Shaft Alignment Question

JQ

Trey,

You missed what is being done with the gap. The gap is ONLY there when you are measuring for parallelism between the coupling faces. The engine is moved in any direction so the max difference side to side top to bottom is .003". This assures the prop shaft is aligned with the engine. After you get the max of .003"  the coupling halves are tightened. Take another look at one of the videos Ken linked.  Also as JQ mentioned, the prop shaft should be centered in the log. One other item on alignment is the shaft should also rotate freely in the cutlass bearing in the strut. 

Considering you moved the engine, I highly recommend a complete check for alignment.

Yes, you shouldn't be able to feel any shaft movement in the cutlass. 

On the removal of the coupling half off the prop shaft:

Jonny Quest wrote: Here is how I removed the coupler from the shaft In my direct drive.  First, I removed the safety collar from the driveshaft. Then I removed the bolts connecting the coupler to the transmission flange and separated the coupler from transmission flange. I was able to get 2” To 3” space between coupler and transmission flange.  Then I inserted a large, shallow socket between the coupler and transmission flange.  I then inserted some grade 8 bolts, washers and nuts through the coupler bolt holes and through the transmission flange.  Then by tightening down on the 4 bolts/nuts in sequence, the coupler on the prop shaft was “pressed” off the shaft.  Easy Peazy.  Hopefully my description makes sense. . JQ

Using find thread bolts and never seize will make it go easier. 

Multiple opportunities await you

You're gonna have the opportunity to learn how to take the coupling off your straight shaft with an interference fit as already mentioned.

Then you'll have the opportunity to learn how to remove the rudder so you can slide the shaft out

Then you should look at the rubber hose connecting the shaft log to the stuffing box because it's the ideal time to replace it if it looks old,ugly and cracked etc.

And then the opportunity to learn how to put that interference fit coupler back on the shaft which isn't any fun at all.

There are ways to make life easier by installing a double taper shaft but that comes with a price (new shaft and coupling).

Then reinstalling the rudder and deciding if you want to repack it at the same time.

I'd do lots of homework with searches here on CCF and elsewhere.

Some people might remove the rudder, leave the shaft alone and remove the strut to do the bearings, then reinstall the strut and do an alignment check. It avoids the shaft coupling removal and install issues  You don't get the opportunity to replace the hose between the stuffing box and the packing gland though   

Edit, based on a thought by Wetskier 2000 in a different thread, you could leave the rudder in place, unbolt the coupling halves and should have enough wiggle room to move the shaft enough to get the strut past the rudder.

 

You sure are 

With the amount of slop you have, it's a good thing to take care of it now though.

So my plan of action is to replace the shaft and coupler with the double taper system, replace the cutlass bearings, repack the stuffing box and add a safety collar to the shaft. While doing all this I'm going to very carefully and patiently check all the alignments to make sure it is straight and true.

Now to start spending money amassing parts!

Stainless will be easier to find. I've never had a problem with them being a dissimilar metal but, I'm in fresh  water. If you do get into salt or brackish It may be good to look for brass.

8122pbrainard wrote: Trey, Stainless will be easier to find. I've never had a problem with them being a dissimilar metal but, I'm in fresh  water. If you do get into salt or brackish It may be good to look for brass.

TG3 wrote: Thanks Pete. Only salt water here so I’ll go with Stainless. Maybe Lowe’s will have them and I can finish today.

So you say you're in salt water and you're gonna use stainless. 

Something's wrong here  

Maybe you meant to say "no salt water here"

Bronze and stainless are good together. 

So here is the next question, which is finally coming back around to my post title. I have the new strut bearings installed. I slid the new shaft into place to check if it was centered in the log. It is not. The shaft is off center to the starboard side and down. It is not touching the log, but definitely not in the center. I slid the shaft all the way up so that it touched the transmission coupler, and the over and down is apparent there too. I did some measuring and the shaft is approximately 17/64” off center at the log. That’s just under 1/4”. Watching some videos from Ski Dim and Ron Tanis, I don’t think it has to be perfectly centered, but surely closer than what I have now.....

One thing puzzles me. When I uncoupled the old shaft, I don’t remember it dropping down and over, which it should have done and more so, considering the worn bearings. 

I inspected the strut and it appears to be straight, with no visible bends or damage/scraps to indicate that it may have been hit. When you look at the depression in the hull where the strut is bolted through, the strut is shifted to starboard, not centered in the depression, corresponding with the offset position in the log. 

What is the next step I should take to get the shaft more centered in the log?

The centering of the shaft in the log doesn't have to be perfect but the 1/4" is more than I would feel comfortable with. Also, the 1/4" puts the shaft very close if not actually touching the log. You mention the strut doesn't look bent but it's tough to see by just a visual. At one time it may have been installed incorrectly too?  The solution is removing the strut, cleaning it and the hull up and then refastening it aligned. Port to starboard alignment of the strut can be done with the slop/clearance of the mounting holes/bolts. Minor up and down is down is done with washers between the strut base and the hull. In your case to raise the shaft at the log, you would put the washers at the aft holes. Dry fit the strut to cleck the alignment first.