Spurs "ticking" noise?

[boomerang]

Last fall, while bring our boat South, we arrived at the bridge in Wrightsville beach early and ,as anyone knows who has ever been through that area, it is a terrible place to hang out while waiting for the timed opening, due to the strong currents and crowded development on both banks of a very narrow channel. Arriving early isn't usually more than an inconvenience but this time 'round, the winds were extremely high (and the tides extremely low)...so windy that the Figure 8 bridge wasn't opening (we mane it under with the tide boards showing 23' and the bridge tender climbed down to eye level with our mast and said we had a couple of inches to spare- good to know but too close for me) . So, while waiting at the Wrightsville bridge, I had to do a lot of forward/reverse shifting and lean heavily on the throttles to hold us in position. After we cleared the bridge, we noticed a ticking from the port engine drive train. I went into the engine room where I found transmission fluid under the clutch. The fluid level was a little low but I was fairly concerned to say the least and cut our destination short from Southport instead to Carolina beach (it was just as well because I really didn't want to be on the Cape Fear with the winds blowing like they were). After catching a mooring ball and having a whisky or 2 to relax, I found that a fitting on the hose had started weeping and it wasn't the catastrophic problem I was fearing. I made repairs and cleaned everything up. I started the engine and after putting it in gear, we could still hear a pronounced tick for every revolution of the shaft. It spun freely by hand as always so we decided to head out the next morning to see how things performed. We still had the disconcerting ticking as we went through Snows cut. It could clearly be heard in the aft stateroom and became more pronounced the closer you got to being over the wheel.
Long about the middle of the Cape Fear, Liz said the noise had stopped. Great I said, thinking we must've picked up something in Wrightsville and finally threw it off. Then it came back. Then it stopped. As it did for the rest of the trip.
I recently got around to hauling out at the marina just down from us to inspect the running gear. I explained to the guys at the yard what I was looking for and we all went straight to the port prop when the boat was up looking for the source and found...nothing. No foreign material or debris. The wheel was tight and true and spun freely. Both cutlass bearings on both sides were tight with no play. The rudder was tight. All of the Spurs hardware was secure. The only thing we noticed was that we could recreate the clicking sound by jiggling the spurs in their captive holder on the strut.
My question is, now that we're fairly sure the sound was (is) emanating from the Spur, why a click every revolution? I did have spare nylon bearings but it was getting late and we didn't see or feel any excessive wear or play in either set of Spurs so I didn't replace them. I probably will when we're up for the next haul out when we get home if the source of noise hasn't made itself obvious by then. Has anyone else experienced this type of behavior from a set of Spurs?

 

[O C Diver]

I usually assume a clicking noise is metal on metal. Did you replace all zincs while out of the water? Also, it seams odd that the noise went away and then came back. Finally, if it were a spur, I would expect the noise cycle to change with RPM or possibly go away at higher RPMs. For me, when tracking noises that may be engine related, one of my first tests is to see if it varies with a change of RPM.

While I use to limbo under the Wrightsville Beach Bridge, when approaching other draw bridges, I made a habit of slowing down to time the opening, arriving maybe a few minutes earlier.

Ted

 

[boomerang]

It definitely changed with the RPM's. With 3 to 1 clutches, it's easier to hear the increase/decrease with each revolution. The zincs were intact but not 100% new by any means. That appears to be where the sound is coming from since that's the point of captive contact on the Spurs but I'm wondering why the ticking. You'd think it would push up against the bracket on the side of rotation and stay there.
I normally to time our arrival based on bridge openings but like I said, the wind was ripping through the canal like a breezway and bridges were closing to navigation all around us so I wanted to be there in case the bridge tender had plans other than the normal opening schedule.

 

[O C Diver]

The steel charter boat I had in the 90s had two rudder zincs with one not tight enough. It started ticking only at certain speeds. Didn't find it even after hauling out at the end of the season. Only found it when removing the zincs when prepping for bottom paint the following spring.

