Mercruiser 3.0 engine alignment

markhodges78

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Aug 4, 2016
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423
Am I missing something. If you have full contact on the top of the tool, wouldnt you want to raise the front of the motor?
No by raising the front of the motor you would be lowering the back of the motor which would make more contact on top of the tool
 

Rick Stephens

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The pivot point is at the coupler. When you raise the front you get more relief on the top front of your alignment bar.
 

bruceb58

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Mar 5, 2006
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30,589
The pivot point is at the coupler. When you raise the front you get more relief on the top front of your alignment bar.
That is backwards. If you are contacting the top of the alignment tool, you need to lower the engine.
 

Rick Stephens

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Then what is left is pulling the front mount, getting alignment hanging off the lift and measuring what actual height needs to be on the structural crossmember or modifying the mount somehow.
 

Speak

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Jul 29, 2012
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467
Ok I understand the fundamentals of the alignment However, he has only changed the gimbal bearing and now has this problem. If things are this bad and have been all along then I would be closely taking a look at the coupler splines and rubber for wear. Is there a chance that the gimbal has been installed incorrectly causing all this trouble. Something is not adding up. Someone here has recommended that the bearing be seated by whacking all four sides. Has this been done? I feel as if the bearing is not sitting flush in the transom assemble. Just my 2 cents.
 

markhodges78

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Aug 4, 2016
Messages
423
Ok I understand the fundamentals of the alignment However, he has only changed the gimbal bearing and now has this problem. If things are this bad and have been all along then I would be closely taking a look at the coupler splines and rubber for wear. Is there a chance that the gimbal has been installed incorrectly causing all this trouble. Something is not adding up. Someone here has recommended that the bearing be seated by whacking all four sides. Has this been done? I feel as if the bearing is not sitting flush in the transom assemble. Just my 2 cents.

Ok the reason for the gimbal bearing change was because when I started it up this year there was vibration that I had not experienced before after I replaced the bearing is when I found out about the mounts you can set them side by side and see that they have pushed the rubber up about an 1/8 of an inch so new mounts where in order I believe that's what had caused this new vibration the boat has not run this season yet other then in the yard. ...

So today's update I put another washer under the rear mounts that's not as thick as the washers that's there now and now I can pull the tool out with two fingers and my grease marks are the same all way around. .. should I leave like this or modify the front mount. .
 

Rick Stephens

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Only way it can change is the rear mounts are bad or the transom is so bad the back of the motor is settling. Doesn't make sense to me.
 

achris

More fish than mountain goat
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May 19, 2004
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27,468
...So today's update I put another washer under the rear mounts that's not as thick as the washers that's there now and now I can pull the tool out with two fingers and my grease marks are the same all way around. .. should I leave like this or modify the front mount. .

OK, there are 2 different mounts. The old style required the 'special washer' under it. The one that looks like a double wound spring. They were replaced about 10 or so years ago by a revised mount that has a longer centre section, and DOES NOT require the special washer. If you have the new style mounts in and put the special washer as well, it will give the impression of the front being too high.

What is the part number of the new mounts?

Chris........
 

markhodges78

Chief Petty Officer
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Aug 4, 2016
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423
The new mounts are 865329A02 I did not use the double wound springs I used the the steal washers that came with the kit. I also added a washer on each side that are about 1/16 inch thick that allowed me to get proper alignment I do belive I front mount is to high and came that way from the factory so the? Is to leave it as it is or modify the front mount
 

achris

More fish than mountain goat
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May 19, 2004
Messages
27,468
If you have a good alignment at each 90 degree interval, then I would leave it. Just be sure the tool is going in all the way.
 
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