2004 Bayliner 185 chirping noise when going straight

[traumamed]

So I'm a little stumped here. I have an 04 Bayliner 185 with a 3.0 Mercruiser and Alpha One Gen II outdrive. Gradually over the course of one outing, it developed what I can only describe as a high-frequency chirp that echoes through the engine compartment so it is not easy to pinpoint. Here are the symptoms:

--Occurs both in gear (forward & reverse) and in neutral.
--Worst when going straight. Noise completely disappears when turning sharply in either direction while in the water, and mostly resolves when turning sharply out of water on muffs.
--There is no growl when turning sharply.
--The noise does seem RPM-dependent. It also seems to get quieter when accelerating or underway, but this is probably just because engine and wind noise drown out the chirp.
--Does not seem to effect boat performance in any way.

I have already checked the belt and all pulleys - these are definitely not the culprit. I figured they weren't the issue since the noise is steering-dependent, but I just wanted to cover my bases. What is really confusing me about this is that I thought gimbal bearings or U-joints typically made noises when they were under stress such as during a turn, not when going straight. Also, my boat is manual steering so there isn't a power steering pump to suspect. Bellows seem to be in good shape as the boat never has a drop of water in the bilge after a day on the water. Any suggestions on what I should look for when I pull the drive? Thanks for any help!

 

[alldodge]

So I'm a little stumped here. I have an 04 Bayliner 185 with a 3.0 Mercruiser and Alpha One Gen II outdrive. Gradually over the course of one outing, it developed what I can only describe as a high-frequency chirp that echoes through the engine compartment so it is not easy to pinpoint. Here are the symptoms:

--Occurs both in gear (forward & reverse) and in neutral.
--Worst when going straight. Noise completely disappears when turning sharply in either direction while in the water, and mostly resolves when turning sharply out of water on muffs.
--There is no growl when turning sharply.
--The noise does seem RPM-dependent. It also seems to get quieter when accelerating or underway, but this is probably just because engine and wind noise drown out the chirp.
--Does not seem to effect boat performance in any way.

I have already checked the belt and all pulleys - these are definitely not the culprit. I figured they weren't the issue since the noise is steering-dependent, but I just wanted to cover my bases. What is really confusing me about this is that I thought gimbal bearings or U-joints typically made noises when they were under stress such as during a turn, not when going straight. Also, my boat is manual steering so there isn't a power steering pump to suspect. Bellows seem to be in good shape as the boat never has a drop of water in the bilge after a day on the water. Any suggestions on what I should look for when I pull the drive? Thanks for any help!

:welcome: to iboats

Sounds to me to be your gimbal bearing. When you turn more load is placed on the bearing and pushes it to one side stopping the inner and outer races from moving. When it's straight, there is were the greatest wear is found and it starts slipping again.

Edit: When it's running on muffs, pump some grease in it and see if it quiets a bit

 

[traumamed]

Thanks for the quick reply AllDodge! I wondered with it being steering-dependent if it was just the gimbal bearing. It just seemed like the symptoms were "backwards" but your explanation clears that up. It will probably be a couple of weeks until I have the time to tackle this but I will be sure to post back with results. Fingers crossed it's just the gimbal.

 

[Bondo]

Thanks for the quick reply AllDodge! I wondered with it being steering-dependent if it was just the gimbal bearing. It just seemed like the symptoms were "backwards" but your explanation clears that up. It will probably be a couple of weeks until I have the time to tackle this but I will be sure to post back with results. Fingers crossed it's just the gimbal.

Ayuh,.... Welcome Aboard,... Grease it, 'n see if the noise goes away,.....

 

[traumamed]

Hi Bondo, I greased it with the green Mercruiser grease and had only mild improvement of the noise. Noise **might** have been a tiny bit quieter for a few minutes but that's it.

 

[alldodge]

Hi Bondo, I greased it with the green Mercruiser grease and had only mild improvement of the noise. Noise **might** have been a tiny bit quieter for a few minutes but that's it.

You need to pull the drive, no other way to tell

 

[traumamed]

You need to pull the drive, no other way to tell

As I expected. That's not too big of a deal, just need to make sure I pick a day when I have time to manage whatever I find when I get the drive off. I will update here in a couple of weeks when I get to it. Thanks again for your help.

 

[traumamed]

Just wanted to update in case anyone has a similar issue. I got around to doing the job today. Took outdrive off, inserted engine alignment tool, and noted a good deal of play (probably 2-3mm) once I had the alignment tool mated to the coupler. The play was where the tool went through the gimbal bearing. The bearing rotated freely but apparently the inner portions had worn or otherwise compressed. Replaced gimbal bearing and I am happy to report the noise is now gone. So there you have it - even though gimbal bearings are traditionally identified as going bad by hearing a growl when turning, apparently a gimbal bearing can also alert you that it is going bad by chirping when going straight. Hope this helps anyone who encounters a similar issue.

 

[alldodge]

Thanks for the update and glad your back in business