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Todd Brosius
07-20-2008, 11:19 PM
When checking for leaks in my packing gland I noticed that my drive shaft is slightly touching the packing nut. There is NO vibration, NO scarring, and NO sounds that metal is rubbing against metal (brass nut). Is this an automotic indication of needing to check my alignment or should I wait until my packing begins to leak or needs replaced? What is best for the boat? '04 Prostar 197 170 hours

I have already printed a copy of shaft alignment procedure. Doesn't sound like it too difficult - Knock on wood.

Thanks in advance for the help.

Storm861triple
07-20-2008, 11:53 PM
My boat had the exact same problem, and it was so bad in fact that the shaft was "sawing" though the packing nut! I fought w/this problem for awhile, using the factory recommended procedure, and at first, not understanding why it wasn't working. I mean, MC SAID "this is how you do it". The problem is, the factory recommended procedure is missing a crucial step, and makes assumptions (that the boat was built/rigged properly).

A PROPER SHAFT ALIGNMENT STARTS WITH THE STRUT.
The first thing that you need to do, is unbolt the coupler at the transmission, separate the two flanges, remove the flange from the prop shaft, and then remove your packing entirely. In this state, the only thing holding/directing/supporting the prop shaft, is the strut.

Keeping in mind the "weight" of the shaft hanging in the strut, and the "slop" in the strut busings, where does the prop shaft "lie" in the prop log? It should be damn near centered in the prop log, but if your boat is like mine (and others) it may not be. If it is not centered NO AMOUNT OF ENGINE MOVEMENT ("alignment" per MC's direction), WILL SOLVE THE ISSUES. The issue is that your strut isn't properly mounted to the hull, OR it's bent.

If this is the case, you need to take what ever steps are necessary to get the prop shaft centered in the prop log. Verify that the strut is straight. Replace if not. Then you may have to shim or re-align the strut relative to the hull to get the prop going straight through the prop log. On MY boat, I had to grind the strut mounting bolt holes laterally, so that I could "steer" the strut left of right a little bit, to get my propshaft where I wanted it. This was w/a brand new MC sourced strut and new propshaft, BTW.

AFTER you have centered or verified the centering of the propshaft in the prop log, at that point, proceed w/the alignment, per MC's recommendations.

After the engine is properly aligned to the shaft/flange, THEN remove the flange from teh prop shaft again, and reinstall the packing and tighten to spec. The reason why you want to put the packing on last is b/c the packing and the way it's secured to the prop log is so stiff, that it can actually move your prop shaft some, one way or another. You would then be aligning your engine to that position which wouldn't be correct b/c the shaft would be preloaded to one side.

Clear as mud?

-Tom

Todd Brosius
07-21-2008, 12:24 AM
Wow - thanks for the info!!

Storm861triple
07-21-2008, 12:32 AM
No prob. Ask if you need any more help or anything. :)

Todd Brosius
07-21-2008, 01:45 PM
I should have asked then - Is this something I can wait to do for a couple months when boating is over. I'm guessing this has been this way for 4 summers now - not sure. To be honest I took the packing and alignment for granted. NOT anymore. Am I OK for a few more hours on my boat. I have some new packing coming in the mail so I'll be ready to do this. Can I start with just trying to align the shaft via Mastercraft procedures? Just wanting to make sure I'm not damaging something further. As I stated before, NO vibrations, scarring, noise or water leaking.

Thanks again.

Storm861triple
07-21-2008, 02:34 PM
You can definitely wait. A long time. I have a friend who owns a 1977 Ski Nautique, that I work on occasionally. His wife has run that thing aground so many times, hit rocks, etc. He is afraid of her, so doesn't say anything to her about it. The strut is bent, the propshaft is bent, the packing leaks, the drive train vibrates....just a terrible example of boat maintenance! My friend won't fix it because he knows his wife is just going to ram it into the earth again, so it's not worth the money. The boat has over 800 hours on it, and basically, functions fine. Proof (to me) that an out of whack drive train isn't detrimental.

You can start by trying MC's procedure, but if the strut is off what's the point? If your strut to hull alignment isn't right, and you align your engine to that, then your propshaft is still going to be bent or forced to bend anyway, in order to not hit the I.D. of the prop log.

If you want the quickest fix, don't worry about any part of the alignment for now, and just loosen the hose clamps that holds the packing assy to the prop log, and sort of "encourage" it to relocate to a better place, that is more centered around the prop shaft. Also, you'll probably need to remove and reinstall the actual packing material -the wax rope, so it's roughly centered, because right now it can't be. Remember, I said that the packing hose/mount is pretty stiff, so you can angle it/move it and get it to stay put roughly where you want it. That will eliminate your original issue, then you can get to checking your drive train alignment later.

Keep in mind that it's is possible that your drive train IS aligned fine, but the packing is just skewed to one side, causing the nut to hit the shaft. A VERY quick way to test your drive train alignment it to turn the prop by hand when the boat is on the trailer. If it turns very easy (one or two fingers) then it's probably pretty good. If you need two hands to turn it, then something is not right.

CantRepeat
07-21-2008, 04:21 PM
Thomas,

Thanks for post that info!

