I have definitely messed my shaft alignment up by torqueing down on the mounting nuts! Upon reaching 1400 rpm she cavitates. Here I was thinking I was doing the right thing and apparently I set it off. Acutally one bolt was missing, which I thought strange so I simply replaced it and tightened it down. I ran a thread several weeks ago, with great responses on how to rectify the problem; however, as I ponder this, could'nt the alignment be better adjusted while the engine is running? Crazy? This would violate every safety procedure in the book hanging over an engine with socket in hand loosening here, tightening there while a fan belt is rolling, but I have to say that I have very easy accessbility to all four mounts and with a 15/16 inch deep socket, 1/2 drive maybe that might be the ticket and work up on the rpms as I go. I already know the mounting bolts are not frozen and can be loosened easily. So, has anyone ever tried doing this? Your comments either encouraging or not are welcomed. Thanks Bob Catalina 30 M-18 Universal
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Scary
You have already answered the question, by mentioning all of the safety problems. All sorts of unpleasant or dangerous problems are awaiting you if you proceed. Please do not to this.
You have already answered the question, by mentioning all of the safety problems. All sorts of unpleasant or dangerous problems are awaiting you if you proceed. Please do not to this.
Maybe Removing the Belt Helps
I was not thinking about just removing the alternator belt, thereby removing any hazard. That might change things for the better. If we minimized the overall safety issue (heat, rotational apparatus, etc), is it still conceivable to adjust mounts underway? Bob 30 Catalina '88
I was not thinking about just removing the alternator belt, thereby removing any hazard. That might change things for the better. If we minimized the overall safety issue (heat, rotational apparatus, etc), is it still conceivable to adjust mounts underway? Bob 30 Catalina '88
Shaft alignment.
I'm sorry I didn't read you previous thread, but I think shaft alignment is the process of adjusting the engine position to ensure that the couplers of the engine and the shaft are parallel, within .003 inch. I don’t understand how you could check this with the engine running. Normally the coupler bolts are removed and a feeler gauge is used to see if the faces of the coupler flanges meet up squarely. I must be misunderstanding you. Now if you’re really inquiring about centering the shaft in the stern tube, than that’s a different matter. The only way I’ve heard to do this is to visually check the centering. You might have to remove the packing gland to do this? I still don’t see how having the engine running would be of any benefit. Fell free to straighten me out
The link below has a discussion even though he's talking about power boats.
I'm sorry I didn't read you previous thread, but I think shaft alignment is the process of adjusting the engine position to ensure that the couplers of the engine and the shaft are parallel, within .003 inch. I don’t understand how you could check this with the engine running. Normally the coupler bolts are removed and a feeler gauge is used to see if the faces of the coupler flanges meet up squarely. I must be misunderstanding you. Now if you’re really inquiring about centering the shaft in the stern tube, than that’s a different matter. The only way I’ve heard to do this is to visually check the centering. You might have to remove the packing gland to do this? I still don’t see how having the engine running would be of any benefit. Fell free to straighten me out
The link below has a discussion even though he's talking about power boats.Still scary
No! It is unsafe to both you and to the boat to attempt alignment with the engine running. Do not do it!
No! It is unsafe to both you and to the boat to attempt alignment with the engine running. Do not do it!
Right, it is adjusting the engine
To get to the .003 tolerance all around the coupler requires the adjustment of the engine. My adjustment was perfectly fine until I decided to tighten down the engine mounting bolts that hold the engine to the mounting brackets. I will not have to move the engine, only loosen or tighten the mounting bolts, which are not rusted. It may well be as simple as removing the missing bolt I added to gain back the alignment. If the shaft can be aligned by simply loosening or tightening the mounting bolts, then doing it while the engine is engaged just at the point when the vibration starts (1400 rpm) will yield either more increased vibration or make for improved alignment. It can help to identify which bolt is the culprit. As for safety, access to the mounting bolts is very easy. The 30 Catalina engine (M18)is mounted amidships with all four bolts visible and accessible from the top. I would not dare try this if it were a stern mounted engine and body contortions were necessary! Bob
To get to the .003 tolerance all around the coupler requires the adjustment of the engine. My adjustment was perfectly fine until I decided to tighten down the engine mounting bolts that hold the engine to the mounting brackets. I will not have to move the engine, only loosen or tighten the mounting bolts, which are not rusted. It may well be as simple as removing the missing bolt I added to gain back the alignment. If the shaft can be aligned by simply loosening or tightening the mounting bolts, then doing it while the engine is engaged just at the point when the vibration starts (1400 rpm) will yield either more increased vibration or make for improved alignment. It can help to identify which bolt is the culprit. As for safety, access to the mounting bolts is very easy. The 30 Catalina engine (M18)is mounted amidships with all four bolts visible and accessible from the top. I would not dare try this if it were a stern mounted engine and body contortions were necessary! Bob
OK
So want to get the engine vibrationg and then start randomly turning bolts until it smooths out. I wish you luck, but it sounds kind of tricky to me. When you adjust the mating of the flanges with the bolts out using a feeler gauge you can at least see which way the engine needs to be moved. Not sure how you'll know that with the engine running method. I found your previous thread, but I didn't see if you had tried the conventional method first.
So want to get the engine vibrationg and then start randomly turning bolts until it smooths out. I wish you luck, but it sounds kind of tricky to me. When you adjust the mating of the flanges with the bolts out using a feeler gauge you can at least see which way the engine needs to be moved. Not sure how you'll know that with the engine running method. I found your previous thread, but I didn't see if you had tried the conventional method first.
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