Engine/Prop Shaft Alignment

[Griff]

We just launched on Saturday the Ericson 29 we purchased last Fall. The boat had been on the hard for two years so I hired a mechanic to check over the engine prior to purchase. He determined that the engine was in good shape but he found that one of the prop shaft coupling bolts was missing. He told me at the time that the engine/prop shaft alinement should be checked after the boat was back in the water. It is a busy Spring here in Michigan for mechanics and I am having difficulty finding one to do the alinement check. One guy wanted $600 cash to do the job.

I am new to boat ownership but I have an average mechanical ability. I understand the need to have the prop shaft and the engine in alinement to .003. Is this a procedure that I can perform and could one of you knowledgeable gentlemen list the steps to be followed in checking the alinement? I have a Yanmar 2GM20F engine. We really would like to get out and do some sailing. Thank you in advance for any advice you can offer.
Kevin
79 Ericson 29
Lake Michigan

 

[bgary]

I've never done it, but...

...a number of books seem to have a good description of the process.

Calder's "Boat Owner's Mechanical and Electrical Manual"

Casey's "This Old Boat" or "Complete Sailboat Maintenance Manual"

 

[Frank Langer]

Kevin,
It is definitely possible to align the engine yourself. I would never spend $600 or even $100 to have this done, unless you have other problems. There are lots of sources for information on how to do this. Mainly you need a few hours time, lots of patience, and a couple wrenches. I hope you can figure it out--it is important to get it right to avoid damage to your cutless bearing, minimize engine vibration, etc.
Frank

 

[toddster]

Well, I wouldn't pay anybody $600. But it all depends on what your time is worth to you. I don't know how the Yanmar fits into the E29, but there is Very Little Room to work with behind the Atomic 4. IIRC, about an hour of painstakingly tiny movements of an Allan wrench while laying in a contorted position, just to get the coupler disconnected. After all that, I'm not sure why I didn't just cut out a larger hole in the back and work through the battery compartment side.

Hmm... I suppose I ought to do it again one of these days. I noticed an engine mount nut was completely loose. In fact, I've noticed quite a few things around the boat that seem to have come loose over the winter.

 

[Afrakes]

Hull Relaxation

Let the hull relax in the water for a couple of weeks then attempt the alignment. It can be a tedious job so have a lot of patience on hand as well as some libation to reward yourself upon completion. To do it yourself is rewarding and well worth the effort. Save the $600 for more important stuff. Prepare well. Make sure that the leveling nuts on the mounts are not rusted in place. Give them a good soaking of PB Blaster if you find that they are and work them so they can move with little effort. Also make sure you also line up an appointment with your chiropractor(sp) in advance.

 

[Alan Gomes]

Let the hull relax in the water for a couple of weeks then attempt the alignment. It can be a tedious job so have a lot of patience on hand as well as some libation to reward yourself upon completion. To do it yourself is rewarding and well worth the effort. Save the $600 for more important stuff. Prepare well. Make sure that the leveling nuts on the mounts are not rusted in place. Give them a good soaking of PB Blaster if you find that they are and work them so they can move with little effort. Also make sure you also line up an appointment with your chiropractor(sp) in advance.

Regarding the PB Blaster: Good stuff but I think you would want to keep it off the rubber parts of the motor mounts. Maybe spray some of the Blaster into a small cup and use a brush?

 

[Griff]

Thanks to All!
I have ordered the books. I like knowing how and performing work on the boat myself.
Regards,
Kevin

 

[Timsb]

I just did mine for the first time last weekend after changing the mounts. It wasn't that bad. Leave one bolt in the coupler loosely, then adjust the clearance side to side by moving the engine to make the gap equal on both sides. Once that's dialed in tighten the mounts to the stringers. Then adjust up/down - top/bottom of the coupler. That was the easy part. I got mine to withing .002 in no time. Of course I will need to do it again once the engine settles on the new mounts and the boat is dropped in the water but it is definitely not that intimidating anymore. Below is a link, it's only one link of dozens that I read. I read one of maine sails posts along the way and his description of the entire process was the most thorough. Good luck

read maine sails's post "here's how"
http://forums.sailboatowners.com/index.php?threads/shaft-alignment.109575/

http://www.saildonnybrook.com/2011/06/engine-mount-epilogue.html

 

[Doug177]

Could pounding into waves for 12 hours shift the engine alignment?

Hi...it's Doug, we just brought our "new" E35-3 with the M-25 diesel down Lake Michigan 2 weeks ago and are very happy with the boat's performance and the many wife friendly features. (compared to our older S2 7.9)

One thing I do notice after 2 days of pounding into a 3-4 ft chop is that in it's new home, the boat now pulls fairly hard to the left under motor, not under sail. Did not notice this before the trip and IT IS VERY NOTICEABLE. It does have more vibration than it did before the trip too. I dove under, and there are no fishing nets or obvious issues concerning the prop or rudder.

So my question is, could there be enough slop in the 30 year old motor mounts to cause a shift in alignment enough to create this strong pull to the left? This thought just struck me and I have not had a chance to check for broken mounts and such.

Doug

 

[Timsb]

I don't think the engine could be misaligned so much as to cause the boat to pull to one side. Vibration, yes. Could it be prop walk, a bent prop or prop strut?

 

[toddster]

That is just the normal effect of prop-wash playing on the rudder. Hardly noticeable at idle, pretty stiff at cruising speed, and a real bear at WOT. Yet another reason for a tiller pilot. (Prop wash? What prop wash? I haven't hand-steered while motor-cruising in months!). Although if you are running at speed, hoist the sails, then cut the motor and fall off to let the sails fill... Otto gets pretty darned confused for a while and has to "learn" the new rudder rules.

 

[Christian Williams]

I never met a boat mechanic, good or bad, who didn't tell me I should have something else checked.

Replace the missing bolt and see how things go. I call it "gathering information"....