Engine/shaft alignment

[sastanley]

Hi,
I've had some trouble finding a good comprehensive source for attempting to re-align my A-4 engine.

Background -
During the season last year, I noticed there was a slight wobble in the prop shaft under way, as the stuffing box would wobble a little bit. When the boat went in the water in May (2009), the cutless bearing was in good condition, although I believe it is original.

At any rate, over the winter, I believe I found the source of the wobbling...either loose motor mounts or mounts with lock nuts that have moved! :( Some have moved a LOT, a 1/2 inch or more, and some are seemingly still intact. I found a few loose lag screws holding the mounts to the rails, but I believe I have repaired those so they are at least not moving around anymore..the mounts were still intact, just the lags stripped out of the glass rails. The real mystery is which ones have moved & which ones haven't, so I figured I might as well attempt to re-align the thing.

I cannot for the life of me find a good tutorial with pictures or a diagram of where to stick feeler gauges or wedges or anything to align. I am hoping someone can help me figure out the procedure. :confused:

[hanleyclifford]

If you have mounting lags stripped out of the rails (sleepers), you are starting from square one. First fill the holes with epoxy, redrill and secure the lags in as near to original position as possible. The actual alignment procedure is simple but tedious. The goal is 4 point agreement around the coupling .003 of an inch or less. It is best to work with two feeler gauges opposite between shaft and engine couplings.

[sastanley]

HC,
Thanks for your help.. yes, stripped out lags..I think I have them all secure now (epoxy method).

Maybe I don't have a feeler gauge that is thin enough...I think my thinnest blade is .005.

On the other hand, the only gap I can see in the coupler arrangement is wider than ANY of my blades...1/8" or so by visual inspection...I must be staring at the wrong gap. :confused:

What I need is someone to take a picture with some gauges sticking out of their coupler and label everything like we did with the valve adjustment thread...it makes things easy for dummies like me..:rolleyes: - that procedure was an absolute cakewalk with the excellent tutorial (and pictures!) :D

[David Masury]

I will give you this suggestion.. when you go to re-align the engine to the shaft I would first go to your local hardware store or hobby shop. They sell these thin sheets of brass stock forp the hobbist..the thinner the better. Cut four strips about 3/8 wide and a couple inches long. When you slide the shaft coupler up to the engine, place the strips 90 degrees apart. Now carefully rotate the output shaft by hand. As you rotate the shaft, one of the strip will fall out indicating the direction you need to adjust the engine. Keep doing this until all the strips stay in.

I found this a much better way than using the feeler gauge and if I drop one, it is less of a concern that trying to find the feeler gauge under the engine.

David

[Triton106]

Shawn,

I just completed my A4 realignment project on my Pearson Triton and it is comprehensively documented on another forum (Plastic Classic Forum hosted by Tim Lackey). Here is the link.

http://www.plasticclassicforum.com/viewtopic.php?f=26&t=4710

Good luck,

Ray

[sastanley]

Hi Ray, thanks..I am a member at Plastic Classics...I'll check it out!

David, thanks for the tip..a thin sheet all the same thickness as a tool makes sense!

edit - Hi ray, I am almost halfway thru your thread over there...I have both Don Casey's & Nigel Calder's books...I'll reference them as well. (Duh!):rolleyes:

edit again - Wow...nice thread.. It is 10:30PM here, and I am glazing over about 60% thru....I must be missing something regarding the actual "coupled" parts. I tried with a simple wrench to loosen one of the three bolts without success....I guess I need to spray some PB Blaster, let it work, hold the shaft in between the studs still like I am trying to loosen a FWD car axle nut and see what's happening in there.

more edit - holy cow...there's two pages! :eek: BTW - I love everything I've read about Smiths pentrating epoxy..I have a quart of it in the living room ready for bulkhead strengthening! :cool:

[jhwelch]

I've had to do an alignment a number of times.

First I start out with the boat on land, so I can wedge a 2x4 between the propeller
and the aperture so I can unscrew the 3 bolts holding the coupling together.

Then I can turn the coupling and also feel around to see where there is a gap.

Since my engine is bolted to a fiberglass pan moving it is quite a chore. I use a
come-along to pull on the lifting eye and a tiller to pry it in a new direction.

Once it's lowered back I have to retighten the 4 engine bolts and then do the
feel around step again with the coupling.

Given how my engine is set up I don't have a better way, but somehow have
always found a sweet vibration-free spot after a few iterations.

-jonathan

p.s. I tighten my engine bolts every other oil change. Even using lock nuts
they slowly vibrate loose.