First signs of worn drive plates?

[Wanderer Vagabond]

Fairly simple question here, what are the first signs that you get that the drive plates are becoming worn? I know what they are on a car, once you start trying to go uphill you can hear the clutch start to slip, but so far I haven't found a way of taking the boat uphill.

The reason that I ask is that at the moment on some occasions when starting off from stationary I get vibration that feels like there is something on the prop. Take the power off and put it on again a few times and all seems well, but I'm not convinced that it is. (There isn't anything around the prop before anyone suggests that!)

[mrsmelly]

6 minutes ago, Wanderer Vagabond said:

Fairly simple question here, what are the first signs that you get that the drive plates are becoming worn? I know what they are on a car, once you start trying to go uphill you can hear the clutch start to slip, but so far I haven't found a way of taking the boat uphill.

The reason that I ask is that at the moment on some occasions when starting off from stationary I get vibration that feels like there is something on the prop. Take the power off and put it on again a few times and all seems well, but I'm not convinced that it is. (There isn't anything around the prop before anyone suggests that!)

There is often a " Chattering " sound as the springs in the plate become looser and start to break up, also a slight clunk on going forwrd to reversefor instance. I had a plate fail on my vetus setup and realised after its failure that it had been chattering for some time.

[Wanderer Vagabond]

6 minutes ago, mrsmelly said:

There is often a " Chattering " sound as the springs in the plate become looser and start to break up, also a slight clunk on going forwrd to reversefor instance. I had a plate fail on my vetus setup and realised after its failure that it had been chattering for some time.

Is that a sound coming from the engine? or could it appear to be coming from the prop? What I'm getting at the moment is a vibrating 'churning' similar to what you get when there is weed/plastic around the prop, there don't appear to be any untoward sounds coming from the engine.

[David Schweizer]

In my experience drive plates do not "wear out" in the same way that clutch plates do, instead they tend to start disintegrating, with the centre section eventually becoming detatched from the friction plate. As already suggested, this is usually indicated by a chattering sound, remarkably they will oftencarry on working for quite a while before failing. The plate on our engine literally fell apart when it was removed from the flywheel, but was still functioning albeit somewhat noisily.

[ditchcrawler]

9 minutes ago, David Schweizer said:

In my experience drive plates do not "wear out" in the same way that clutch plates do, instead they tend to start disintegrating, with the centre section eventually becoming detatched from the friction plate. As already suggested, this is usually indicated by a chattering sound, remarkably they will oftencarry on working for quite a while before failing. The plate on our engine literally fell apart when it was removed from the flywheel, but was still functioning albeit somewhat noisily.

As was ours, we had a gearbox failure and when it was removed it was only bits of spring connecting the spline to the plate, once it was removed it fell to bits.

[mrsmelly]

11 hours ago, Wanderer Vagabond said:

Fairly simple question here, what are the first signs that you get that the drive plates are becoming worn? I know what they are on a car, once you start trying to go uphill you can hear the clutch start to slip, but so far I haven't found a way of taking the boat uphill.

The reason that I ask is that at the moment on some occasions when starting off from stationary I get vibration that feels like there is something on the prop. Take the power off and put it on again a few times and all seems well, but I'm not convinced that it is. (There isn't anything around the prop before anyone suggests that!)

Have you got some sort of flexible drive? Python? Centaflex etc etc? that could be on the way out?

[Wanderer Vagabond]

1 minute ago, mrsmelly said:

Have you got some sort of flexible drive? Python? Centaflex etc etc? that could be on the way out?

No, just the prop shaft passing through a normal greaser gland (no leaks there either).

[mrsmelly]

1 minute ago, Wanderer Vagabond said:

No, just the prop shaft passing through a normal greaser gland (no leaks there either).

Check that the prop has not become loose on the shaft. I know you have checked its clear but they do come off from time to time, there are forum members on here its happened to and one of the twin props on one of the boats I skippered in Nottingham came off whilst going under Trent bridge even though recently mca checked. I wasnt driving at the time lucky for me.

[adam1uk]

11 hours ago, Wanderer Vagabond said:

 so far I haven't found a way of taking the boat uphill.

You haven't discovered locks yet?

[Wanderer Vagabond]

2 hours ago, mrsmelly said:

Check that the prop has not become loose on the shaft. I know you have checked its clear but they do come off from time to time, there are forum members on here its happened to and one of the twin props on one of the boats I skippered in Nottingham came off whilst going under Trent bridge even though recently mca checked. I wasnt driving at the time lucky for me.

