Drive Plates, how long do they last?

[Wanderer Vagabond]

Yes I do realise that it is a question that probably falls into the 'how long is a piece of string' category but I was browsing the website of one of the posters here (RWLP) where he has in interesting piece of just how wrecked these can be and still work.

 

It seems that, unlike the clutch plate in a car, there is not always a sign of impending failure. The car clutch will start to slip telling you that it is time to get the wallet out, but with a marinised engine drive plate, how do you tell?  Is this something that should be replaced on a 'preventative maintenance' schedule? and if so at what point should it be replaced? Since it involves quite a bit of work to get out, I'd hate to go to all that trouble only to find that the plate was absolutely fine. The alternative is just to carry on to destruction and then get it repaired when it fails, but, such is the way with life, it would undoubtedly fail at the most inconvenient moment and a long way from anyone who could help fix it, probably on a river somewhere.

 

At the moment I've travelled getting on for 5000 miles on the drive plate that was on the boat when I bought it. The engine hours at purchase were 1193 and are now 6820 so I've put on something like 5,600 hours of engine time. I can only assume that the drive plate is still the one that was fitted when the boat was built but I don't know what mileage the previous owners had done, and it is going to be the mileage (how many times it's been put into drive) that will be the defining factor.

 

So the question is, do I wait for it to fail? or go for preventative maintenance?

[canalpubs]

If your drive plate 'fails' is it one that will cease to work and you will have to be 'rescued' or a fail safe such as a Centaflex?

 

Suspect the engine was fitted with a standard Driveplate so ask the manufacturer of or Midland Chandlers or R&D and ask if they fail eventually 

[BruceinSanity]

A common scenario is one of the posts that goes through the slots in the driven part comes adrift and starts clattering around like mad, so a suddenly noisy drive is your cue to replace. The other thing that happens is the rubber bump stops at the end of the slots wear through making for a louder clunk when you engage drive. This happens with the ones at the forward ends first, naturally, so check for a difference in clunk between forward and reverse.

[Tony Brooks]

As Bruce above BUT those things start to happen gradually so you may not realise how much of a thump it makes when going into gear or how much it clatters until you hear another similar engine.

 

Not all engines have drive plates, a have a gearbox input shaft bolted to the flywheel while at least one other make has a     rubber and steel spider estrangement that will not fail ovre 10s of years. All the big common names made in the last 30 or so yours do though.

[Guest]

Well I am not an expert, but have had first hand experience!

First I don't understand the F/R thump comments. The engine drive plate is between engine and gearbox, so the thrust is in the same direction for forward and reverse. If you (or they) are talking about coupling between gear box and prop shaft then Ok.

Second, as I understand it, the engine drive plate is there to smooth out the engine rotation before the gearbox. My gearbox recently started to slip. On taking all apart it transpired that drive plate rubbers had collapsed possibly leading to premature failure of gearbox. There was no obvious evidence of this. I might add that I am somewhat paranoid about odd noises being something of a sound engineer. :-)

Having stripped down gearbox and plate myself I would be in the 'wait till it goes wrong' class. Cost more, but avoided grafting for as long as possible!!!

Hope this helps

John

[BruceinSanity]

26 minutes ago, Floating Male said:

First I don't understand the F/R thump comments. The engine drive plate is between engine and gearbox, so the thrust is in the same direction for forward and reverse.

You’re quite right of course. Not thinking clearly due to lack of tea first thing! The bump stops at the other end of the slots absorb the thump when you come reduce engine revs and inertia in the transmission spins the plate on.

[Guest]

Phew!

Of course I had had two coffees, which trumps one tea any time. :-)

 

Could add that in my case the rubber had disintegrated and jammed the whole thing, so simply no movement.

John

 

[Tony Brooks]

4 hours ago, Floating Male said:

Well I am not an expert, but have had first hand experience!

First I don't understand the F/R thump comments. The engine drive plate is between engine and gearbox, so the thrust is in the same direction for forward and reverse. If you (or they) are talking about coupling between gear box and prop shaft then Ok.

