Mercruiser Engine Alignment (Solved) after 7 days

7 Days of trying to get the engine / gimbal bearing / lower unit aligned...
Solution, use a winch on the front motor mount and start with large corrections.
1970 Glastron with 120hp mercruiser
In the Summer of 2021, gimbal bearing overheated, and basically was stuck to the drive shaft U-Joint, I had to cut it off. That fall had a very difficult time getting the lower unit back on, even after trying my gimbal bearing trick (see video...)
Spring 2022 we tested out the boat and there was an bad clunking noise.
We pulled the lower unit, replaced the U-joints / gear set with a spare.
Pulled the engine, put in new motor mounts.... Did not press them in far enough, pulled the engine again, repressed the rear mounts. Replaced the engine coupler
Installed everything and we could not get the alignment tool to go in easily or come out with out pressing down on the tool..... After many many attempts of adjustment, heaving with the tool.... Still could not get the alignment tool to go in by pressing with one finger.
Solution:
Bolt in the rear mounts, loosen the front mount.
Use a crane / cherry picker / hoist to raise the front of the engine until you can NOT push in the alignment tool (thus you know 100% you are too high in the front).
Then start to lower the front of the engine and test with the tool until you can push in the tool with one finger, and rotate the tool with two fingers.
Tight the front mount, re-test and adjust as necessary.
Once we did that we were able to get the lower unit in place.
On this boat the motor mounts were 52 years old.
The engine coupler had two loose bolts which is what I think caused the entire problem.
The boat is in the water and runs great.
I have a second video showing the lower unit installed.
It took us a few attempts to push the driver shaft through the gimbal bearing to the two rubber o-rings on the drive shaft.
Part 2 URL: • 1970 Mercruiser, fina...
-andy

[@mccarterjg]

My god there must have been 20 other videos of people saying this is how you do an alignment for your gimbal bearing, 2 minute videos and not a single one of them showed how they got to the finished product, I got the forklift hooked up now

[@theOriginalBanger]

Let us know how it worked out!
-andy

[@scottsmith2869]

Great video! I too am using this method! But when I get in the boat to lock down the engine mount nuts, my weight caused the boat to move down and I was always locking it down at the incorrect spot. Now I will put jack stands under the trailer to keep it all in place. Hope this helps.

[@theOriginalBanger]

Good idea about using jack stands to stabilize the boat/trailer!
-andy

[@wphun]

You do good work. Regular Joe stuff