldSkool]

Dave S, Can they just pull the prop off the shaft and engage the drive? It shouldn't vibrate without the prop installed? You could do it with it on the trailer while backed in the water.
Thanks.

 

[Redhook98]

I had the same issues with a 2001 Monterey 190. It turned out to be a bent prop. The prop would cause a lot of vibration as soon as I put it in gear, but "seemed" to go away when the revs got higher. save some time and $$$ and check your prop first. Just throw any good prop that will fit on there for a quick 2-minute test run. It won't hurt the boat and it's a down-and-dirty quick check (performance may suck, butyou are checking for vibes). That will save having to pull the outdrive, maybe.

 

[Dave S]

I had the same issues with a 2001 Monterey 190. It turned out to be a bent prop. The prop would cause a lot of vibration as soon as I put it in gear, but "seemed" to go away when the revs got higher. save some time and $$$ and check your prop first. Just throw any good prop that will fit on there for a quick 2-minute test run. It won't hurt the boat and it's a down-and-dirty quick check (performance may suck, butyou are checking for vibes). That will save having to pull the outdrive, maybe.

I agree you can take this route first but I still think the drive ought to be checked as well......see my comments below.

Dave S, Can they just pull the prop off the shaft and engage the drive? It shouldn't vibrate without the prop installed? You could do it with it on the trailer while backed in the water.
Thanks.

I am not sure that running the drive without a prop will determine anything but I suppose it won't hurt to try it. I just think the dynamics of a prop spinning in water under load are a lot different than running a drive in the yard with no prop.

Also, don't forget this is a five year old boat that he just bought if I read his posting properly. If I were in the same situation and had just purchased the boat, I would proceed along the same lines that I recommended. I would first have the drive pulled to make sure everything is OK. In my opinion drives should be pulled once a year anyway. (I have always done that with my boats and I feel the expense is is well worth it.) And several years back, the u-joints had to be greased (now they are sealed) and the only way that could be done was by pulling the drive (I do not know if his 2005 model Alpha drive has the sealed u-joints or not). The drive splines should be greased as well. But first and foremost you want to know if the bellows are in good condition because a leaky bellows can damage the gimball bearing if water gets into it. I always changed my drive fluid yearly as well. So even if the drive itself does not turn out to be the problem, I recommend he have the drive pulled and serviced (unless of course he knows it was done before he bought the boat).

Dave

 

[OldSkool]

Dave, I understand what your are saying about the dymanics of the prop torque in the water. Much like back pressure caused by exhaust in the water rather than on the muffs.
Thanks.

 

[Skinnertes]

Thanks for all the replys and feedback. I like the idea of testing out a known good prop to see if the vibration goes away. I will try this out. Like many of you have said, I still need to have the outdrive removed and a thorough inspection made. That will be done next week. Thanks again