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Old 12-26-2018, 08:49 AM   #21
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I have an old boat, my boat uses shims not nuts. I would imagine you will be chasing nut based alignment for the duration of the ownership of the boat. I have lots of shims. Big shims, small shims, paper thin shims and 1/4" shims. Like I said I have an older boat. When aligning I would love the ease of a nut to make it perfect but, how long will it last?
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Old 12-26-2018, 09:08 AM   #22
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I'm no fan of flex couplings, I've seen too many fail and I believe it encourages sloppy alignment.

In order to carry out an alignment, the flex coupling must be removed, none that I've seen have surfaces that are true enough to check alignment. Doing this requires that you be able to pull the couplings together with the flex coupling removed. If Spurs are installed, that may not be possible. As an aside, Spurs sells a precision shim that can be installed to gain the necessary clearance for Spurs installation. That same shim can be used to replace a flexible coupling.
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Old 12-26-2018, 09:43 AM   #23
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Just an fyi as to aligning a flex... Maybe not all are as easy as PYI's.



Quote:
Flexible Shaft Coupling Installation Instructions

  1. Roughly align engine and stern gear without flexible coupling i.e. only two rigid half couplings pushed together.
  2. Bolt the R&D Marine coupling between the two rigid couplings. Tightening details as below.
  3. Check alignment of the engine by placing feeler gauges between the Red Cone Headed Bolt and the rigid half coupling. Repeat for the Same bolt at 90 degrees intervals by rotating the shaft.
  4. If the gap is the same in all four positions, the engine is accurately aligned. Recommended minimum to maximum gap difference 0.010 inch/ 0.25 mm.
  5. Run installation to bring engine compartment to working temperature. Re-check torque settings.

https://www.pyiinc.com/flexible-shaft-couplings.html
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Old 12-26-2018, 12:29 PM   #24
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For clarification. Did they say the alignment is 0.008 or did they say it was out by 0.008?



When I do gen alignments we have a max total of 0.005 out. If it were 0.008 out. That would mean the actual alignment is 0.013
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Old 12-27-2018, 02:38 AM   #25
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Originally Posted by Steve DAntonio View Post
I'm no fan of flex couplings, I've seen too many fail and I believe it encourages sloppy alignment.

In order to carry out an alignment, the flex coupling must be removed, none that I've seen have surfaces that are true enough to check alignment. Doing this requires that you be able to pull the couplings together with the flex coupling removed. If Spurs are installed, that may not be possible. As an aside, Spurs sells a precision shim that can be installed to gain the necessary clearance for Spurs installation. That same shim can be used to replace a flexible coupling.
When you say that you have seen many failed couplings, is it your experience that they fail from ordinary use, ageing out so-to-speak? I ask because I just experienced a failure when attempting to back off a sand bar I found at a very low tide exiting an anchorage. I assumed I had backed into another part of the bank causing the coupling to break but I had hardly moved, felt no "motion stop", and my other shaft stayed coupled. Plus, my DeFever 44's props sit above the bottom level of the props and are thus somewhat protected so I am suspicious that the coupling failure (Globe Drivesaver) was coincidental. I am hoping it was coincidental cuz I, of course, am also concerned about prop damage.

Also, after being towed off the bar after a rise in tide, I motored 39 miles to a marina on one engine. It was a slower trip as set the RPM at 1,400 which gave me an average speed of 6 MPH. And, no, the parted shaft did not turn moving through the water and it was secured in place just in case. The boat ran quite smoothly.

I have a replacement on the way, two ordered to have a spare on board. Fortunately, on my boat the fix is easy. No more than a one-hour job.

Don't couplings have a service life as well? Also, would you recommend removing the couplings and installing a spacer machined to fit that space? I do have line cutters installed so there would be that issue.
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Old 12-27-2018, 04:15 AM   #26
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Quote:
Originally Posted by Steve DAntonio View Post
I'm no fan of flex couplings, I've seen too many fail and I believe it encourages sloppy alignment.

In order to carry out an alignment, the flex coupling must be removed, none that I've seen have surfaces that are true enough to check alignment. Doing this requires that you be able to pull the couplings together with the flex coupling removed. If Spurs are installed, that may not be possible. As an aside, Spurs sells a precision shim that can be installed to gain the necessary clearance for Spurs installation. That same shim can be used to replace a flexible coupling.
Thanks for the info about the Spurs Spacer. I have been looking for something like this so that I can do a proper alignment on my engines. I have the savers on my engines. I canít go without something since my shafts arenít long enough to remove the savers and slide the shafts forward. I am going to look into the Spurs Spacers.
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Old 12-28-2018, 01:14 PM   #27
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[QUOTE=catalinajack;726255]When you say that you have seen many failed couplings, is it your experience that they fail from ordinary use, ageing out so-to-speak?

SDA: Failed flexible couplings, these vary from an actual coupling that absorbs some misalignment, to insert flexible couplings that are placed between standard shaft and transmission couplings, to Drivesavers. As it happens the bulk of the failures I've seen have been for the Globe Drivesaver, although I've seen failures in all of the above-mentioned flexible couplings. My suspicion is it is misalignment induced, which creates heat and failures. The challenge is the alignment process for virtually all flexible couplings, it's not especially straightforward, and in the case of the Drivesaver, the it needs to be removed to check alignment, so I suspect many of these installations are misaligned.


I have a replacement on the way, two ordered to have a spare on board. Fortunately, on my boat the fix is easy. No more than a one-hour job.

SDA: I would make double sure alignment is correct. Globe Drivesavers are not intended to absorb other than very slight misalignment, their goal is to save the drive in the event of a prop strike (I have never seen one work this way).

Don't couplings have a service life as well?

SDA: Metallic shaft couplings? No, they are forever if properly installed. Flexible couplings are another story, if they are flexing with every revolution, logic dictates they will wear out at some point.

Also, would you recommend removing the couplings and installing a spacer machined to fit that space? I do have line cutters installed so there would be that issue.

SDA: I think you mean Drivesaver, not coupling. Again, I don't see a clear advantage to using the Drivesaver, so you could eliminate it and use the Spurs spacer.
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Old 12-31-2018, 07:31 PM   #28
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My engine has solid mounts, all adjustments are accomplished with the use of shims. It can be adjusted to a very fine degree, and that does not change when the motor is shifted or revved, as is the case with flexible mounts.
I believe this is where value of the drive saver device lies, it helps absorb the misalignment inherent and inevitable with flexible mount applications.
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Old 01-01-2019, 09:09 AM   #29
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Originally Posted by kapnd View Post
My engine has solid mounts, all adjustments are accomplished with the use of shims. It can be adjusted to a very fine degree, and that does not change when the motor is shifted or revved, as is the case with flexible mounts.
I believe this is where value of the drive saver device lies, it helps absorb the misalignment inherent and inevitable with flexible mount applications.
Again I'm dubious of virtually all of the claims for this product (except perhaps that it isolates the shaft from the engine electrically, that it does), however, absorbing misalignment isn't one of them https://www.gcsmarine.com/content/dr...rs/drivesavers

The website also claims they reduce vibration, these are about has hard as the heel of a dress shoe, there's simply no way they reduce vibration.

Even their alignment procedure is flawed.

"With boat in the water, loosen the hardware connecting propeller flange and reverse gear flange so that alignment of engine can be checked using a feeler gauge.

Leave bolts loosely connected during alignment process to support the propeller flange. Align engine installation to .005Ē maximum by adjusting engine mounts.

After successful alignment, completely disconnect propeller flange from reverse gear flange supporting dead weight of propeller flange."


You can't check alignment with coupling bolts installed, even loosely, you must be able to rotate the coupling faces relative to each other to ensure the gap remains constant.

I can find no mention on the product website of absorbing misalignment.

If you want to do that, you'd use a flexible coupling. The two are very different.
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Old 01-01-2019, 12:43 PM   #30
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I had a yard check my shaft coupling alignment recently. The yard reported that both engines were out by .008. The front of both engines need to lower. Problem is that the mount nut has no further adjustment. The engine needs to be jacked up and a thinner nut installed.
I had it checked due to a minor vib at higher RPMs. It turns out the props are out a little too.
Looking for thoughts on the alignment. The alignment was done in the water.

I'm curious...both engines out of alignment, by the same amount and in the same direction? Was the boat unusually heavily or lightly loaded? I noticed in every alignment procedure I've read, engine manufacturers specify that the boat must be evenly loaded with tanks at about middle capacity or above because hulls normally flex and deform based on loading.



Very interested in hearing expert opinions on this...
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Old 01-02-2019, 06:55 AM   #31
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Originally Posted by Riverguy View Post
I'm curious...both engines out of alignment, by the same amount and in the same direction? Was the boat unusually heavily or lightly loaded? I noticed in every alignment procedure I've read, engine manufacturers specify that the boat must be evenly loaded with tanks at about middle capacity or above because hulls normally flex and deform based on loading.



Very interested in hearing expert opinions on this...
Itís is odd that they were bothe the same. The boat was normal load with half full tanks.
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Old 01-05-2019, 01:13 PM   #32
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Also, would you recommend removing the couplings and installing a spacer machined to fit that space? I do have line cutters installed so there would be that issue.

SDA: I think you mean Drivesaver, not coupling. Again, I don't see a clear advantage to using the Drivesaver, so you could eliminate it and use the Spurs spacer.[/QUOTE]

Steve: I am going to take your advice and remove the Drivesaver using the Spurs spacer you mentioned. That spacer gets bolted between the transmission output flange and the propeller flange. How does one go about checking alignment? How would a mechanic secure the spacer either to the shaft or the transmission such that precise measurements could be made between the final mating surfaces? The spacer can't be bolted in place temporarily to one or the other lest the bolt heads prevent mating. What am I missing here?

I am having the props pulled and the cutless bearings replaced so eliminating the Drivesaver at the same time seems the way to go. I did read your articles the you posted a link to. In one of them you mentioned that you surveyed a boay the props of which you could not turn without Herculean effort. Mine are just the same and I am hoping that the source is swelled bearings and not misaligned bearing housings. The boat is a 1983 DeFever 44 so it's my guess that the bearings are swollen. Or, I suppose that both sides are severely out of alignment but that just doesn't make sense to me.

And thanks for all the free expert advice you provide to the folks on this forum. I am certain it valued by all.
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Old 01-06-2019, 12:41 PM   #33
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Steve: I am going to take your advice and remove the Drivesaver using the Spurs spacer you mentioned. That spacer gets bolted between the transmission output flange and the propeller flange. How does one go about checking alignment?

SDA: If the couplings can be brought together without the spacer, the process is how I described it in the article. Once the alignment is complete the spacer is inserted. If there is no room to do this the spacer will be retained in place by the pilot bushing and recess, with light forward pressure in the shaft coupling (you would do this in any event without the spacer), holding the spacer in place.

How would a mechanic secure the spacer either to the shaft or the transmission such that precise measurements could be made between the final mating surfaces? The spacer can't be bolted in place temporarily to one or the other lest the bolt heads prevent mating. What am I missing here?

SDA: It does not need to be secured per se, just held there sandwich-like by fwd pressure on the shaft coupling during alignment, and again you'd do this anyway.

I am having the props pulled and the cutless bearings replaced so eliminating the Drivesaver at the same time seems the way to go. I did read your articles the you posted a link to. In one of them you mentioned that you surveyed a boat the props of which you could not turn without Herculean effort. Mine are just the same and I am hoping that the source is swelled bearings and not misaligned bearing housings. The boat is a 1983 DeFever 44 so it's my guess that the bearings are swollen. Or, I suppose that both sides are severely out of alignment but that just doesn't make sense to me.

