Shaft alignment – questions for the pros
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=36151
Printed Date: November-17-2024 at 5:59am
Topic: Shaft alignment – questions for the pros
Posted By: Furno
Subject: Shaft alignment – questions for the pros
Date Posted: May-26-2015 at 11:27pm
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I needed to replace the rubber isolater bushings in the rear motor mounts this year. The old ones were hard as rocks and starting to breakdown. I was able to get the old bushings out and the new ones in without much trouble. I figured this is a good time to check the alignment. Prior to this, I have not had any issue with vibrations, but since I was changing the bushings and the alignment had not been checked in years, I figured it was time. I watched Pete’s video the checked the strut alignment and strut bearing and it looked straight and tight. My question comes when re-connecting the coupler flanges. When the flanges are separated about a ½ inch or so, prior to the collar in the rear flange connecting with the front flange the two flanges do not line up.  When I line them up and move them closer to where the collar is lined up with the front flange, when I check the gap, it’s even all the way around. I rotated the flanges so they were in different positions and the gap always seemed to be consistent and even.  I don’t know if I was wasting my time, but with the flanges separated, I tried to get the flanges to line up by adjusting the mounts. For whatever reason, I could not get the motor to adjust from side to side. All the mounts moved freely and could be adjusted, but when trying to pry the motor to the side, it would not budge. I also made sure the loosen the bolts that allow the side to side adjustment. I loosened the mounts and was able to see the parts of the mounts that allow the side to side were free and not froze up. I ended up reconnecting the coupler flanges and did not need to make any adjustments. I’ve read some post that said it’s a good idea to remove the packing prior to performing the alignment, but I didn’t see that in Pete’s video. Also, I have not had the boat in the water yet this year, so could that have affected the alignment when the flanges are separated, or maybe when they are separated, it makes no difference at all. If anyone has thoughts or advise, it would be appreciated. Thanks, Andy ------------- Andy '83 2001 |
Replies:
Posted By: SNobsessed
Date Posted: May-27-2015 at 12:04am
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Andy - Does the shaft have any 'free play' left when you engage the pilot, or are you having to pull on it? It needs to have free play so that the strut bushing isn't loaded on one side. When you say the gap is even, are you using a feeler gage? If you measure accurately enough, it isn't exactly even, trust me on that. One trick is to make a support (a 2x4 with a v notch works OK) to hold the loose shaft in the middle of the 'free play ' zone so you can change the engine position to get close. Good luck. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: 8122pbrainard
Date Posted: May-27-2015 at 12:05am
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Andy, You haven't posted a picture of the log/hose/packing gland which would give a visual indication if the shaft is centered in the log. Remember alignment starts at the strut and then forward. The shaft needs to be roughly centered in the log and turn freely in the cutlass before you align the engine. Is it centered and still turns freely in the cutlass? The picture showing the shaft way off to port in relationship to the engine does tell me something is wrong. Continue investigating. You say the coupling flanges are even between them. What is the difference if any? .003" is max side to side and top to bottom. What did you check the difference with? Engine mounts can get real stuck. Some have even had to remove them one by one to free them up on the bench. Vibrations are snubbed by misalignment. Vibration is NOT a good indicator of alignment. ------------- /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: Furno
Date Posted: May-27-2015 at 12:55am
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Chris / Pete thanks for the replies. The shaft does have free play in it and it does not take much effort at all to get it inline with the front 1/2 of the coupler. Is that what you're asking? The shaft also turns pretty freely in the strut. I could not find my feeler gage, so I was using a flat small machinist ruler. It took roughly the same effort to insert it all the way around. (I recall in Pete's video he said the thickness was not important, but the variance was.) I'll be back at the cottage this weekend so I'll make sure I have the feeler gauges and I'll also take a picture of the log/hose/packing gland. I was actually surprised there was no play in the strut bearing. When I first separated the coupler and saw the free play at the coupler end I thought it seemed odd, but then when i checked the rotation and then went underneath to check for play, there was none. I still don't understand why I could not get the motor to move side to side when both the rear mounts were free. I loosened the bolts that attach them to the trans and the cradle and could see they were free. The fronts were not stuck either. I made sure I could loosen the lock nut and turn the adjuster bolt. More investigation this weekend. ------------- Andy '83 2001 |
