Mercruiser 350 Alignment Issues

[lmorefield41]

Ok, on to my next can of worms. I've recently had to rebuild my engine mounts as they were rotted in my 83' Wellcraft Nova. I was actually out in the channel and the engine dropped through the glass and mounts, stripping the splines in the coupler smooth. As a result, I pulled the engine, rebuilt it and was able to get it started (figured I might as well since I had it out of the boat), I also rebuilt the engine mounts as they were literally dust.

Once I got all of the crap cleaned out, I checked the stringers, which were glassed separately and have no signs of rot or decay or weakness whatsoever, so the mounts were all that needed rebuilt. The condition of the mounts were so bad that I was not able to get accurate measurements so that when I rebuild it would be a mirror image. When reconstructing, I gave myself room to move the front mounts up, not down, as going down would mean that I have to start shaving inches off of the already built and glassed mounts. I got each mount within half an inch of the original mounts.

My problem is that I've been fooling with this thing since the 4th (Thursday), and I'm still not able to get my alignment tool to insert the coupler. I've adjusted each mount an 8th of a turn from bottomed out until as high as it will go, and I've still not been able to insert my alignment tool into the coupler at all, not even a mm. I've searched and searched the forums, however, I've not been able to find an issue that exactly like this. The only post that I've been able to find that has any similarity, the guy was able to insert his tool 1/2 inch into the coupler.

 

[Bt Doctur]

Re: Mercruiser 350 Alignment Issues

what hardware was used for the rear mounts? Worst case is to support the motor just from the front, remove mounts, and use a hoist to raise or lower the motor untill tool fits.

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

On the rear mounts, I have the fiber washer with the lock nut inside of in on the transom mount, then the actual flywheel housing laying flush, then the spacer, then the washer, then the bolt torqued at 45 lbs. Like this diagram. I've also been adjusting it both by bolts and by a hoist, it almost seems as if the engine is too high in the back where the rear mounts go, which is impossible because nothing changed there. It feels like the tool has to go up then in. If the gimbal bearing moved, how do I get it back in place without the tool going into the coupler?

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

After thinking about what happened regarding the engine dropping, I'm sure that the gimbal bearing adjusted as the engine dropped, causing the shaft to drop as well skewing the angle of the bearing. I remember it was hell trying to get the damn outdrive off in order to pull the engine as the shaft was at about a 45 degree angle downward inside of the coupler still. Should I replace this gimbal bearing?

 

[Don S]

Re: Mercruiser 350 Alignment Issues

Turn the bearing, if it's not perfectly smooth, replace it.

You do understand the inside portion of the bearing actually "gimbals" in the carrier (outer ring). It doesn't move easily and you have to use some force with the alignment bar to move it, but you may have to do that to align the gimbal bearing to the coupler, then you do the final alignment of the engine to the alignment bar.

I usually get the gimbal bearing roughed in until the bar can be pushed in at least halfway into the coupler and with a rubber mallet bump the alignment bar up and down, and side to side in order to "Set" the gimbal bearing in it's carrier.

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

I usually get the gimbal bearing roughed in until the bar can be pushed in at least halfway into the coupler and with a rubber mallet bump the alignment bar up and down, and side to side in order to "Set" the gimbal bearing in it's carrier.


View attachment 201933

Got ya, I knew about bumping it each way once it's in the coupler, just didn't know how to set it before I get the tool to enter the coupler. I'll go try to move it around until I can get a bit of the tool into the coupler. Update you in a few.

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

Ok, was able to move the gimbal bearing enough to where 1/2 inch of the tool is going in. Once I had the tool in, I hammered each way like the manual says to. I had thicker more defined spline marks on the top and lighter on the bottom. Just to be 100% sure, which way do I start adjusting the front? Up or down? I don't want to screw it up, it's taken me days to reach this breakthrough, lol. I almost gave/give up and want(ed) to take it to a Marina to get robbed but to get it done.

