I've had an intermittent and troubling problem. I've never been able to demonstrate it to a mechanic (even after hours of motoring around), but it happened twice again today. Here's the problem...I'm motoring along and the engine or trans or drivetrain (I'm not sure where the source of the sound is) radically changes its sound. There is a loud vibration seeming to come from the aft and some screeching occasionally. If I lower the throttle, it goes away but will eventually return in minutes, days or weeks later. When motoring, recently there is a high pitched sound, as well...this occurs regularly now. Today, when I shifted from neutral to forward, it happened and I felt the vibration below my feet at the helm and the sound seemed to be in that area. The engine, however, does seem affected (but it's hard to tell since the sound is quite loud). When I returned to neutral and then shifted back to forward all went well for the rest of the day. I'm now wondering if rather than engine or trans problem (which 2 mechanics swear are in excellent shape....even as of yesterday), the problem is the cutlass bearing. For those of you who have had cutlass bearing problems, what were your sypmtoms...and are my symptoms familiar to you?. Thanks Chick Weiss Cara Carina; C36MkII E. Greenwich, RI
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T
Tom
rattling shaft
Dear Chick do you have a regular packing gland or dripless shaft seal. I have heard of your situation before and it could be a worn cutlass bearing but I have also heard a theory that dripless seals while they work great do not provide the same support for the shaft as regular packing glands. I don't know of ant way to check your cutlass bearing without hauling out unless your water is warm enough to dive down and see if there is movement of the shaft. I haven't had my prop shaft rattle like you describe for about a year but usually about once a season while cruising under power at 2200rpm I will get the rattle, which stops as soon as you throttle back. I had a friend who had a couple of mechanics look over things like you did without solving the mystery. Not much help but as they say "misery" likes company.
Dear Chick do you have a regular packing gland or dripless shaft seal. I have heard of your situation before and it could be a worn cutlass bearing but I have also heard a theory that dripless seals while they work great do not provide the same support for the shaft as regular packing glands. I don't know of ant way to check your cutlass bearing without hauling out unless your water is warm enough to dive down and see if there is movement of the shaft. I haven't had my prop shaft rattle like you describe for about a year but usually about once a season while cruising under power at 2200rpm I will get the rattle, which stops as soon as you throttle back. I had a friend who had a couple of mechanics look over things like you did without solving the mystery. Not much help but as they say "misery" likes company.
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Chick Weiss
I have a dripless seal
I have a dripless seal. Perhaps you are correct about this, Tom. This problem is inhibiting our fun and really limiting how far we take the boat. Given that, and that it's now approaching mid-summer, the investment in hauling is one I'll probably take. Thanks for your input and sharing in the misery. Chick Weiss Cara Carina, C36MkII E. Greenwich, RI
I have a dripless seal. Perhaps you are correct about this, Tom. This problem is inhibiting our fun and really limiting how far we take the boat. Given that, and that it's now approaching mid-summer, the investment in hauling is one I'll probably take. Thanks for your input and sharing in the misery. Chick Weiss Cara Carina, C36MkII E. Greenwich, RI
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david
cutlass bearing
When you're on the hard, grab the shaft and shake it. If you notice more than a couple of millimeters of movement, it should be replaced. I'm not sure if that's your problem though. I had some rattling in that area on my 1988 c-30 last year. I turned out to be the zincs comming lose on the shaft. HTH.
When you're on the hard, grab the shaft and shake it. If you notice more than a couple of millimeters of movement, it should be replaced. I'm not sure if that's your problem though. I had some rattling in that area on my 1988 c-30 last year. I turned out to be the zincs comming lose on the shaft. HTH.
