Do I need a new cone clutch DP-E ?

[simonfraser]

forward engagement has been soft for years
Shrieking noise at 2k revs
shortly after engine cut out
oil pressure / temp ok
props clear

engine starts, but revs not stable and suddenly increasing
ok just if going forward v slowly
still engaging with a clunk for reverse

I assume that is a yes

so I need new forward clutch, do both or just forward ?
replace the U joint as it rumbles a bit when turning
replace which shaft seals

what else on the list ?
tnx

 

[spannerman]

Strange symptons you have here, not sure why the engine would cut out or revs are unstable, that sounds like a problem in itself. You can’t replace just the forward clutch as the clutch is a double cone unit and you can’t replace just the forward gear as the whole gear set is matched (read expensive). I would take the top gear set out and examine the surface of the cone on the gears, if its highly polished you can recut them with grinding paste and a worn clutch cone which you may have. The clutch has fine grooves around the cone part, if these are worn down then it will slip on engagement and then usually engage hard as the revs
increase. I would also check the drive plate on the flywheel as these can collapse also, you maybe able to feel if there is any slack in its splines by twisting the intermediate shaft back and forth, there shouldn’t be any slack.

 

[petem]

Simon, this doesn't sound anything like a clutch issue. It sound like the issue that I had that was due to dirty engine wiring connections plus a knackered battery.

First thing I'd do is get the battery properly tested and also make sure your alternator and battery charger are working properly. Don't piss about with the engine by starting it or you may damage your ECU.

The other thing that can cause the engine to suddenly rise is a damaged turbo bearing leaking oil into the intake system.

 

[volvopaul]

forward engagement has been soft for years
Shrieking noise at 2k revs
shortly after engine cut out
oil pressure / temp ok
props clear

engine starts, but revs not stable and suddenly increasing
ok just if going forward v slowly
still engaging with a clunk for reverse

I assume that is a yes

so I need new forward clutch, do both or just forward ?
replace the U joint as it rumbles a bit when turning
replace which shaft seals

what else on the list ?
tnx

Have you ever employed a professional to work on your boat as you seem to have many issues with it looking at how many times you post on this forum ?
And yes you’re cone clutch sounds very worn .

 

[oldgit]

Forum memember had some grief with a cone, had the cone reconditioned as cheaper alternative to replacement., it completely failed to solve the problem.
The gearbox and to be removed again and new VP cone fitted.

 

[volvopaul]

Forum memember had some grief with a cone, had the cone reconditioned as cheaper alternative to replacement., it completely failed to solve the problem.
The gearbox and to be removed again and new VP cone fitted.

I cannot see who would advise on cone clutch reconditioning unless they know absolutely nothing relating to how it works .

 

[simonfraser]

Have you ever employed a professional to work on your boat as you seem to have many issues with it looking at how many times you post on this forum ?
And yes you’re cone clutch sounds very worn .

tnx, i ask lots of questions

 

[westernman]

forward engagement has been soft for years
Shrieking noise at 2k revs
shortly after engine cut out
oil pressure / temp ok
props clear

engine starts, but revs not stable and suddenly increasing
ok just if going forward v slowly
still engaging with a clunk for reverse

I assume that is a yes

so I need new forward clutch, do both or just forward ?
replace the U joint as it rumbles a bit when turning
replace which shaft seals

what else on the list ?
tnx

I had trouble engaging reverse for a while (gives some heart stopping moments when trying to park). But waiting a bit before building revs did the trick. For a while. Until one day I had to be towed to my parking spot as I was drifting helplessly through the marina. The gearbox refused to engage either forwards or reverse.

Cone was badly worn, and the thingy whatsit (damper in Catalan) to dampen the shock of engaging gear was rusted solid.

The biggest cost by far was getting the thing out of and back into the boat. My engine room is impossibly tight. I don't think mobos ever have that kind of access problem. The cone itself was about 250 euros.

 

[oldgit]

I cannot see who would advise on cone clutch reconditioning unless they know absolutely nothing relating to how it works .

Think the boat was in Dover and cone "regrinding" undertaken by some outfit in East Anglia. ?
Might have been a Corniche ?
There is Corniche for sale with one of its boxes replaced at cost of 9K, wonder if its the same boat.

 

[petem]

Does anyone care else care to give a diagnosis for Simon's screeching revs?

 

[simonfraser]

Does anyone care else care to give a diagnosis for Simon's screeching revs?

seems odd to me that i have this gear issue at the same time as the KAD 44 cutting out
if the cone did slip would that not make a nasty noise 1x at 2k revs, perhaps at the top of a torque curve ?

does the KAD have some sort of rev sensor which makes it cut out as the cone loses grip ?
could see the revs bounce around a bit and if that happened by about 200 revs the kad did cut out
we're talking 500 - 800 revs when going back to the slip, any faster and it def bounced too much and cut out

 

[westernman]

seems odd to me that i have this gear issue at the same time as the KAD 44 cutting out
if the cone did slip would that not make a nasty noise 1x at 2k revs, perhaps at the top of a torque curve ?

does the KAD have some sort of rev sensor which makes it cut out as the cone loses grip ?
could see the revs bounce around a bit and if that happened by about 200 revs the kad did cut out
we're talking 500 - 800 revs when going back to the slip, any faster and it def bounced too much and cut out

My clutch cone is immersed in engine oil, so it did not make a screeching sound.
If it is screeching - may be there is no oil in your clutch or gearbox???