Second, as I understand it, the engine drive plate is there to smooth out the engine rotation before the gearbox. My gearbox recently started to slip. On taking all apart it transpired that drive plate rubbers had collapsed possibly leading to premature failure of gearbox. There was no obvious evidence of this. I might add that I am somewhat paranoid about odd noises being something of a sound engineer. ?

Having stripped down gearbox and plate myself I would be in the 'wait till it goes wrong' class. Cost more, but avoided grafting for as long as possible!!!

Hope this helps

John

But when in neutral there is far less load on the drive plate so it can move to a more central position within the wear movement so when yo put it in gear and the prop tries to stop the gearbox you get a noise of some sort  as the slack is taken out of the wear. What that nose will be depends if the drive is being transmitted metal  to metal, metal to rubber, metal to plastic, plastic to plastic or rubber to rubber. In fact the torsional oscillations from the engine are likely to actively help the drive to take up a central position within the wear.

[pearley]

Our Beta 43 started to rattle slightly at 6500 hours but would seem to disappear when the engine was hot. Eventually had a Beta engineer diagnose it as a failing drive plate. As you can see the 4 metal pegs have been rubbing and started to wear away and rubber bits have started to twist. 

 

So this year new prop, shaft and cutlass bearing and new drive plate. Engine has sounded so quiet for years. 

[mrsmelly]

This depends to me on risk and location of your cruising. I came down the Aire from Leeds on Christmas Eve not many ago with a blooming good flow on. My bro in law had arranged kindly to be at Castleford lock for me and as I approached he opened the gates and I turned in at a fair lick. If you don't know it well it's a big lock for proper commercial stuff so I didn't need to slow down. I cleared the gates into the cut off the river and engaged reverse and quite simply nowt happened. Moored up on the pontoon in the cut. Venus engine I hadn't owned very long less than 2k hours and drive plate simply jacked in the little springy things fell out and simply nowt happened, no drive. rcr attended and replaced as they do. There had been no clunking, no chatter or squeeling etc it simply jacked. At that location had the lock gates no been open my next stop was Castleford weir. So if you do river work they are easy enough to change and are not a lot of money for an R and D or somett for some piece of mind?

[Guest]

Hmmm

Well another variant...

My drive plate (which is a Centa CF) has no pegs like the one Pete has shown above. The Centa plate is just two concentric rings with rubbers in between. If the rubbers disapeared then there would be no noise (or drive!)

My engine had one similar to the above but when the gearbox played up about 10 years ago TW Marine recomended changing drive plate for the Centa. As I always do as I am told (And had an income then) it got changed!!!

 

Hope this doesn't start a drive plate comparison war.

 

John

[Wanderer Vagabond]

6 hours ago, Floating Male said:

Well I am not an expert, but have had first hand experience!

First I don't understand the F/R thump comments. The engine drive plate is between engine and gearbox, so the thrust is in the same direction for forward and reverse. If you (or they) are talking about coupling between gear box and prop shaft then Ok.

Second, as I understand it, the engine drive plate is there to smooth out the engine rotation before the gearbox. My gearbox recently started to slip. On taking all apart it transpired that drive plate rubbers had collapsed possibly leading to premature failure of gearbox. There was no obvious evidence of this. I might add that I am somewhat paranoid about odd noises being something of a sound engineer. ?

Having stripped down gearbox and plate myself I would be in the 'wait till it goes wrong' class. Cost more, but avoided grafting for as long as possible!!!

Hope this helps

John

I'm thinking that I might be joining that class as well. My understanding of the system (perhaps a bit limited) is that should the drive plate fail, I can still run the engine (thereby keeping batteries topped up, hot water etc) but just can't use it to propel the boat anywhere. I can work around that on the canal, it is on a river it may be problematic.