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Tom
Chick, Why don't you have a diver go down
and do a quick check of the cutless bearing? It might not be 100% accurate, but if he says it looks bad, then I think the odds are high. Maybe the cutless bearing is loose and comes free and spins around once in a while. Also I have had weird experiences with shaft zincs, they will come slightly loose and spin around the shaft once in a while and cause symptoms a bit like yours
and do a quick check of the cutless bearing? It might not be 100% accurate, but if he says it looks bad, then I think the odds are high. Maybe the cutless bearing is loose and comes free and spins around once in a while. Also I have had weird experiences with shaft zincs, they will come slightly loose and spin around the shaft once in a while and cause symptoms a bit like yours
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Chick Weiss
Diver down yesterday
Thanks for all input. Yesterday, a diver did go down and the results are not really clear. He did say that there is some moderate movement of the shaft in the cutlass bearing, but he did not say that metal hit metal. Nonetheless, this probably indicates that the bearing ought to be replaced. Second, he posed a question that I'm wrestling with. He asked why is my prop about 4-5 inches aft of the strut....he said generally, it should be about 1.5 inches. He wonders if this is part of the problem and somehow it might be linked to the installation of a dripless shaft. I'm pursuing this with Catalina directly. For C36 MkII owners, can you tell me how far your prop is behind the strut. Chick Weiss
Thanks for all input. Yesterday, a diver did go down and the results are not really clear. He did say that there is some moderate movement of the shaft in the cutlass bearing, but he did not say that metal hit metal. Nonetheless, this probably indicates that the bearing ought to be replaced. Second, he posed a question that I'm wrestling with. He asked why is my prop about 4-5 inches aft of the strut....he said generally, it should be about 1.5 inches. He wonders if this is part of the problem and somehow it might be linked to the installation of a dripless shaft. I'm pursuing this with Catalina directly. For C36 MkII owners, can you tell me how far your prop is behind the strut. Chick Weiss
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Chick Weiss
Solution to Problem Found
I just called the former owner who immediately said that the "gremlin" had found me. He new exactly what I was talking about and said it began after he installed the dripless seal. He noticed the dripless shaft cavitating. At a boatshow he went to the company that makes the device and they gave him a one dollar solution that I'll now try: Purchase 900-1000 grit wet sandpaper; fold in half, put between the graphite and stainless steel plates of the seal and move it back and forth 5-10 times. The company rep said that any irregularity in the junction can lead to such vibration. The prior owner, like I, went through endless trials and errors before finding this (I hope) solution. Chick Weiss
I just called the former owner who immediately said that the "gremlin" had found me. He new exactly what I was talking about and said it began after he installed the dripless seal. He noticed the dripless shaft cavitating. At a boatshow he went to the company that makes the device and they gave him a one dollar solution that I'll now try: Purchase 900-1000 grit wet sandpaper; fold in half, put between the graphite and stainless steel plates of the seal and move it back and forth 5-10 times. The company rep said that any irregularity in the junction can lead to such vibration. The prior owner, like I, went through endless trials and errors before finding this (I hope) solution. Chick Weiss
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Tom
Prop about 4-5 inches aft of the strut !?!?!
No WAY !!! That is way too far !....are you sure he measured correctly. I have NEVER seen a Catalina 36 with a prop that far from shaft. The going recommended (ABYC and others) distance from the forward HUB end (not the blades) of the prop to the strut is 1.5 times the diameter of the shaft (1 inch in your case). I think he measured wrong
No WAY !!! That is way too far !....are you sure he measured correctly. I have NEVER seen a Catalina 36 with a prop that far from shaft. The going recommended (ABYC and others) distance from the forward HUB end (not the blades) of the prop to the strut is 1.5 times the diameter of the shaft (1 inch in your case). I think he measured wrong
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Chick Weiss
Prop - Strut Distance
Tom............I know that the diver did not measure wrong....he used his gloved hand to measure and the width of it fit exactly between the strut and prop hub. I also know he's correct since I used to put a zinc in that space and there was still room on both sides of the zinc. I've emailed Catalina to ask this question of them. I now know the 1.5 x diameter rule. The prior owner of the boat says he did not change the shaft.....perhaps this excess length is contributing to the cavitation of the dripless seal. Since I didn't install the dripless seal myself, I ask this question: Does such installation change the overall shaft length (from exiting transmission to end of prop)? I've read the installation instructions but have trouble visualizing it in the abstract. I'll update the list on what I find out. Thanks for your interest. Chick
Tom............I know that the diver did not measure wrong....he used his gloved hand to measure and the width of it fit exactly between the strut and prop hub. I also know he's correct since I used to put a zinc in that space and there was still room on both sides of the zinc. I've emailed Catalina to ask this question of them. I now know the 1.5 x diameter rule. The prior owner of the boat says he did not change the shaft.....perhaps this excess length is contributing to the cavitation of the dripless seal. Since I didn't install the dripless seal myself, I ask this question: Does such installation change the overall shaft length (from exiting transmission to end of prop)? I've read the installation instructions but have trouble visualizing it in the abstract. I'll update the list on what I find out. Thanks for your interest. Chick
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Tom
No, putting in a dripless shaft seal shouldn't
change the overall shaft length. It slides over the existing shaft, it doesn't add any length to it. I have a few questions. What kind of prop do you have? Do you have a Spurs Line cutter installed? What type shaft do you have(bronze or Stainless Steel) ? Are you sure someone didn't change the shaft since the boat was new? Does it have a plastic Shaft Isolator put in?
