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a64pilot 17-04-2020 06:30

Re: Flex Plate Failure
 
1 Attachment(s)
Quote:

Originally Posted by Bill O (Post 3118837)
A64,
Glad to hear you made it back in one piece and it wasn't your flex plate after all.
Did you have enough wind to sail a significant amount or was it the motorsail as you suspected it would be?

Motor sailed a lot of it, and then my main broke, the loop at the top where it attaches to the halyard broke, I could have affected a field repair, but the Halyard is stuck at the top of the mast, and I’m not going up the mast at sea, I’m way too old or not nearly manly enough for that.
Wind and seas were light at the beginning and then about the time we came off the bank wind picked up to about 25 kts true from the South and I had to take the code zero down and finish with the Genoa. We came straight from New Providence to Lake Worth, about 25 hours. Without a main it was very rolly.

Mack Sails is coming up to Ft Pierce on Mon to get the main, I don’t like the St Lucie inlet, it was my first grounding.

Bill O 17-04-2020 07:22

Re: Flex Plate Failure
 
Agree, going up the mast in open water is a young man's sport and it only takes one time up to remember the bruises for a long time.

Your webbing looks like what we have on our genoa, but our main still has a head board and the halyard is shackled to the main. That said, I have blown the main halyard before (on a different boat), so we made our topping lift as our spare main halyard. Never had to use it (so far), but nice to have an alternate and don't have to go up the mast in a rolly anchorage.

Hoping you timed the Ft. Pierce entrance well, as we have seen that entrance piled up w/opposing current/wind.

a64pilot 17-04-2020 07:28

Re: Flex Plate Failure
 
Quote:

Originally Posted by Bill O (Post 3118914)
Agree, going up the mast in open water is a young man's sport and it only takes one time up to remember the bruises for a long time.

Your webbing looks like what we have on our genoa, but our main still has a head board and the halyard is shackled to the main. That said, I have blown the main halyard before (on a different boat), so we made our topping lift as our spare main halyard. Never had to use it (so far), but nice to have an alternate and don't have to go up the mast in a rolly anchorage.

Hoping you timed the Ft. Pierce entrance well, as we have seen that entrance piled up w/opposing current/wind.


My topping lift is a cable and can’t be used as a spare Halyard, hadn’t thought of that, that is a good idea.

High tide for Ft Pierce on Sun is 1900, I should be there about 1600 or so, so I should arrive during an incoming tide, so it should work for me, I have come in through there on an outgoing tide and it was slow, rage wasn’t too bad though.

Bill O 17-04-2020 07:37

Re: Flex Plate Failure
 
Quote:

Originally Posted by a64pilot (Post 3118927)
My topping lift is a cable and can’t be used as a spare Halyard, hadn’t thought of that, that is a good idea.

The static cable/wire was our topping lift arrangement before also. Luckily we had an "extra" sheave (that was probably used by a PO for a topping lift), so our re-rig for the spare wasn't too complicated.

JPA Cate 17-04-2020 14:26

Re: Flex Plate Failure
 
@A64pilot,

There is spectra stropping available for the head of the mainsail, you'll have to specify it, though, but is way more chafe resistant than polyester webbing.

Ann

a64pilot 17-04-2020 14:42

Re: Flex Plate Failure
 
Quote:

Originally Posted by JPA Cate (Post 3119415)
@A64pilot,

There is spectra stropping available for the head of the mainsail, you'll have to specify it, though, but is way more chafe resistant than polyester webbing.

Ann

Thank you, Iíll ask about it. Hoping Mack Sails will pick up our main sail on tues. Iím traveling up the ICW to Jax then and wonít really need it then.
I donít think chafe got it, I think stress over time did, I believe you have to keep the halyard tight on a sail that has a bolt rope in a track or the bolt rope wears excessively, at least mine did until I started keeping the halyard tight, probably too tight.
Iím still learning remember.

a64pilot 17-04-2020 14:46

Re: Flex Plate Failure
 
Quote:

Originally Posted by Bill O (Post 3118944)
The static cable/wire was our topping lift arrangement before also. Luckily we had an "extra" sheave (that was probably used by a PO for a topping lift), so our re-rig for the spare wasn't too complicated.