 

[Don S]

Re: Mercruiser 350 Alignment Issues

Heaviest marks on to of the alignment bar means you need to bring the front of the engine down.

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

Heaviest marks on to of the alignment bar means you need to bring the front of the engine down.

Thanks for the info because I was trying to figure it out and actually had the opposite thought in mind and would've executed it that way had I not asked. I'll keep you guys updated, thanks for all the help.

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

Ok, so I have the spline marks even all around, however, I can only get the tool in up to an inch, it hasn't been in farther than an inch yet, it feels as if it bottoms out and that's it. I gave a little pressure (not enough to harm anything) to see if it would budge and it did nothing.

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

Ok, I have it all the way in now, however, I have to give it pressure to get it to bottom out. I keep adjusting and adjusting, but I believe it's a port/star mount issue now, not so much an up and down issue. With the original mount beds being in such bad condition when the engine dropped, I wasn't able to rebuild exact replicas of the originals. I do know that they were a few inches different in height, and so are the ones that I just built, as I tried to follow the originals as best as I could. Any advice on what my next moves are?

 

[Don S]

Re: Mercruiser 350 Alignment Issues

With the bar all the way in, bump the bar again all around with the mallet.

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

With the bar all the way in, bump the bar again all around with the mallet.

I have, just sturdy taps though. Am I supposed to pound it like whack a mole? Lol. I'm getting skewed spline results as well. It looks like the right side of the tool has the deep marks and the rest of the tool are evenly light.

 

[Don S]

Re: Mercruiser 350 Alignment Issues

You aren't trying to bend the bar, just "shock" the bearing so it stays in place. Never whacked a mole, so can't say yes or no to that.

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

Just turned the engine and had to give a lot of force to get it to go past the 1" point and bottom out. Hit the bearing again. I've dropped the engine pretty substantially through the front mounts since I've started. I've been at it non stop for the past few days and I've made a ton of progress today, but I just feel like something else is off. The spline marks are different almost every time I lower or raise, and I believe there's an issue with the port/star mount height.

 

[Don S]

Re: Mercruiser 350 Alignment Issues

If you turn the engine and the alignment changes, then you either have the coupler installed with some dirt or rust under one side, or the coupler is bad. The alignment shouldn't change as you rotate the engine.

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

Ok, so I aligned the engine to where the spline marks were equal and I could pull it out with my thumb, index, and middle finger, then turned 90 degrees, had to do some adjusting, got it to where it was easy that I can pull it out with my thumb, index, and middle finger, turned it 90 degrees, now it won't go in farther than the 1" point again.

If you turn the engine and the alignment changes, then you either have the coupler installed with some dirt or rust under one side, or the coupler is bad. The alignment shouldn't change as you rotate the engine.

It changes so much that I have to adjust the mounts up to 3 full turns on each side. There shouldn't be any rust on the coupler as I cleaned it throughly and removed and painted the flywheel. Here's a video of me starting it on the ground, the coupler doesn't seem to be moving oblong or anything like that, not sure if you can tell from this or not. 1983 Mercruiser 350 5.7L Ground Start - YouTube

 

[lmorefield41]

Re: Mercruiser 350 Alignment Issues

After 1000 adjustments, literally I bet, I've reached equal results when turning the engine every 90 degrees. I have one last question regarding this, what does it mean to have a cocked engine? My boat is currently in my driveway which is slanted at about 45 degrees, the back of the boat is towards the house which is at the top of the slope. It's probably not a good idea to start it like this right? I'm getting ready to tighten the mount bolts, wish me luck that they don't adjust.

 

[Dogdave]

Re: Mercruiser 350 Alignment Issues

I had a very similar issue. The guy that did my glass work ( that I should have done myself ) had the mount pads off angle and when I torqued the top mount bolts it pulled up on the rear mount messing up the spline alignment. I raised the engine and cut hardwood shims ( long story short) bolted it down and off I went.