1 hour ago, mrsmelly said:

This depends to me on risk and location of your cruising. I came down the Aire from Leeds on Christmas Eve not many ago with a blooming good flow on. My bro in law had arranged kindly to be at Castleford lock for me and as I approached he opened the gates and I turned in at a fair lick. If you don't know it well it's a big lock for proper commercial stuff so I didn't need to slow down. I cleared the gates into the cut off the river and engaged reverse and quite simply nowt happened. Moored up on the pontoon in the cut. Venus engine I hadn't owned very long less than 2k hours and drive plate simply jacked in the little springy things fell out and simply nowt happened, no drive. rcr attended and replaced as they do. There had been no clunking, no chatter or squeeling etc it simply jacked. At that location had the lock gates no been open my next stop was Castleford weir. So if you do river work they are easy enough to change and are not a lot of money for an R and D or somett for some piece of mind?

It's funny because I first started considering what would happen if the drive plate were to fail whilst travelling from Naburn to Selby on the Ouse, through a load of debris on the river. The nearest I've had to a failure in the past was going through Gosty Tunnel when the local oiks had thrown a load of sawn-up logs into the canal and one wedged between my prop and the rudder cup, stalling the engine instantly. The drive plate seems to have survived that one but I was considering how I was going to turn into Selby lock on an ebbing tide if I had no power, had any of the debris on the Ouse done the same as the debris in Gosty tunnel had done.

[mrsmelly]

1 hour ago, Wanderer Vagabond said:

I'm thinking that I might be joining that class as well. My understanding of the system (perhaps a bit limited) is that should the drive plate fail, I can still run the engine (thereby keeping batteries topped up, hot water etc) but just can't use it to propel the boat anywhere. I can work around that on the canal, it is on a river it may be problematic.

It's funny because I first started considering what would happen if the drive plate were to fail whilst travelling from Naburn to Selby on the Ouse, through a load of debris on the river. The nearest I've had to a failure in the past was going through Gosty Tunnel when the local oiks had thrown a load of sawn-up logs into the canal and one wedged between my prop and the rudder cup, stalling the engine instantly. The drive plate seems to have survived that one but I was considering how I was going to turn into Selby lock on an ebbing tide if I had no power, had any of the debris on the Ouse done the same as the debris in Gosty tunnel had done.

Just to rub salt in the wound. When mine jacked in I tried to start engine a while after I had stopped it and it wouldn't spin, one of the springy things had jammed part of the ring gear. I suppose it depends on what kind of plate you have fitted. If I were even a little concerned I would change it if you are still doing the Ouse etc as even though we cant cover ourselves however good at maintainance we are for every eventuality losing drive on such locations would be an arse clenching situation!

[Tony Brooks]

To further rub salt into the wound if you had proper marine engines designed for the job drive plates would be very unlikely to come into it, far too unreliable for sea work.

[mrsmelly]

3 minutes ago, Tony Brooks said:

To further rub salt into the wound if you had proper marine engines designed for the job drive plates would be very unlikely to come into it, far too unreliable for sea work.

Please sir, please sir.... I did have a proper Bukh dv36 in one of my boats in the past ? Does that count? I know you still have one ?

[Bloomsberry]

There is a rattling noise from the gearbox/driveplate area on my boat, I've had the noise for 2 years now.

 

Gearbox is a borg warner 71C and acts as the front engine mounts so taking it apart in situ is not an option, I think the engine will need removing.

 

I have parts replacement cover with RCR but they will only attend on a complete failure so have the choice of either sorting it out myself or waiting until  failure and contacting RCR.

[Wanderer Vagabond]

2 hours ago, mrsmelly said:

Just to rub salt in the wound. When mine jacked in I tried to start engine a while after I had stopped it and it wouldn't spin, one of the springy things had jammed part of the ring gear. I suppose it depends on what kind of plate you have fitted. If I were even a little concerned I would change it if you are still doing the Ouse etc as even though we cant cover ourselves however good at maintainance we are for every eventuality losing drive on such locations would be an arse clenching situation!