Posted By: Furno
Date Posted: May-27-2015 at 12:58am
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One more question, should I remove the hose and packing gland to see how centered it is in the log or should I be able to determine that by how much side to side free play there is and if it's resting in the middle?. ------------- Andy '83 2001 |
Posted By: 8122pbrainard
Date Posted: May-27-2015 at 7:25am
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Andy, You may be able to see if the shaft is centered from the bottom of the boat. Do check it since I don't like the way the shaft moves to port when it's unbolted at the coupling. Chris mentions the block of wood with a V cut. That is an excellent method to hold the shaft in position while you get under the boat and check if the shaft rotates freely in the cutlass. The mounts are just rusted at the side to side pinch points. ------------- /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: SNobsessed
Date Posted: May-27-2015 at 9:38am
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Andy - You can put a small jack under the manifolds & hold up the rear of the engine while you remove the mounts to free them up. Try using some ATF & acetone mixed 50/50 as a penetrating oil, it works great. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: Sleepyone
Date Posted: May-27-2015 at 10:37am
| When you loosen the side to side nuts that hold onto the bolts make sure you leave the nut on the top few threads and lightly tap the top on the nut. this Bolt nut assembly will loosen as these bolts are taperd to hold against the side to side shafts on each side. they are not just a standard bolt with threads. So you have to unlock the taper by taping it down and the bolt will loosen and you can move it sisde to side . |
Posted By: Furno
Date Posted: May-31-2015 at 9:26pm
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So, after a very rainy weekend, I was able to get to the bottom of the motor not moving right to left. On the port side mount, I loosened the pinch bolt and then removed the whole mount. I knew it was not binding in the mount and proof of that was the two pieces feel apart when I got them out. (The pinch bolt fell out too because I had completely removed the nut, but that's another story.) After examining the mount to try and find out why the motor was not moving and not finding anything, I tried to move the motor without the mount in place and it moved right over with a little leverage. I then looked at the area where the mount bolts to the motor, and you could see a slight wear mark were the end of the round rod was just slightly touching the block. So I went back to the mount, and with the round rod pushed all the way into the receiving part, the rod stuck out about 1/4 inch. I then went to the bench and removed the about 1/2 of an inch, re-installed the mount and was able to move the motor to line up with the shaft side of the coupler. And yes, prior all this, I did re-confirm the strut seemed straight and the shaft was centered in the log. This was all Friday night and I still had not found my feeler gauges. A ran to the auto part store in the morning and was able to following the instructions in the video. Up and down seemed good, but with some adjusting I was able to get the .007 on one side and .009 on the other, but not the .010 so that's were I left it. I figured that's between .002 and .003. I was thinking I would run it a while and then re-check.. I store the boat on a hoist in the summer. Is there any problem doing the check on the hoist or even in the water? due to the rain, I was not able to water test, so that will be in 2 weeks. One more question about the rear mounts. Why are they only mounted on the top and the lower holes are not utilized. They also seem to be mounted about 1/8 inch away from the cradle. Seems odd, but I'm guessing there's a reason. . Has anyone heard of the mount rod hitting the block? After I was all done, with a light, I could see through a small relief in the mount that it was not touching the block. Andy ------------- Andy '83 2001 |
Posted By: 8122pbrainard
Date Posted: May-31-2015 at 9:49pm
Andy, If you got the .007 on one side and .009 on the other, that's a .002 difference and below the max of .003. I'm confused with the .010 you mention. Explain where you are getting that measurement. Eric, a member we haven't heard from in several years owned Fantastic Finish Marine. He specialized in marine trans rebuilding and in my opinion was/is the best in the country if not the world. Anyway, part of that business involves trans alignment. Eric always felt that trans alignment was best done with the boat in the water. I've never noticed a difference so I feel on the hoist is fine as long as its a bunked hoist. I'd be concerned if it was hanging by the lifting eyes. ------------- /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 < |
Furno wrote: