Alignment check
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If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
catalinajack
Guru
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.
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.
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/propeller-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.
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/propeller-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.
catalinajack
Guru
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.
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.
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/wp-content/uploads/2014/03/Shaft-Alignment-159-02.pdf
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/wp-content/uploads/2014/03/Shaft-Alignment-159-02.pdf
catalinajack
Guru
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.
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?
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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