I can even cover that base since the boat was out of the water being blacked on 3rd - 5th May and I had a good look at the prop and split pin at the time, all seemed pretty solid. The only other thing I can think of prop wise is that when I caught a log going through Gorsty tunnel a couple of months ago  it jammed and stalled the engine, there is a very small nick in the trailing edge of the prop (don't ask, I have no idea why it's on the trailing edge), but then in theory if that were the cause it should be vibrating all of the time rather than just occasionally when I start off.

Originally I thought that it might just be shallow water since that often causes this sort of vibration, but it does it in full locks (and coming up the Soar). Just a bit of a puzzle really, from what posters have said though it doesn't sound as though the drive plates are on their last legs (hopefully).

[mrsmelly]

12 minutes ago, Wanderer Vagabond said:

I can even cover that base since the boat was out of the water being blacked on 3rd - 5th May and I had a good look at the prop and split pin at the time, all seemed pretty solid. The only other thing I can think of prop wise is that when I caught a log going through Gorsty tunnel a couple of months ago  it jammed and stalled the engine, there is a very small nick in the trailing edge of the prop (don't ask, I have no idea why it's on the trailing edge), but then in theory if that were the cause it should be vibrating all of the time rather than just occasionally when I start off.

Originally I thought that it might just be shallow water since that often causes this sort of vibration, but it does it in full locks (and coming up the Soar). Just a bit of a puzzle really, from what posters have said though it doesn't sound as though the drive plates are on their last legs (hopefully).

I would guess the prop then. I whacked a refuse bin in a lock a couple of years ago and ended up replacing the prop. It was ok forwards but unbelievably bad when going astern

[Stilllearning]

To help identify if it is the drive plate, perhaps the old stethoscope trick could be employed. Some sort of solid steel pipe or big screwdriver with the shaft going through the handle, one end on the gearbox bell housing, other end on your ear. Put engine into gear and if the drive plate is close to knacked then you should be able to hear it clearly.

[ditchcrawler]

1 hour ago, Wanderer Vagabond said:

  I caught a log going through Gorsty tunnel a couple of months ago  it jammed and stalled the engine,  

In that case I would check the engine mounts

[Wanderer Vagabond]

2 hours ago, ditchcrawler said:

In that case I would check the engine mounts

I have checked the four engine mounts and there are no cracks on them, but how do you tell if they've been knocked out of alignment? The prop on the engine (when turned off and out of drive) turns easily by hand (as it always has done). There are no leaks from the stern gland, how else can you tell if it is out of alignment?

[Wanderer Vagabond]

3 hours ago, Stilllearning said:

To help identify if it is the drive plate, perhaps the old stethoscope trick could be employed. Some sort of solid steel pipe or big screwdriver with the shaft going through the handle, one end on the gearbox bell housing, other end on your ear. Put engine into gear and if the drive plate is close to knacked then you should be able to hear it clearly.

I will try that idea with a mooring pin on the gearbox, but not today as it's raining

[BWM]

13 hours ago, Wanderer Vagabond said:

I have checked the four engine mounts and there are no cracks on them, but how do you tell if they've been knocked out of alignment? The prop on the engine (when turned off and out of drive) turns easily by hand (as it always has done). There are no leaks from the stern gland, how else can you tell if it is out of alignment?

A failed engine mount isn't always visible to the eye, as the weight of the engine will hold it together. You may need to use a lever of some sort to lift each corner a little.

[Tony Brooks]

When the bolts holding the mounts to the bed become lose it can make all sorts of odd noises. Put a spanner on all of then nuts & bolts, especially the smaller ones in the engine beds.

[1agos]

I had an engine mount failure on the Thames. My first thought when I heard the noise it was making was that the gearbox had broken.

[Wanderer Vagabond]

4 hours ago, BWM said:

A failed engine mount isn't always visible to the eye, as the weight of the engine will hold it together. You may need to use a lever of some sort to lift each corner a little.

I used the engine as it's own lever by, whilst moored up, running the engine and putting it in gear and taking out of gear again, causing it to move on the mounts (as they are designed to do), no obvious sign of breakages on the mounts.

[Stilllearning]

Another trick to check engine mounts is to run the engine in neutral, and gently rest one foot on the rocker cover. If the engine immediately quietens,  then it is probably an engine mount that needs attention.

[Wanderer Vagabond]

Regarding the engine mounts, my brain has obviously been in neutral, immediately before having the boat blacked on 3rd - 5th May, I had the BSS examination carried out. Having looked at the book giving the full BSS checking procedures, they form part of the test so I can be reasonably sure that the mounts are OK (test by Trevor Whitling)