SDA: If the bearings are swollen that should be obvious when looking at them, there must be some clearance between the bearings and shaft, if there is none, and the bearing rubber seems compressed, it's likely a swelling issue. However, if the bearings are original this is unlikely, the problem usually manifests itself within the first year or two afloat. If they have been this tight all along I would be prepared for the possibility of shaft wear, the max allowable is 0.001".

The other possibility is this is a shaft to strut/bearing alignment issue, also discussed in the two part article. If the shaft is not centered in and parallel with the strut bearing that can lead to substantial shaft drag, especially if there is more than one shaft bearing (some Hatteras Yachts had four per shaft and it could be quite a chore to get them all lined up, there's a photo of one of those in the article, with the guy with one finger on the prop).

For prop installation this article may be helpful https://stevedmarineconsulting.com/p...-installation/

SDA: Keep us posted on what's found.

And thanks for all the free expert advice you provide to the folks on this forum. I am certain it valued by all.

SDA: Thank you and happy to know the material is useful.
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Old 01-06-2019, 03:17 PM   #34
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SDA: If the couplings can be brought together without the spacer, the process is how I described it in the article. Once the alignment is complete the spacer is inserted. If there is no room to do this the spacer will be retained in place by the pilot bushing and recess, with light forward pressure in the shaft coupling (you would do this in any event without the spacer), holding the spacer in place.

How would a mechanic secure the spacer either to the shaft or the transmission such that precise measurements could be made between the final mating surfaces? The spacer can't be bolted in place temporarily to one or the other lest the bolt heads prevent mating. What am I missing here?

SDA: It does not need to be secured per se, just held there sandwich-like by fwd pressure on the shaft coupling during alignment, and again you'd do this anyway.

Catalina Jack: Thanks for clearing up the methodology.

SDA: If the bearings are swollen that should be obvious when looking at them, there must be some clearance between the bearings and shaft, if there is none, and the bearing rubber seems compressed, it's likely a swelling issue. However, if the bearings are original this is unlikely, the problem usually manifests itself within the first year or two afloat. If they have been this tight all along I would be prepared for the possibility of shaft wear, the max allowable is 0.001".

The other possibility is this is a shaft to strut/bearing alignment issue, also discussed in the two part article. If the shaft is not centered in and parallel with the strut bearing that can lead to substantial shaft drag, especially if there is more than one shaft bearing (some Hatteras Yachts had four per shaft and it could be quite a chore to get them all lined up, there's a photo of one of those in the article, with the guy with one finger on the prop).

Catalina Jack: I do not know if the bearings are original. The boat is 35 years old so who knows. The boat is being hauled and blocked tomorrow. The first thing I will want to see, then, is whether the bearings are swollen. From what you say, this may be obvious upon visual inspection. I suppose the bearings could have been swollen for a very long time. The boat had 5,200 hours on the clock when we bought her five years ago.

Question: if a shaft is worn more than 1/1000, is it curtains for the shaft?

As for a strut/bearing misalignment I guess I am fortunate that a DeFever 44 has just two per shaft. For both sides to be misaligned one would think that the factory fouled up twice but, hey, if the same guy set both sides up (likely), then it's certainly possible that they were misaligned in the same way at the factory.

I guess, if I had to choose from two distasteful problems, I would hope for swollen bearings and worn shafts that need replacing rather than having to undertake realignment of the struts.

SDA: Keep us posted on what's found.

Catalina Jack: I will indeed keep the forum updated on the findings and fixes. I should know something definitively within a week.
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Old 01-07-2019, 10:27 AM   #35
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Question: if a shaft is worn more than 1/1000, is it curtains for the shaft?

It's not an issue of the shaft failing because of the wear. However, at some point it becomes an issue of shaft bearing to shaft clearance. If the shaft is worn 0.003", the new bearing's shaft clearance may already exceed the allowable limit, it will behave like a worn bearing. The result is you may have a rumble or vibration with new bearings. I've had clients say that's fine, they'll take their chances rather than pay for a new shaft. It will become your call.

