| Author |
Message |
    
John McGrath
Member
Username: johnkillcare
Post Number: 8
Registered: 04-2008
| | Posted on Tuesday, April 29, 2008 - 08:14 pm: | 
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Thanks for all your advice guys, this is a great forum. I have only had my new (2nd hand) boat out 4 times so I am still getting to know it. I have no problems with the engine side of things as I am a car mechanic, but I have had no experience with the outdrive. My question is regarding a noise in the outdrive. When the engine is reving over 2000 RPM there is a high pitch whining noise from the outdrive, it is not overly obtrusive, sounds kind of like the noise a supercharger on a car motor makes (quite a pleasant noise actually) It makes the noise if it is nuetral or drive, the noise doesn't alter if the steering is straight ahead or turning and there is no grinding or knocking noises. The receipts I got with the boat say the gimbal bearing and all the bellows were replaced 3 years ago. It is an Alpha 1 gen 1 outdrive. Is it normal for the outdrive to make this noise or is it something that needs attention, I just want to make sure it is ok.
John |
Rod Stewart
Senior Member
Username: rod_stewart
Post Number: 1204
Registered: 08-2006
| | Posted on Tuesday, April 29, 2008 - 11:26 pm: |
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Audible whining is not usual to my knowledge (unless of course your wife or girlfriend is on board! But we digress...)
Are you sure it is coming from the drive?
You should get back there with someone else at the helm and see if you can localize the noise more closely. If it has power steering, it could be the steering pump. Or the alternator, or water circ pump bearings.
If its definitely the drive, it might be gears. How is the drive oil level?
You may want to take your local boat dealer mechanic for a ride and let him hear it.
Rod |
John McGrath
Member
Username: johnkillcare
Post Number: 9
Registered: 04-2008
| | Posted on Tuesday, April 29, 2008 - 11:53 pm: |
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The noise is definately coming from the drive area (I can even hear it over the top of the wife's whining) I'll get a stethascope next time I have it running and see if I can localize the exact area, if that fails I'll take your advice and get it up to the marine mechanic to listen to.
John |
Rod Stewart
Senior Member
Username: rod_stewart
Post Number: 1208
Registered: 08-2006
| | Posted on Wednesday, April 30, 2008 - 12:12 am: |
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John;
If its definitely the drive you might be well advised to have it checked out ASAP. That noise can't be good, and if the upper gears and or bearings are trashing, the metal bits will get into the lower gearcase and trash those gears and bearings too. The input shaft bearings may have the wrong preload, which again will lead to short life and major grief.
What I am saying is the longer you run it with gears or bearings that are wearing out the more expensive it will be to fix. (Then the wife will really be whining!)
Rod |
John McGrath
Member
Username: johnkillcare
Post Number: 10
Registered: 04-2008
| | Posted on Thursday, May 01, 2008 - 08:48 pm: |
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Just took the top cover off the upper gear housing, the outer bearing race of the top bearing is pitted and worn so I figure this is where the whine is coming from, likely the lower bearing will be in the same condition. Looks like I'm going to have to fit new bearings to the upper gearbox. |
Rod Stewart
Senior Member
Username: rod_stewart
Post Number: 1230
Registered: 08-2006
| | Posted on Thursday, May 01, 2008 - 10:59 pm: |
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That is quite inexpensive if that is all it is. Make sure you check the input shaft bearings as well, and replace if in doubt at all. Set the preload correctly.
Have a close look at the upper gear set for any sign of pitting or checking in the wear areas.
Sounds like you may have dodged a much more expensive touch by getting after it now.
Rod |
Guy Gaspar
Senior Member
Username: guyjg
Post Number: 1951
Registered: 08-2006
| | Posted on Friday, May 02, 2008 - 06:16 am: |
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Rod et al:
I wonder if water intrusion caused the pitting of the races? |
Rod Stewart
Senior Member
Username: rod_stewart
Post Number: 1236
Registered: 08-2006
| | Posted on Friday, May 02, 2008 - 12:15 pm: |
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Likely condensation pitting or perhaps lack of oil may have started it all, but who knows?
Rod |
chris
Member
Username: terrapin24h
Post Number: 25
Registered: 01-2008
| | Posted on Friday, May 02, 2008 - 04:12 pm: |
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worn orings and a leaky bellows somewhere in the past maybe? |
John McGrath
Member
Username: johnkillcare
Post Number: 11
Registered: 04-2008
| | Posted on Saturday, May 03, 2008 - 05:22 am: |
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That's the problem with buying anything second hand I suppose especially when you don't know the history. I did hear the noise when I tested the boat before I bought it but not having had a stern drive before wasn't sure whether it was a normal noise, it didn't sound nasty. Oh well I got it for a good price so it's not the end of the world. I'm just going to have to learn how to overhaul an Alpha outdrive!! |
Rod Stewart
Senior Member
Username: rod_stewart
Post Number: 1239
Registered: 08-2006
| | Posted on Sunday, May 04, 2008 - 09:31 pm: |
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Good luck on the project.
You should likely get yourself a decent manual if you are going to take a run at it yourself.
There is some important stuff that you will want to know about.
Rod |
John McGrath
Member
Username: johnkillcare
Post Number: 12
Registered: 04-2008
| | Posted on Monday, May 05, 2008 - 01:48 am: |
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Thanks for the advice Rod, yep I've got a good manual, wouldn't attempt the job without one, even though I'm a mechanic I've never touched a sterdrive unit before. |
Todd Moore
Advanced Member
Username: concritter
Post Number: 139
Registered: 12-2007
| | Posted on Monday, May 05, 2008 - 06:53 pm: |
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John,
To me you are a VERY good mechanic.A mechanic by trade,manual in hand and not afraid to ask questions to those that have seen these parts before to make sure things are correct.Hang close to Guy and Rod's advice and you will do just fine...Todd |
