Strut or Prop Shaft
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=20449
Printed Date: November-20-2024 at 8:45am
Topic: Strut or Prop Shaft
Posted By: flipflop
Subject: Strut or Prop Shaft
Date Posted: January-24-2011 at 2:27pm
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I spent a while checking my strut, prop shaft, and coupling alignment last week. I was able to quiet down the vibration significantly.
Here is more info if needed: http://www.correctcraftfan.com/forum/forum_posts.asp?TID=20267&title=transmission-mount--nut-size - old post I have a few pictures and wanted to hear your thoughts. I read this article on the site and found it very helpful. http://www.yachtsurvey.com/Alignment2.htm - yachtsurvey 
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Replies:
Posted By: 8122pbrainard
Date Posted: January-24-2011 at 4:27pm
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James,
It's always hard to tell from pictures if a strut is bent especially if it isn't a drastic bend. Holding the square up to a non machined surface doesn't tell much ether. However, I would say it does look like the strut is bent towards the starboard side. Getting back to your other thread when you were thrying to do a alignment, when you had the coupling halves unbolted, did the shaft seem "happier" (turn easier) when it was moved to one side? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: flipflop
Date Posted: January-24-2011 at 6:57pm
I figured as much, wanted to post for reference.
I was thinking the same thing. It is more noticeable in person.
Yes, just slightly easier to turn when moved a little to the port side. Everything looks really good for alignment. I'm within the .003 tolerance, the prop shaft is centered in the log hole, strut bearing has no movement up/down or left/right. When lubricated (soap + water) the shaft turns smoothly with two fingers all the way around. So maybe a slightly bent strut (to the right) or prop shaft before the strut? |
It's always hard to tell from pictures if a strut is bent especially if it isn't a drastic bend.Posted By: flipflop
Date Posted: January-24-2011 at 7:13pm
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Sure this boat has some problems and I can't fix everything (not sure if its feasible).
Thanks to help from the board, it starts turn key and is still put to use. Water is still cold, but on a sunny day its worth the trip. 
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Posted By: TRBenj
Date Posted: January-24-2011 at 7:34pm
You still dont seem to understand the purpose of aligning the drivetrain. You need to align from the strut forward. That means wherever the prop shaft spins freely in the strut is where the shaft needs to be. Move the engine to meet it. If that is a little towards the port side (instead of straight through the center of the shaft log) so be it. You dont force it to the center of the log and then dial in your (mis) alignment. The fact that your shaft is a little to the port side of the log when aligned properly in the body of the strut would indicate that your strut is either mounted slightly off, or is bent. You can either fix it or align to it- but dont ignore it and pretend that the strut is perfect by forcing the shaft to the center of the log. ------------- |
Posted By: flipflop
Date Posted: January-25-2011 at 12:51am
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TRBenj, I certainly am learning and have a much better concept of alignment now. I took your advice from the last post, unbolted my motor mounts and tried to push the engine over to the port side slightly to better meet the prop shaft coupler. I don't ignore the information that is posted. I really value your advice and follow what I can to the best of my ability.
With that said, I had a hard time moving my engine (if at all) and it may need to go another 1/8'' or 1/4'' to the port. Any tips on moving the engine? I used a jack under the exhaust manifold, but the mounts still wouldn't break free. However, I was able to get a good view of how the adjustments moved the transmission coupler and could see why my last attempt at alignment caused the vibration to get worse. I took the boat out for a test drive to monitor progress. The vibration isn't fixed, but it got a lot better from last time. |
Posted By: 8122pbrainard
Date Posted: January-25-2011 at 9:48am
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James,
Just as Tim mentioned, moving the engine isn't the answer if your strut is bent. Alingment starts at the strut. If you fell you need to move the engine 1/8" to 1/4" something is really off and it most likely is the stut. Besides, you may run out of room between the shaft and the log!! I suggest you pull the strut and we'll go from there. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: flipflop
Date Posted: January-25-2011 at 11:55am
| Sounds like a plan. I will research and follow up. Thanks. |