Alignment Question

[CFM56-7]

I'm slowly progressing though all the work that needs to be done to get my recently purchased Ebbtide ready to go for next season. I need some more expert advice.

When I pulled the drive, I knew the alignment was way off based on how difficult it was to pull the driveshaft out. I confirmed that with an alignment rod which bind up before even going into the splines. After lowering the front mount as low as it goes, the alignment rod goes in and out fairly easily, but the grease test reveals it could go down even farther.

I have NOT yet rotated the engine to confirm the coupler is true, but I have a few questions to see how bad this could be.

--Is running the front mount as low as it goes a potential problem long term?

--Could the fiber washers or any other rear engine mount component be worn sufficiently to cause this condition?

--Long term, if the alignment is not absolutely 100% perfect, will that significantly shorten the life of the new gimbal bearing?

The old gimbal bearing wasn't making any noise but it feels just a little gritty so I will be replacing it. I can't imagine the new gimbal bearing will change alignment all that much. Also, the PO claimed the boat was difficult to start and had been for many years. I did run it twice before winterizing and it sounded like it started on two or three cylinders before smoothing out after a few minutes. I am quite confident I have remedied this condition, but the engine would rock side to side several inches during these rough starts. If this has been going on for years, I am wondering if this would have had an adverse affect on how the engine sits too.

Thanks for the input!

 

[agallant80]

Re: Alignment Question

--Long term, if the alignment is not absolutely 100% perfect, will that significantly shorten the life of the new gimbal bearing?

I can't answer your other questions but I know that if you run misaligned for long enough yes you can and will destroy the gimble but even worse you will destroy the coupler on the back of the motor which costs about $500 for the part and requires pulling the motor to replace. I would not use the boat until the alignment is correct.

 

[alldodge]

Re: Alignment Question

I'm slowly progressing though all the work that needs to be done to get my recently purchased Ebbtide ready to go for next season. I need some more expert advice.

When I pulled the drive, I knew the alignment was way off based on how difficult it was to pull the driveshaft out. I confirmed that with an alignment rod which bind up before even going into the splines. After lowering the front mount as low as it goes, the alignment rod goes in and out fairly easily, but the grease test reveals it could go down even farther.

I have NOT yet rotated the engine to confirm the coupler is true, but I have a few questions to see how bad this could be.

--Is running the front mount as low as it goes a potential problem long term?

No, the lowering of the mount will not cause long term problems, but this could be telling you there are stringer or transom problems. Does the front mount look like it has been repaired? If it has it could have been built up do to wood becoming soft and was not realigned.

--Could the fiber washers or any other rear engine mount component be worn sufficiently to cause this condition?

I don't see a fiber washer issue, but transom could be the issue

--Long term, if the alignment is not absolutely 100% perfect, will that significantly shorten the life of the new gimbal bearing?

The old gimbal bearing wasn't making any noise but it feels just a little gritty so I will be replacing it. I can't imagine the new gimbal bearing will change alignment all that much. Also, the PO claimed the boat was difficult to start and had been for many years. I did run it twice before winterizing and it sounded like it started on two or three cylinders before smoothing out after a few minutes. I am quite confident I have remedied this condition, but the engine would rock side to side several inches during these rough starts. If this has been going on for years, I am wondering if this would have had an adverse affect on how the engine sits too.

Thanks for the input!

Your gimbal and coupler will take the brunt of misalignment. The rocking of the engine may also be telling you something is worn or loose. If the engine sat long enough in one position and misaligned it could be the coupler now has a set and may need to be replaced. If it has developed a set then at least your stringers and transom should be OK

 

[CFM56-7]

Re: Alignment Question

If I get a narrower wrench, I'm sure I can get another turn or two out of it. My wrench was binding up between the mount and the washers above the nut. I just wanted to ensure running it bottomed out wouldn't be a problem before I went any further.

Everything appears to be original on the boat, but I have little experience so that may not be the case. Also, everything feels quite solid back there. The engine rocking back and forth was within the limits of the rubber mounts as I could detect no metal on metal contact. Also, the engine is quite firm in the mounts. I can't see any detectable movement throwing my body weight into it in either direction.

I'm new to all this fun boating stuff, but the engine mounts directly to the transom plate, right? The gimbal housing bolts to the transom plate too right? If all that is bolted together, even if I had soft wood on the transom, wouldn't the gimbal orientation remain fixed if it's all bolted together?

Thanks again for the responses! I'm out of town for the next several days, but when I'm back, I'll see if I can get the front mount down just a bit further to perfect alignment. I'll also spin the motor to ensure the coupler is true.

One more addition: The rocking of the engine back and forth was due to an incorrect choke setup and at least one faulty spark plug wire. Once things warmed up, she ran very smoothly. It was just the first maybe minute or so that it would be rocking back and forth. Once warm, she would also start right up with no side to side movement detected.

 

[alldodge]

Re: Alignment Question

If I get a narrower wrench, I'm sure I can get another turn or two out of it. My wrench was binding up between the mount and the washers above the nut. I just wanted to ensure running it bottomed out wouldn't be a problem before I went any further.

Everything appears to be original on the boat, but I have little experience so that may not be the case. Also, everything feels quite solid back there. The engine rocking back and forth was within the limits of the rubber mounts as I could detect no metal on metal contact. Also, the engine is quite firm in the mounts. I can't see any detectable movement throwing my body weight into it in either direction.