 

[petem]

seems odd to me that i have this gear issue at the same time as the KAD 44 cutting out
if the cone did slip would that not make a nasty noise 1x at 2k revs, perhaps at the top of a torque curve ?

does the KAD have some sort of rev sensor which makes it cut out as the cone loses grip ?
could see the revs bounce around a bit and if that happened by about 200 revs the kad did cut out
we're talking 500 - 800 revs when going back to the slip, any faster and it def bounced too much and cut out

Are you getting the screeching / erratic revs when the boat is in gear or when in neutral too?

 

[BruceK]

Does anyone care else care to give a diagnosis for Simon's screeching revs?

A complete punt, given a few coincidences and a long lockdown and my own recent issue of belts because of.

It could be coincidence and I'm not sure what revs the SC engages all on a 44 other than it's different to the 42, but screeching noise that makes your buttocks clench can happen when the crank to waterpump belt slips when the SC engages or is under serious load. Starts as a rumble that could sound like his UJ diagnosis and develops into a banshee wail. I know it put the fear of god into me when I first heard it.

 

[petem]

A complete punt, given a few coincidences and a long lockdown and my own recent issue of belts because of.

It could be coincidence and I'm not sure what revs the SC engages all on a 44 other than it's different to the 42, but screeching noise that makes your buttocks clench can happen when the crank to waterpump belt slips when the SC engages or is under serious load. Starts as a rumble that could sound like his UJ diagnosis and develops into a banshee wail. I know it put the fear of god into me when I first heard it.

Good call Bruce. The S/C on a KAD44 engage at start-up to bring the engine up to temperature (could have explained my screech on tickover).

 

[James L]

seems odd to me that i have this gear issue at the same time as the KAD 44 cutting out
if the cone did slip would that not make a nasty noise 1x at 2k revs, perhaps at the top of a torque curve ?

does the KAD have some sort of rev sensor which makes it cut out as the cone loses grip ?
could see the revs bounce around a bit and if that happened by about 200 revs the kad did cut out
we're talking 500 - 800 revs when going back to the slip, any faster and it def bounced too much and cut out

If it was a rev sensor causing it to cut out that would happen at much higher revs and usually they would only cut back the throttle, not kill the engine.
As far as I understand it the DPE cone clutch if worn would prevent it from going into gear. I think if it was that worn that it would slip once already in gear, then it would never get into gear in the first place.

Sounds like you will need to replace the clutch anyway, but I also think you have another problem.
Where does the shreeking sound come from? Any chance it's the alternator belt? That would explain the noise and the jumping revs.

 

[westernman]

If it was a rev sensor causing it to cut out that would happen at much higher revs and usually they would only cut back the throttle, not kill the engine.
As far as I understand it the DPE cone clutch if worn would prevent it from going into gear. I think if it was that worn that it would slip once already in gear, then it would never get into gear in the first place.

Sounds like you will need to replace the clutch anyway, but I also think you have another problem.
Where does the shreeking sound come from? Any chance it's the alternator belt? That would explain the noise and the jumping revs.

Possibly just the cone.

 

[A_8]

The cone does not change with revs, it only moves when you change gears.

 

[crewejd]

forward engagement has been soft for years
Shrieking noise at 2k revs
shortly after engine cut out
oil pressure / temp ok
props clear

engine starts, but revs not stable and suddenly increasing
ok just if going forward v slowly
still engaging with a clunk for reverse

I assume that is a yes

so I need new forward clutch, do both or just forward ?
replace the U joint as it rumbles a bit when turning
replace which shaft seals

what else on the list ?
tnx

Lots of things that could cause the shrieking such as slipping drive belts, but recently extracted my engine and found the shaft that goes from the dampener (looks like the clutch plate in a car) to the out-drive had 2 seized solid bearings.
This was due to seawater ingress after a failed driveshaft bellows. I didn't hear them shriek, but expect if they turned at all, they would have protested...

 

[simonfraser]

shriek was just the once for a sec or two at 2k revs
cone engagement failed just after
VP mechanic has just had the unit appart, aparently i have the 'upgraded cone material' and it just needs lapping
def slipped as far as he is concerned

he's going to check the error codes on the KAD thursday

having the seals and gaskets replaced, incuding on the prop shaft, as it is mostly apart now

UJ bearings ok as far as he is concerned and no need to replace those