That's a bit concerning as I'd always assumed that if I lost the drive plate, I'd still be able to run the engine to keep all the electrics running. On the other hand my Gosty tunnel experience would suggest that, even if changed under a 'preventative maintenance' regime, a log between the prop and rudder cup causing the engine to stall immediately, would be a bit of a 'test' for even a new drive plate. Luckily, my drive plate survived the experience, but it could just as easily have failed at that point. I would agree though that being out on a tidal river, on an ebbing tide, would be a bit of a 'concern' with no power to turn into a lock.

1 hour ago, Tony Brooks said:

To further rub salt into the wound if you had proper marine engines designed for the job drive plates would be very unlikely to come into it, far too unreliable for sea work.

Point of order m'lud, I ain't  going to sea in mine, does that count?

1 hour ago, Bloomsberry said:

There is a rattling noise from the gearbox/driveplate area on my boat, I've had the noise for 2 years now.

 

Gearbox is a borg warner 71C and acts as the front engine mounts so taking it apart in situ is not an option, I think the engine will need removing.

 

I have parts replacement cover with RCR but they will only attend on a complete failure so have the choice of either sorting it out myself or waiting until  failure and contacting RCR.

Wait for failure and let RCR supply the new gearbox (if necessary). Just don't risk a tidal river

[Tony Brooks]

12 hours ago, Bloomsberry said:

There is a rattling noise from the gearbox/driveplate area on my boat, I've had the noise for 2 years now.

 

Gearbox is a borg warner 71C and acts as the front engine mounts so taking it apart in situ is not an option, I think the engine will need removing.

 

I have parts replacement cover with RCR but they will only attend on a complete failure so have the choice of either sorting it out myself or waiting until  failure and contacting RCR.

If its a steel narrowboat, then a jack under the sump with a wooden p[ad on the sump would allow the gearbox to be taken off without removing the engine. If GRP the a pd under the jack may allow it or a strap around the engine to a strong beam across the boat's structure and the lift/wedge one end of the beam.

[LEO]

HI,

I had problems with the drive plate on our first boat, It coupled a BMC 1.5 to a large Thamesway Gearbox. This had an input shaft with very small splines (more akin to a car shaft), if tickover was not fast enough it used to wear away the splines on the drive plate and shaft very rapidly, result - no drive.

 

I changed the gear box to a Hurth 150 and the problem was solved.

 

Have attached a few pictures, a Hurth shaft (which is in good condition) is available to anyone who wants to pay postage.

 

 

 

Edited September 3, 2018 by LEO

[Wanderer Vagabond]

1 hour ago, LEO said:

HI,

I had problems with the drive plate on our first boat, It coupled a BMC 1.5 to a large Thamesway Gearbox. This had an input shaft with very small splines (more akin to a car shaft), if tickover was not fast enough it used to wear away the splines on the drive plate and shaft very rapidly, result - no drive.

 

I changed the gear box to a Hurth 150 and the problem was solved.

 

Have attached a few pictures, a Hurth shaft (which is in good condition) is available to anyone who wants to pay postage.

 

 

 

Was that splined shaft actually designed to fit the splines on the plate? they look different sizes (or it might just be the photo).

[Tony Brooks]

8 minutes ago, Wanderer Vagabond said:

Was that splined shaft actually designed to fit the splines on the plate? they look different sizes (or it might just be the photo).

I don't know for sure but I think the  drive plate in the photo was one that stripped its splines in the TMP gearbox with the idiot very fine splines but I could be wrong about that.

[LEO]

Sorry I did not make it very clear, the drive plate was stripped by an input shaft (not shown), the shaft pictured is from a Hurth gearbox which replaced the original engineering mess, which had led to a breakdown at Days lock on the Thames in 1989. A lady gave us a tow up to Oxford, She had a cottage and mooring just above Hambleden lock and lets us use it for a month a year (FOC) until her death in 1996...every cloud has a silver lining.