Use to overnight in Southport until trying the mooring field in Carolina Beach. Don't know if you were aware of the pumpout dock, bath house, and the dinghy dock. Great protected location with restaurants and a well stocked Publix grocery store within a reasonable walk.

Ted

 

[Kapn]

I don't know why, but I've had the same thing on boats I've run before. I never had the chance to really look into the reason it was happening but the moving parts of the Spurs brand maybe get just loose enough to click as it rotates.

 

[bshanafelt]

If I recall properly, the Spurs has the rubber buttons to cushion the part from tapping against the stationary holder

Maybe these have fallen off?

 

[JackConnick]

I have them on my props and we had the same issue. There are silicone "Sound Dampening Plugs" that you can buy separately or as part of an overall maintenance kit. There are also plastic bearings that wear out.

The noise they make is annoying, but it's not hurting anything.

I had a diver take them off, ordered the right parts - as there are several sizes, even for the same size shaft. Then I rebuilt them and had him reinstall. Have had any further problems, but I moor in fresh water. The zincs on those have to be replaced at least once a year or so. I would just install an entire kit.

Sound Dampening Plugs Archives | SPURS MARINE

Spare Kits Archives | SPURS MARINE

 

[boomerang]

I have them on my props and we had the same issue. There are silicone "Sound Dampening Plugs" that you can buy separately or as part of an overall maintenance kit. There are also plastic bearings that wear out.

The noise they make is annoying, but it's not hurting anything.

I had a diver take them off, ordered the right parts - as there are several sizes, even for the same size shaft. Then I rebuilt them and had him reinstall. Have had any further problems, but I moor in fresh water. The zincs on those have to be replaced at least once a year or so. I would just install an entire kit.

Sound Dampening Plugs Archives | SPURS MARINE

Spare Kits Archives | SPURS MARINE

Thank you for the links. I don't recall seeing any silicone or rubber dampening pads on either of them ever but then again I'm not all that familiar with Spurs. Maybe it's a coincidence but I hauled out this past fall to put another set of wheels on and the guy who changed the wheels had to remove the spurs to get the prop puller over the shaft. I wasn't paying attention when he did it. Maybe something didn't go back correctly.
As long as the ticking isn't causing too much harm, I'll rebuild the things when we haul out after we get home.

 

[boomerang]

The steel charter boat I had in the 90s had two rudder zincs with one not tight enough. It started ticking only at certain speeds. Didn't find it even after hauling out at the end of the season. Only found it when removing the zincs when prepping for bottom paint the following spring.

Use to overnight in Southport until trying the mooring field in Carolina Beach. Don't know if you were aware of the pumpout dock, bath house, and the dinghy dock. Great protected location with restaurants and a well stocked Publix grocery store within a reasonable walk.

Ted

We've been to the Carolina beach mooring field twice now but have never taken the time to take the dink in and tour the area. It's definitely on our short list now that we're both semi-retired!

 

[Keysdisease]

The disc style line cutters have no moving parts and there is no alignment issues. This video by a boating magazine does an excellent comparison between several brands and types
Full disclosure: Before retiring I worked at a company that sold a disc style cutter

 

[jleonard]

I had spurs on my Mainship. Never heard any clicking but I do recall there were small diameter 1/8 inch) pads on one of the parts to dampen the movement and noise.
I can say for certain that they worked at least 3 times. All I could hear was a loud “ thunk” as the separated lobster buoy hit the hull.
I had a disk style (not shaft sharks) on the Albin but I think the hull shape prevented anything from fouling the prop/ shaft.

 

[Ken E.]

I had Spurs and heard the same sound. Spurs have zinc anodes which I thought were the culprit but they were tight and the clicking persisted. I never found the problem but replaced the Spurs with Shaft Sharks, a 1-piece, simpler design. No more clicking. Are are the Sharks as effective? I don't know but I hope so.

 

[Keysdisease]

Ken said: "replaced the Spurs with Shaft Sharks, a 1-piece, simpler design. No more clicking. Are are the Sharks as effective? I don't know but I hope so."

Watch the video I posted which compares the various types.