change the overall shaft length. It slides over the existing shaft, it doesn't add any length to it. I have a few questions. What kind of prop do you have? Do you have a Spurs Line cutter installed? What type shaft do you have(bronze or Stainless Steel) ? Are you sure someone didn't change the shaft since the boat was new? Does it have a plastic Shaft Isolator put in?
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Chick Weiss
More responses
I have a 3-blade fixed prop...factory installed. The prior owner was the first owner and he says that no shaft change was done....it is a stainless steel shaft. I don't have line/week cutters and I don't know about Shaft Isolator. I did call PYI this morning and they gave me the identical solution as the prior owner (sanding with 1000 grit paper). The tech there said that he believes that many Catalinas come off the line (particularly the 36s) with about 4 inches between strut and hub of prop. I'm still awaiting an answer from Catalina. I was told by Catalina yesterday that no new 36s are equipped with dripless seals and at the California plant, they don't have much feedback on how dripless seals perform on the 36. I also noticed on the PYI site, that many boat builders use their product as standard equipment, but not Catalina. More to follow. Thanks. Chick Weiss
I have a 3-blade fixed prop...factory installed. The prior owner was the first owner and he says that no shaft change was done....it is a stainless steel shaft. I don't have line/week cutters and I don't know about Shaft Isolator. I did call PYI this morning and they gave me the identical solution as the prior owner (sanding with 1000 grit paper). The tech there said that he believes that many Catalinas come off the line (particularly the 36s) with about 4 inches between strut and hub of prop. I'm still awaiting an answer from Catalina. I was told by Catalina yesterday that no new 36s are equipped with dripless seals and at the California plant, they don't have much feedback on how dripless seals perform on the 36. I also noticed on the PYI site, that many boat builders use their product as standard equipment, but not Catalina. More to follow. Thanks. Chick Weiss
T
Tom
Something doesn't sound right.
Catalina almost always supplies bronze shafts with thier factory C36's, unless of course the dealer did put it on originaly and charged the original owner. Maybe the Catalina dealer installed the dripless Shaft Seal as an Add-on when the orignal owner bought the boat and in the process changed out the shaft (not so uncommon, since you need to pull the shaft from the coupling anyway). It was probably an easy way for them to make some extra cash and when they did it they changed out the shaft for stainless steel and charged for that also (probably a good mark-up). But I suspect when they changed out the shaft they measured wrong and put in a shaft too long. They probably didn't care, because it wasn't thier boat! and it would still work....its just not a good thing at all. I know I would NOT be happy finding that out. First I would bring the shaft and coupling to a good prop/shaft shop and have it cut down to size and see if that fixes some of your problems. You could also have a slightly bent shaft. 3-4 inches overhang is way too much, even with a relatively light fixed prop and stainless steel shaft. Just as a point of reference I actually BENT a bronze shaft on my C36 from a hi-torque (forward reverse) shifting. I had only a 1.75 inches from the Prop Hub to the strut.....But it was an Autoprop (very heavy props) and a bronze shaft.