I'm new to all this fun boating stuff, but the engine mounts directly to the transom plate, right? The gimbal housing bolts to the transom plate too right? If all that is bolted together, even if I had soft wood on the transom, wouldn't the gimbal orientation remain fixed if it's all bolted together?

Thanks again for the responses! I'm out of town for the next several days, but when I'm back, I'll see if I can get the front mount down just a bit further to perfect alignment. I'll also spin the motor to ensure the coupler is true.

One more addition: The rocking of the engine back and forth was due to an incorrect choke setup and at least one faulty spark plug wire. Once things warmed up, she ran very smoothly. It was just the first maybe minute or so that it would be rocking back and forth. Once warm, she would also start right up with no side to side movement detected.

Look forward to hearing what you find. Before you go down any further try rotating the engine to see if you need to go back up.

If the transom was soft the geometry would change and while having the alignment correct when installing the drive, it being soft would cause things to move and put more load on one side of the gimbal. Not saying this is the issue just trying to figure out what you have and trying to rule out other possibilities. Either way something has changed to need to move the front all the way down, personally I hope it's the coupler or someone rebuilt the fiberglass on the front mount. The coupler will cost the most but much easier to fix then other things, but if it was a repair you should be good.

 

[84EdH]

Re: Alignment Question

The rear mounts have pressed in rubber sleeves that can sink in the rear mount transom plate arms. Along with the other possible problems, this would require the front of engine to be lowered to align. Also spring washers can sag with wear to same effect.

 

[CFM56-7]

Re: Alignment Question

This was my initial suspicion, but was looking for confirmation. I will still rule out the engine coupler as a potential cause of this problem, but the boat is 23 years old and the stress on the mounting hardware associated with the rough starting engine made sense to me as the probable cause.

If I can rule out all other possibilities, could this be remedied by simply adding a washer to raise the engine back close to the previous height or is the fix more complex?

 

[84EdH]

Re: Alignment Question

The rear bushings would need to be replaced if found to have sagged. Plenty of threads about how to do this.

 

[wrench 3]

Re: Alignment Question

They say that the alignment is satisfactory when you can pull the alignment tool back out with your thumb and index finger.

 

[tinkerguy70]

Re: Alignment Question

They say that the alignment is satisfactory when you can pull the alignment tool back out with your thumb and index finger.

This is correct. Once aligned, the tool will slip in and out with very the index finger and thumb.

Trust me.
If you run the boat with the engine out of alignment for any length of time, I can guarantee you it will destroy your coupler in short order. I speak from experience.

If you smoke the coupler, the drive will have to be removed, then the engine. I'm thinking it was around $200 or so for the new coupler. I did my own work, so I didn't have a repair bill.
You'll have to figure out why you are bottomed out on the adjustment before you proceed any further. Once that is fixed you can align the engine.
I'm not trying to scare you or anything, just trying to save you some money

 

[littlebookworm]

Re: Alignment Question

You do have to do some more investigating. The rear bushings and double-wound lock washers could very well be bad after 23 years. Would they be bad enough to require the forward mounts be down to the bottom adjustment? Maybe. Your problem might be caused by that, by bad stringers, or by a bad transom. Look for any signs that the transom mount has shifted at all or that there is some transom rot. Removing the rear mounts can be difficult. The last time I did that, on a 25-year-old cruiser, I had to drill out the stainless steel rear mounting bolts, quite a job. Hopefully you won't have to go through that. Start checking all the mounts. Good luck, and let us know the outcome, please. Hy

 

[CFM56-7]

Re: Alignment Question

Well, I checked out the boat after getting home today to see if I could gain some additional insight into my issue. The rear port engine mount is missing at least the fiber washer. The starboard fiber washer is installed, but I cannot confirm if either side has the double wound lockwasher installed. This leaves a noticeable difference in the spacing between the engine mount and transom plate when comparing the port and starboard sides.

Given the attention to detail and quality of work associated with the engine reinstall, I'm sure I'll be pulling the engine at some point in the future to remedy whatever issue the PO attempted to remedy.

The coupler is true and there is absolutely no evidence of any structure being anything less than sound. Also, there is no indication anything has shifted on the transom. I am convinced the missing component(s) are the sole cause of the alignment troubles and will be remedied shortly. Now I just need some guidance.

--Can I just use a scissor jack placed on wood blocks in the bilge area of the hull under the engine to jack the rear portion of the motor up half an inch to replace the double wound lockwasher and fiber washers on both sides? The coupler housing looks beefy enough on the bottom, just not sure if the hull would support such a load.

--Do I need to replace the engine mount nuts and bolts as well or can those be reused?

Thanks again for all the input! The expertise here is an invaluable resource.

 

[84EdH]

Re: Alignment Question

First take the drive off. If you jack the engine up even that much you will damage drive shaft. Don't jack under coupler. Get under edge of bell housing by the engine block. (Not under oil pan. Also, disconnect exhaust.

Its ok to reuse bolts and nuts.

Make sure you take top nuts off front mounts

 

[CFM56-7]

Re: Alignment Question

Thanks 84EdH, I ordered the washers this morning and will install them as soon as I get them in hand per your instructions.