For larger worn shafts they can be repaired using a process called cladding. Typically not economical on smaller shafts but if it there was a cladding shop nearby it may make sense. See the sidebar on page 46 of this article for more info https://stevedmarineconsulting.com/w...ent-159-02.pdf
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Old 01-22-2019, 04:34 PM   #36
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Originally Posted by catalinajack View Post
SDA: If the couplings can be brought together without the spacer, the process is how I described it in the article. Once the alignment is complete the spacer is inserted. If there is no room to do this the spacer will be retained in place by the pilot bushing and recess, with light forward pressure in the shaft coupling (you would do this in any event without the spacer), holding the spacer in place.

How would a mechanic secure the spacer either to the shaft or the transmission such that precise measurements could be made between the final mating surfaces? The spacer can't be bolted in place temporarily to one or the other lest the bolt heads prevent mating. What am I missing here?

SDA: It does not need to be secured per se, just held there sandwich-like by fwd pressure on the shaft coupling during alignment, and again you'd do this anyway.

Catalina Jack: Thanks for clearing up the methodology.

SDA: If the bearings are swollen that should be obvious when looking at them, there must be some clearance between the bearings and shaft, if there is none, and the bearing rubber seems compressed, it's likely a swelling issue. However, if the bearings are original this is unlikely, the problem usually manifests itself within the first year or two afloat. If they have been this tight all along I would be prepared for the possibility of shaft wear, the max allowable is 0.001".

The other possibility is this is a shaft to strut/bearing alignment issue, also discussed in the two part article. If the shaft is not centered in and parallel with the strut bearing that can lead to substantial shaft drag, especially if there is more than one shaft bearing (some Hatteras Yachts had four per shaft and it could be quite a chore to get them all lined up, there's a photo of one of those in the article, with the guy with one finger on the prop).

Catalina Jack: I do not know if the bearings are original. The boat is 35 years old so who knows. The boat is being hauled and blocked tomorrow. The first thing I will want to see, then, is whether the bearings are swollen. From what you say, this may be obvious upon visual inspection. I suppose the bearings could have been swollen for a very long time. The boat had 5,200 hours on the clock when we bought her five years ago.

Question: if a shaft is worn more than 1/1000, is it curtains for the shaft?

As for a strut/bearing misalignment I guess I am fortunate that a DeFever 44 has just two per shaft. For both sides to be misaligned one would think that the factory fouled up twice but, hey, if the same guy set both sides up (likely), then it's certainly possible that they were misaligned in the same way at the factory.

I guess, if I had to choose from two distasteful problems, I would hope for swollen bearings and worn shafts that need replacing rather than having to undertake realignment of the struts.

SDA: Keep us posted on what's found.

Catalina Jack: I will indeed keep the forum updated on the findings and fixes. I should know something definitively within a week.
Steve D'Antonio:

I promised to report back.

1. Six cutless bearings, all swollen.
2. Both shafts bowed (bent?) at transmission and at prop end. Very difficult to remove.

Repairs:

1. Shafts straightened.
2. Props tuned to Class 1 level.
3. New cutlass bearings.
4. Shaft log on one side replaced.
5. Engines aligned in the water. One side to .003, the other side to .004.
6. Drivesavers replaced with spacers from Spurs Co. as you suggested, picture attached.
7. New prop flanges.

Result:

1. Boat runs much more smoothly, quieter. No vibrations. Before repairs, significant vibration could be felt when standing on either side of aft cabin where the mid-strut is mounted.
2. The shafts were difficult to slide out. They went back in easily.
3. Before the repairs it was impossible to rotate the shafts even with pulling as hard as possible with a two-foot lever arm. Now they rotate easily.
4. Luckily, the struts did not require realignment.

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Old 01-23-2019, 04:53 AM   #37
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Jack:

That's great news, thanks for the update, and the coupling set up looks good (if the set screw has a hole in it for seizing wire it should be seized, otherwise use LocTite). The couplings and fasteners are all mild steel, so they should be corrosion inhibited.

You say a shaft log had to be replaced, why?
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