Catalina almost always supplies bronze shafts with thier factory C36's, unless of course the dealer did put it on originaly and charged the original owner. Maybe the Catalina dealer installed the dripless Shaft Seal as an Add-on when the orignal owner bought the boat and in the process changed out the shaft (not so uncommon, since you need to pull the shaft from the coupling anyway). It was probably an easy way for them to make some extra cash and when they did it they changed out the shaft for stainless steel and charged for that also (probably a good mark-up). But I suspect when they changed out the shaft they measured wrong and put in a shaft too long. They probably didn't care, because it wasn't thier boat! and it would still work....its just not a good thing at all. I know I would NOT be happy finding that out. First I would bring the shaft and coupling to a good prop/shaft shop and have it cut down to size and see if that fixes some of your problems. You could also have a slightly bent shaft. 3-4 inches overhang is way too much, even with a relatively light fixed prop and stainless steel shaft. Just as a point of reference I actually BENT a bronze shaft on my C36 from a hi-torque (forward reverse) shifting. I had only a 1.75 inches from the Prop Hub to the strut.....But it was an Autoprop (very heavy props) and a bronze shaft.
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Tom
PS....how does PYI tech know what comes out
of Catalina factory? The ones I know about and see never do. And I have seen a lot. (ps...something is very suspicious with the stainless steel shaft, I'm beginning to think you are not getting the whole truth with the history of your boat). Tom Senator Catalina 36 MKII Tech Editor
of Catalina factory? The ones I know about and see never do. And I have seen a lot. (ps...something is very suspicious with the stainless steel shaft, I'm beginning to think you are not getting the whole truth with the history of your boat). Tom Senator Catalina 36 MKII Tech Editor
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Chick Weiss
Thanks, Tom
Thanks for all of the detailed input. This problem has led to me learning a great deal of detail that I'd otherwise not known. I'm still curious about Catalina's response. Kent, at Catalina, thought 4 inches was not unusual...but then he said he wanted to check and see if that is indeed correct. Chick
Thanks for all of the detailed input. This problem has led to me learning a great deal of detail that I'd otherwise not known. I'm still curious about Catalina's response. Kent, at Catalina, thought 4 inches was not unusual...but then he said he wanted to check and see if that is indeed correct. Chick
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Tom
Remember to have him check AFTER the prop
is on. Because just measuring from the end of the shaft to the strut and "gestimating" the distance will not work, since the 3 blade fixed will eventually end up quite a distance up the tapered section of the shaft. (Also ask them what most Catalin 36 shaft material is leaving the factory) If it IS true, then get on the phone with Gerry Douglas (lead designer) and ask him what is his thoughts of having a prop hub 4 inches away from the strut on a 1 inch shaft. Especially when ABYC and other industry experts think 1.5 is the correct ratio and why do some boats lave the factory with less than 2 inches clearance.
is on. Because just measuring from the end of the shaft to the strut and "gestimating" the distance will not work, since the 3 blade fixed will eventually end up quite a distance up the tapered section of the shaft. (Also ask them what most Catalin 36 shaft material is leaving the factory) If it IS true, then get on the phone with Gerry Douglas (lead designer) and ask him what is his thoughts of having a prop hub 4 inches away from the strut on a 1 inch shaft. Especially when ABYC and other industry experts think 1.5 is the correct ratio and why do some boats lave the factory with less than 2 inches clearance.
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Chick Weiss
Catalina Measured Prop-Strut Distance
Just got an email from Catalina...three 36MKIIs were measured and the results showed that two had a distance from the strut to the prop hub of 2.5 inches. The third one was three inches but the writer was unsure if all connections were completed on this one. He suggests that my 4 inch distance should be examined and remedied, as you did. Many thanks again. ALso, regarding the dripless seal....so far there has been no recurrence of the vibration (after sanding was done). However, I can't feel confident yet since vibration sometimes occurred daily and other times not for a month. Chick Weiss
Just got an email from Catalina...three 36MKIIs were measured and the results showed that two had a distance from the strut to the prop hub of 2.5 inches. The third one was three inches but the writer was unsure if all connections were completed on this one. He suggests that my 4 inch distance should be examined and remedied, as you did. Many thanks again. ALso, regarding the dripless seal....so far there has been no recurrence of the vibration (after sanding was done). However, I can't feel confident yet since vibration sometimes occurred daily and other times not for a month. Chick Weiss
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