I am a new CD25D owner and have a propeller shaft on my boat that moves in and out about 1/2 inch with a manual 'yank' to same. This was discovered when I hauled out this fall. I have 'yanked' on other shafts in the boatyard, including a CD30, and no other shafts perform this way. I noticed no problem when underway and the engine seemed to work well. However, I just don't think this is normal and would appreciate some advice from others out there who may have experienced the same thing and how they corrected it. Thanks ahead for any response.
mlitsche@hotmail.com
CD25D Propeller shaft problem
Moderator: Jim Walsh
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don sargeant
Re: CD25D Propeller shaft problem
Mimi,
Some transmissions have a cone that engages either forward or reverse depending on the lever position. the propellor shaft actually presses or pulls on the cone when in the water, but seems loose otherwise. The movement is about 1/2". The Westerbeke transmission does not work this way, the Volvo MD1 had such an arrangement. Perhaps the Yanmar does also. The only other reason I can think of for looseness in that direction would be a loose coupling, which you can easily see if you can stand on your head in the port seat locker.
Don Sargeant
~~COQUINA~~
CD25D #189
Sitting tight in Greenwich Cove
don@cliggott.com
Some transmissions have a cone that engages either forward or reverse depending on the lever position. the propellor shaft actually presses or pulls on the cone when in the water, but seems loose otherwise. The movement is about 1/2". The Westerbeke transmission does not work this way, the Volvo MD1 had such an arrangement. Perhaps the Yanmar does also. The only other reason I can think of for looseness in that direction would be a loose coupling, which you can easily see if you can stand on your head in the port seat locker.
Don Sargeant
~~COQUINA~~
CD25D #189
Sitting tight in Greenwich Cove
Mimi Litsche wrote: I am a new CD25D owner and have a propeller shaft on my boat that moves in and out about 1/2 inch with a manual 'yank' to same. This was discovered when I hauled out this fall. I have 'yanked' on other shafts in the boatyard, including a CD30, and no other shafts perform this way. I noticed no problem when underway and the engine seemed to work well. However, I just don't think this is normal and would appreciate some advice from others out there who may have experienced the same thing and how they corrected it. Thanks ahead for any response.
don@cliggott.com
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Larry DeMers
Re: CD25D Propeller shaft problem
It sounds to me like the set screws that hold the coupler flange to the prop shaft have come loose a bit. The prop shaft has two features that hold it from rotating and from slipping out backwards. The flange has a keyway cut into it, which matches another keyway (with key) cut into the shaft. This locks the shaft to the flange rotationally. The 2 or sometimes 4 setscrews hold the shaft in the flange, keeping it from slipping backwards.
This is easy to check, but you will need to get someone to move the shaft in and out from outside while you watch the action at the coupler from the inside..closeup, with wrench in hand. I would suggest that if you see the shaft moving in and out of the flange, but the flange doesn't seem to move nearly as much, then you need to tigthen the setscrews up a bit.
To do this, I would suggest taking care to back the set screws out maybe one or two turns only..but equally (ie: one or two exact turns). Push the shaft back into the coupling, and then tap the shaft end gently, with a small hammer padded with a wood block. The idea is to seat the shaft fully on the key in the keyway.
Hold the shaft and tighten the setscrews an equal amount until shaft contact is made. (Frequently, there are 'dimples' drilled in the shaft at the location that the setscrews are intended to be set into..if you have these, align them with the screws on the coupling, then tighten until contact is made.) Next rotate around the shaft, from setscrew to setscrew, tightening slightly, then moving on to the next screw. With 4 screws, do one side, then the other opposite side. Go to the other set of 2 and slightly tighten one then the other.
Finally, tighten each screw to it's final setting, then move to the opposite side and repeat until all are tight. Next, you will notice that these setscrews have holes drilled in them. Take S.S. rigging wire, and feed it through each hole. Cut and twist the two ends together until tight. Bend and stow this twisted end in parallel with the wire going through the holes to prevent it from grabbing stuff as it rotates (ouch!).
This will prevent any of the screws from unwinding again due to vibration.