 

[boomerang]

The only 2 boats we've ever owned had Spurs line cutters were already installed when we bought the boat. I'm not sure if I would ever actually buy and install a set.
Ken, it makes me feel better to know that you couldn't nail down the source of the ticking sound either. Like I mentioned , we hauled out with the sole purpose of checking the Spurs due to the recent advent of clicking. Everything looked ok and no one could figure out what the cause was. I'll replace the bearings when we haul out later this season and hope that fixes it. I don't really care about the Spurs, I just don't want them doing damage to anything else down there.

 

[jleonard]

Dont forget that the thrust from the prop will load the running gear system axially and that slight movement probably can’t be duplicated while you’re on the hard inspecting clearances, etc.

 

[boomerang]

Dont forget that the thrust from the prop will load the running gear system axially and that slight movement probably can’t be duplicated while you’re on the hard inspecting clearances, etc.

That's a good point. I was having to use a lot of throttle just prior to the noise appearing. I can't say if it makes itself known while in reverse gear but it's definitely while in forward. I'd be scrutinizing the engine mounts after you've brought that scenario up but ours are solid mounts so not much chance of them collapsing. The shafts are tapered and nuts at both the wheel and on the coupling end so I don't think anything pulled loose there either. I will investigate the hardware in the engine room a little closer now.

 

[Mac2]

The disc style line cutters have no moving parts and there is no alignment issues. This video by a boating magazine does an excellent comparison between several brands and types
Full disclosure: Before retiring I worked at a company that sold a disc style cutter

Great video. I did have one spur break off. Didn’t know when it happened, but when I hauled out one spur had broken off and remnants of a blue tarp remained. Your video shows what a nightmare the tarps are.

 

[Keysdisease]

Dont forget that the thrust from the prop will load the running gear system axially and that slight movement probably can’t be duplicated while you’re on the hard inspecting clearances, etc.

Boomerang:
That's a good point. I was having to use a lot of throttle just prior to the noise appearing. I can't say if it makes itself known while in reverse gear but it's definitely while in forward. I'd be scrutinizing the engine mounts after you've brought that scenario up but ours are solid mounts so not much chance of them collapsing.

I doubt your engine is "solid mounted," and even with brand new mounts there will be a mm or 2 of axial movement under thrust which with Spurs can "complicate" alignment. This movement is just a typical result of having resilient engine mounts

 

[boomerang]

I doubt your engine is "solid mounted," and even with brand new mounts there will be a mm or 2 of axial movement under thrust which with Spurs can "complicate" alignment. This movement is just a typical result of having resilient engine mounts

Dang if I know, they look solid to me. No rubber or plastic anywhere that I can see. The Hatteras Mk1 literature says they're solid but the MkII (ours) seatrial article calls them "vibration isolators".

 

[Keysdisease]

Dang if I know, they look solid to me. No rubber or plastic anywhere that I can see. The Hatteras Mk1 literature says they're solid but the MkII (ours) seatrial article calls them "vibration isolators".

It would be very highly unusual for a Hatt (or any production pleasure vessel) to have solid mounted engines. Resilient mounts or "vibration isolators" must allow some movement of the engine in order to reduce engine vibration from transmitting into the vessel. That's why many shaft stuffing boxes are mounted on a piece of hose, to allow for shaft movement. These mounts allow engine movement P to S but limit fore to aft to allow for thrust taking in forward or reverse. "Limit," not stop, which is what Jay was describing, the shaft will move a couple of mm fore and aft under thrust, which is a result of the "vibration isolators" and can cause alignment challenges for Spurs installations.

 

[Daveo]

Just a caution concerning Spurs. I had my shaft grooved beyond repair by a loosened spur cutter spinning freely on the shaft. I’m not the only person to have suffered this fate. This could happen with a simple disc cutter as well, I suppose, or even a loosened shaft zinc? Hopefully a zinc would be soft enough not to eat the shaft. Only way to protect is frequent inspection. Makes me jealous of the Amels that have a viewing port allowing you to see the running gear.