I recently bent a prop, prop shaft, and strut so I'll be using this very soon. The information about bolting the coupler to the trans with nothing else but the sturt to line up the strut and shaft is awesome! I don't think I would have gone that route and thus wasted about a grand in new parts not being installed right.

The sad part here is what you are saying makes total common sense and I never thought about it.

Thanks again!

Storm861triple
07-21-2008, 05:27 PM
Glad you appreciate my input! :)

The first time I posted this info I got berated, because what I was trying to convey, isn't covered in the factory manual. I think the school of thought was something like: "how dare you second guess Mastercraft", and "You must be a moron". Not in those words, but that was the gist of it. Apparently, that post was deleted because now I can't find it which is a bummer, because it had good info in it, and the OP of that thread found the exact problem I was describing, and fixed it.

Anyway, it's cool to explain it now, and "see" you understand what I'm saying. Again, I'm glad I could help and good luck w/the project when you tackle it. When it's done right, it's pretty rewarding, IMO.

-Tom

FrankSchwab
07-21-2008, 06:00 PM
I thought about this issue a lot when I did my alignment this winter...

The Factory approach solves one problem: it prevents excessive loads on the output shaft bearings in the transmission or V-drive. If there is more than the .003" gap at the coupler, then tightening the bolts is going to take up that gap, and can end up applying severe loads on the bearing. This can cause high-dollar warranty issues.

As you said, the Factory approach does not solve driveline bending issues. As long as there is less than .003" at the coupler, your stainless steel shaft could be making a 90 degree bend to the prop and it wouldn't strain the bearings, as long as rotating it (which would bend the shaft for each rotation) kept the clearance. Stainless steel isn't real susceptible to stress cracking, so bending back and forth half an inch isn't likely to destroy the propshaft for hundreds or thousands of hours.

When I did mine, I removed the packing (needed to replace it anyways), separated the rubber packing assembly hose from the hull, separated the coupling, then wiggled the shaft up and down left and right until I found a spot which I thought:
1. Centered the shaft in the cutlass bearing
2. Removed the 1/2" or so of bend in the shaft due to the transmission side being unsupported.
This, I felt, was the right answer - no propshaft flex while rotating, no side loads on the cutlass bearings. Fortunately, this position also happened to center the propshaft in the log on my boat, so I didn't have to worry about that.
Then, I moved the engine to match the new location of the propshaft coupler (about 1/2" to the side and 3/4" above the old location, IIRC). It took all of the adjustment range in two of the engine jacks to get me there. Some small adjustments to get the .003, and I'm good to go.

Runs real smooth now.

/frank

Todd Brosius
07-21-2008, 06:17 PM
Spoke with a Mastercraft mechanic today and after a LONG discussion of explaining my issue he said, "enjoy the boat." As stated above (which I did NOT know at the time) just because my drive shaft maybe slightly touching the brass packing nut does NOT mean that my drive shaft is out of alignment. I am a long ways from my dealer so a wasted trip with gas prices makes no sense and he said odds are there is nothing wrong with my alignment since I have no signs and symptoms of such. As i read above, I did think of "persuading" my rubber hose to center the packing nut on the shaft but I don't know as if I will even do that after talking to a Mastercraft mechanic. I did order a packing gland to be safe and I'll be ready to repack if I even ever have a leak, which I currently do not. Thanks again for all the help. Us central NE people are a LONG ways from civilization!!!!!!

Storm861triple
07-21-2008, 08:40 PM
Todd, don't forget, for nearly no time or effort, you can do the "pinky prop turn test". :)

If you can't turn it w/your pinky, something is binding, and you'll know.


As you said, the Factory approach does not solve driveline bending issues. As long as there is less than .003" at the coupler, your stainless steel shaft could be making a 90 degree bend to the prop and it wouldn't strain the bearings, as long as rotating it (which would bend the shaft for each rotation) kept the clearance. Stainless steel isn't real susceptible to stress cracking, so bending back and forth half an inch isn't likely to destroy the propshaft for hundreds or thousands of hours.
^This guy "Get's it" too. Cool. :)

MariStar-Man
02-07-2010, 12:27 PM
If this is the case, you need to take what ever steps are necessary to get the prop shaft centered in the prop log. Verify that the strut is straight. Replace if not. Then you may have to shim or re-align the strut relative to the hull to get the prop going straight through the prop log. On MY boat, I had to grind the strut mounting bolt holes laterally, so that I could "steer" the strut left of right a little bit, to get my propshaft where I wanted it. This was w/a brand new MC sourced strut and new propshaft, BTW.


-Tom


Great Write up Tom! I had a similar situation where after installing New Vesconite Bearings, My Drive Shaft was touching the Hole where the driveshaft enters the boat.

I used the Caveman Method to straighten the strut. I disconnected and slid the Driveshaft down just far enough to clear the hole and while still in the strut, i grabbed the top part of the shaft and pulled in the opposite direction.

After 3 short quick mild pulls, The strut was alligned, and the Shaft was centered in the hole perfectly as it hung being supported by the New Vesconite Shaft Bearing I had installed. I was amazed that this had worked. I thought to myself that if it didn't I was taking it to MC Dealer anyway to be fixed...

I then Mic'ed the shaft and fortunately, it was under the .004 around, and was actually better than when i started. Luckily, I pulled on the side of the shaft that needed the pullling...lol:D