If my concern for your prop shaft is correct, then;
Make certain that this is taken care of before splashing next spring, as the shaft could work loose. I don't know if it is free to leave the boat without removing your rudder, but on my CD30, it will leave if the rudder is turned hard a port. That leaves a rather large hole under about 3 ft. of water, which could be inconvenient.
Congrats on getting into a great sport with great people!!
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Sailing Lake Superior~~~
demers@sgi.com
This is easy to check, but you will need to get someone to move the shaft in and out from outside while you watch the action at the coupler from the inside..closeup, with wrench in hand. I would suggest that if you see the shaft moving in and out of the flange, but the flange doesn't seem to move nearly as much, then you need to tigthen the setscrews up a bit.
To do this, I would suggest taking care to back the set screws out maybe one or two turns only..but equally (ie: one or two exact turns). Push the shaft back into the coupling, and then tap the shaft end gently, with a small hammer padded with a wood block. The idea is to seat the shaft fully on the key in the keyway.
Hold the shaft and tighten the setscrews an equal amount until shaft contact is made. (Frequently, there are 'dimples' drilled in the shaft at the location that the setscrews are intended to be set into..if you have these, align them with the screws on the coupling, then tighten until contact is made.) Next rotate around the shaft, from setscrew to setscrew, tightening slightly, then moving on to the next screw. With 4 screws, do one side, then the other opposite side. Go to the other set of 2 and slightly tighten one then the other.
Finally, tighten each screw to it's final setting, then move to the opposite side and repeat until all are tight. Next, you will notice that these setscrews have holes drilled in them. Take S.S. rigging wire, and feed it through each hole. Cut and twist the two ends together until tight. Bend and stow this twisted end in parallel with the wire going through the holes to prevent it from grabbing stuff as it rotates (ouch!).
This will prevent any of the screws from unwinding again due to vibration.
If my concern for your prop shaft is correct, then;
Make certain that this is taken care of before splashing next spring, as the shaft could work loose. I don't know if it is free to leave the boat without removing your rudder, but on my CD30, it will leave if the rudder is turned hard a port. That leaves a rather large hole under about 3 ft. of water, which could be inconvenient.
Congrats on getting into a great sport with great people!!
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Sailing Lake Superior~~~
Mimi Litsche wrote: I am a new CD25D owner and have a propeller shaft on my boat that moves in and out about 1/2 inch with a manual 'yank' to same. This was discovered when I hauled out this fall. I have 'yanked' on other shafts in the boatyard, including a CD30, and no other shafts perform this way. I noticed no problem when underway and the engine seemed to work well. However, I just don't think this is normal and would appreciate some advice from others out there who may have experienced the same thing and how they corrected it. Thanks ahead for any response.
demers@sgi.com
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Mimi Litsche
Re: CD25D Propeller shaft problem
Don-- you have a CD25D as well--what kind of transmission does yours have? Do you not have the Yanmar 1G as well? Thanks to both of you for your responses.don sargeant wrote: Mimi,
Some transmissions have a cone that engages either forward or reverse depending on the lever position. the propellor shaft actually presses or pulls on the cone when in the water, but seems loose otherwise. The movement is about 1/2". The Westerbeke transmission does not work this way, the Volvo MD1 had such an arrangement. Perhaps the Yanmar does also. The only other reason I can think of for looseness in that direction would be a loose coupling, which you can easily see if you can stand on your head in the port seat locker.
Don Sargeant
~~COQUINA~~
CD25D #189
Sitting tight in Greenwich Cove
Mimi Litsche wrote: I am a new CD25D owner and have a propeller shaft on my boat that moves in and out about 1/2 inch with a manual 'yank' to same. This was discovered when I hauled out this fall. I have 'yanked' on other shafts in the boatyard, including a CD30, and no other shafts perform this way. I noticed no problem when underway and the engine seemed to work well. However, I just don't think this is normal and would appreciate some advice from others out there who may have experienced the same thing and how they corrected it. Thanks ahead for any response.
Mimi CD25D #54
mlitsche@hotmail.com