185 sport mystery noise

[dieselsmoke]

So on my 07 185 that has 100 hours on it I noticed a sound that Im trying to determine what it is. I have never been in a boat with a bad gimbal bearing but that's my guess right now. The only time the noise is obvious is while in gear and at 1000rpm. That seems to be where it sits going through a no wake zone. While backing in or out at the dock and idling in gear, there is no noise. Anything above 1100 rpm is quiet also. Its a small range of RPMs that the whine noise is present. Its not very loud, but I'm familiar with the boat and never noticed it before this season. Over the winter I pulled the drive and checked the gimbal and it felt perfect. I also greased it the day it went in the water thru the zirc on the housing with mercury gimbal grease. I notice no vibrations or other symptoms that I can report. Anyone have any ideas? Only happens in drive and at around 1000rpm

Thanks in advance

 

[Boatguy49036]

The gimbal bearing will make the most noise when LU is turned/steering, even more tilted up and turning. It will be noisy all the time, in gear or not in gear. I’m not suggesting it’s not the bearing but in my experience, when a gimbal is shot, it’s just plain loud all the time.

 

[fwebster]

Besides, at 100 hours a gimble bearing isn't likely to fail unless you have a hole or tear in the bellows that lets water get to the bearing. When was the outdrive last removed for service?

 

[dieselsmoke]

Besides, at 100 hours a gimble bearing isn't likely to fail unless you have a hole or tear in the bellows that lets water get to the bearing. When was the outdrive last removed for service?

The outdrive was off during the winter. The boat was stored in an unheated facility (NJ), while the drive was in my garage. Bellows showed no signs of dryrot or leakage. The gimbal was smooth and quiet. U joints are not serviceable but were good. All new seals and drive oil, shaft was lubed up good and the drive was painted and reassembled.

I ran it pretty hard yesterday. (20ish miles, half tank of fuel, and mostly at 4000rpm) It made the noise going in and out of the marina but on the water it was absolutely perfect. Hope this helps

 

[BillK2632]

Well pretty sure it's not the gimbal bearing - really if it is greased properly and never get's wet it should last a long, long time. My boat still has the original gimbal bearing. Outdrives make noise, there are a lot of moving parts and the pitch of the sounds it makes will change as it is trimmed up/down and turned left/right.

I am assuming you have checked the obvious things, no water in gearlube, proper gearlube type and level?
One thing to check is the propeller - make sure the hub is not rubbing where it sits slightly inside the drive housing. Aluminum props especially are not always perfectly round there and it does not take much (ie a coat of paint) to have a slight rub. This will translate into a whine

 

[dieselsmoke]

The oil in the monitor is not milky or cloudy, It smells like it should and is the same level I filled it to. I used high performance quicksilver 90sae. Filled from the bottom until the vent leaked, closed it up, and then filled the monitor to the proper level still pumping from the bottom. It is the first time I ran this prop so that may be the culprit.

 

[searay205]

I don’t think you have any issue. Mine whines at exact same rpm. 5.0 mpi with alpha 1. I you tubed and found same sound on many. My guess is gear whine. If u had a problem you would know by now. Enjoy the boat. If u look hard enough you might very well create a problem. As far as not noticing before that what I thought when I heard mine. Then found old video of pulling kids on kneeboard. Sure enough noise was there

 

[dieselsmoke]

I don’t think you have any issue. Mine whines at exact same rpm. 5.0 mpi with alpha 1. I you tubed and found same sound on many. My guess is gear whine. If u had a problem you would know by now. Enjoy the boat. If u look hard enough you might very well create a problem. As far as not noticing before that what I thought when I heard mine. Then found old video of pulling kids on kneeboard. Sure enough noise was there

Great advice, Thank you, Enjoying the boat is the plan for sure!

 

[Stingrayaxe]

If you have the old prop you might want to try changing back. See if the sound goes away. If it does then you will know that it is related to the new prop.