aligning engine

[John G.]

Last year I changed the cutless bearing on my 25D but did not align the motor. I was told with such a small motor it wasn't really that critical. This year I intend to do the aligning but would really like to do it on shore (in my backyard) mainly because the boat is on a mooring an I would like to spare myself the countless dingy rides I know I will need to take. My questions are, (a) is this a bad mistake by not doing it on the water, and (b) any suggestions?

Thank You
John G.

[Parfait's Provider]

John G.,

I think you are right to want to check that alignment; transmissions are expensive and replacing them even more so. While they might not be as susceptible to damage from misalignment, the costs far outweigh the benefits of procrastinating.

I am not sure why it should take more than one dinghy ride unless, like me, you never get the right collection of tools to the job at the outset. Even then it shouldn't take many since you can determine what tools you will need while the snow melts and put them on board before you launch. You could also be certain that none of the nuts and bolts are frozen, making the floating portion of the job much simpler.

Unless you store your boat in a backyard pool, I suggest you wait until the boat has had at least a few days in the water before checking the alignment.

[Dalton]

I have always been told to wait 'til she's been in the water for a few days. Most boats change shape slightly when braced up. I replaced the engine in my previous boat, an Alberg 35, and did an initial alignment, of coarse, while braced up but did it again after a few days in the water. There was a little adjustment to be made.
So if you do it on the hard you should check it again once floating.
Perhaps the CD is so stiff that this is not a factor. However the people who told me not to do it 'til in the water were the folks at Robinhood.

GD

[Tony Jeske]

Don 't you just hate that? Some mechanic is too lazy to do the job properly, so he weasels out of the unpleasant part of the job by fabricating some story like the "small engines don't need alignment" misinformation. Gee, maybe small engines don't need their oil changed either! Aw what the heck, eliminate the cooling water, too!

If one thinks about it, a single cylinder diesel like yours, is liable to vibrate more than a multicylinder engine, and so is more likely to need careful alignment.
Regards,
Tony Jeske
CD-28 #365
NO REGRETS (Which placed 1st on our YC's St. Pat's Day Race last Sunday!)

[Bill Goldsmith]

If alot of engine/drive train work has been done recently, I would do the first fine alignment on the hard and then tweak it in the water. However, if a reliable alignment was done in the past couple of years, and no big work has been done, I'd just launch and do the fine adjustment in the water.

Last year I aligned Loonsong's W21a after totally removing it for new mounts, a new exhaust manifold, installation of a PSS Shaftseal and a new cutless bearing.

Your lazy mechanic only told you half the story (or perhaps the entire story as he understood it) My research indicates that, yes, all engines should be aligned properly, but that drive trains with relatively short shafts and relatively narrow shafts (read: just about all CDs) are more tolerant of some out-of-alignment than drive trains with long and relatively large diameter shafts.

However just because short shafts and narrow shafts may be more tolerant of some out-of-alignment does not justify the failure to perform the alignment in the first place.

So it is indeed important to get a good alignment, even on a small engine, and it should be checked and final-adjusted in the water. Since you presumably had the shaft out for the cutless replacement that's a great time to check the coarse alignment as well as the fine alignment.

Coarse alignment involves making sure that the shaft is centered in the shaft log and making sure that the coupler flanges line up and mate together. When doing a cutless bearing, the shaft has to be removed, and this is a great time to make sure the coarse alignment is satisfactory. I made a jig out of wood that holds the shaft exactly in the center of the shaft log, so that when the shaftseal (or stuffing box) is installed, and you can't see the inner end of the shaft log, you can still be confident that the shaft is in the center because of the jig. So far, all of this can and should be done on the hard.

Once the shaft is in the right spot, the engine can be coarse-aligned to the shaft coupler, i.e mating the two flanges. On my Westerbeke, the athwartships alignment is done by loosening the engine mount bolts and sliding the engine side-to-side, a very rough way of getting things aligned. That can be done on the hard as well.

Once the flanges are mated, the fine alignment is done, using the height adjustment bolts on the engine mounts to eliminate as much run-out as possible from the flange mating faces.

My long-winded answer can be boiled down: you can and should do the coarse alignment on the hard. Do a fine alignment on the hard as well but only if major recent work has been done or you are unsure as to the status of the alignment. Repeat the fine alignment after the boat has been in the water for about a week. Once you are confident in the alignment, next year just check it after launching. This all will minimize the amount of grunt mechanical work being done at the mooring.

Bill

[dwdisbennett]

I check the alignment on every boat I commision. The primary prerequisite is that the boat is in the water, rig up and tuned, and has been that way for 3 days. The shape of a boat will change sitting out of the water and a tuned rig will flex it even more. These are hard fast rules for me. After that you should only need 3 or 4 wrenches and a set of feeler gauges.

Most engine specs call for less than .003. Be aware that it is not unusual to have to lift the coupler a little to get it to mate with the engine. It's weight can flex the shaft some. Get the bottom of the coupler set by adjusting the rear mounts then set the top by adjusting the front mounts. If the sides are off you will have to kick the engine around on it's bed by sliding the mounts to one side or the other.

Good Luck

Dave

[Daniel VanWinkle]

John,

Could you provide info on how you did your cuttless bearing? I may be facing that problem soon. Where did you find the set screws that I've heard are inbedded in the exterior glass and hold the bearing in place? Any tricks to know? Thanks, dvw

[John G.]

Thank you for your input, I would just like to mention there was no mechanic involved just boatyard babble. All work is done by this lazy mechanic.
Thanks again
John G.
. boat: CD25D "Frangipani"
moored in Pawtuxet Cove R.I.

[Jim Lewis]

I have had my boat well over 20 years and was told when I got it by the surveyor to let the yard replace the cutlass bearing when wear required it. I have had a good yard replace it once about 12 years ago and then just replaced again last year by another yard.
I guess my shaft must be in alignment???????? How often does
everyone replace that bearing???????? I know I sure don t want
to have to chisel fiberglass if I don t have to......good luck Jim

[Mark Yashinsky]

First, search the archives. This has been discussed many times, along w/ issues and possible solutions that may come up.
Second in a nutshell, the cutlass bearing is a metal tube w/ a slotted hard rubber inner tube that the shaft runs on (the bearing). This unit fits into a tube glassed into the boat. This outer tube is part of the boat and not movable and the cutlass bearing unit should be a snug fit into it. Nothing to align here. There should be one or two set screws, possibly safety wired, near the outside end of the shaft (near the prop, buried in some epoxy. Use a dremal tool to careful grind away the epoxy to reveal the screws and remove them. W/ the shaft removed (see the archives), pull the cutlass bearing out (also see the archives!). Reverse this to reinstall.

To check the bearing, basically see how much side to side and up and down play there is, by taking the prop and move it around.