I donít have an extra sleeve on the rear, so we ran the spare halyard off the front. I would like to have a topping lift that I could adjust from the cockpit, but without a shelve I canít or donít think I can anyway.

NNBill 20-04-2020 07:23

Re: Flex Plate Failure
 
For those people that do need to change the flex plate on a Yanmar 4JH**.
(1) There is no "automotive" equivalent drive plate. Automotive use is either a solid sheet steel plate with the ring gear around it that bolts to the crankshaft, then the torque converter bolts to it for an automatic transmission. The torque converter actually supplies the mass to dampen the engine pulses. A manual transmission has a true heavy flywheel that the clutch pressure plate bolts to. Then between the flywheel and the pressure plate is the clutch disk, which has a spline in the center to drive the transmission. The marine damper plate bolts to the heavy flywheel then has the splined hub in the center for the transmission input shaft.
(2) The bell housing does NOT have to come off to access the damper. You do need a gap of atleast 4 inches to comfortably pull the transmission out of the damper. Fortunately the Yanmar/Kanzaki transmission is a relatively light transmission, unlike a Borg Warner Velvet drive on the back of a 4JH. :(
(3) Most of the time, the manufacturer of the drive plates is Sachs. Sometimes depending on the engine / transmission combination you can find them aftermarket instead of through Yanmar. There are also a couple of different aftermarket drive plate manufacturers too. I've always gotten replacement Yanmar drive plates through Mack Boring in NJ, they seem to have the best price.
(4) Don't forget to grease / Never seize the heck out of the transmission splines, it is a royal pain to remove a transmission when the input shaft has rusted and seized in the damper spline!!!

Capt.Don 20-04-2020 07:31

Re: Flex Plate Failure
 
I have exact same issue, Iím not convinced itís a flexplate, though. At low RPM the engine shakes,which could be the source of the sound. I may buy a spare flexplate, as parts are hard to source in Mexico, once we get home in the summer. Very interested in this thread.
Don

Bill Schmid 20-04-2020 09:24

Re: Flex Plate Failure
 
I lost my damper plate in the Chanel lslands. We sailed to Ventura l called around local couldnít find one . I called a Harbor Marine in Everett , Washington they hah it on the shelf and sent down to me.

a64pilot 20-04-2020 09:32

Re: Flex Plate Failure
 
Quote:

Originally Posted by Capt.Don (Post 3121654)
I have exact same issue, I’m not convinced it’s a flexplate, though. At low RPM the engine shakes,which could be the source of the sound. I may buy a spare flexplate, as parts are hard to source in Mexico, once we get home in the summer. Very interested in this thread.
Don

Engine shaking at low RPM could be mounts, it could also be dirty injectors and even too tight valves, anything that could cause a miss. Even could be an alignment issue.
It could even also be a harmonic vibration, every system has certain RPM’s that will match up with the natural frequency of the drive train and when you get there, it will set up a vibration that will increase until it’s dampened out.
All you can honestly do is change that harmonic frequency by adding or removing mass of rotating components etc, or most of us just avoid the RPM ranges that the motor/drivetrain vibrates at, just transition through them.
I think I may also buy a spare drive plate and add it to the $$$ of spares I carry around. At 33 yrs old, it has to be getting pretty bad, and the heavy mass of the prop I have has to stress it too in shifting etc.

But I’m fairly certain my problem is the prop, if you put your ear to the transom and listen, you can hear the prop “rumble” sort of at cruise. The initial rattling is what had me thinking flex plate, cause I swear it sounded just like broken clutch springs, and if I understand correctly a flex plate is pretty much exactly a clutch, just no friction material, and it’s bolted firmly to the flywheel as opposed to being squeezed onto it by a pressure plate.

Capt.Don 20-04-2020 10:46

Re: Flex Plate Failure
 
Back to the flex plate discussion, once the housing is removed the 2 to 3 inches, does the flex plate just slide off the shaft?
Thx, Don

a64pilot 20-04-2020 11:36

Re: Flex Plate Failure
 
I have not done it, but nearly certain that you remove the transmission bolts and slide it out of the flex plate, again exactly like a clutch, difference I guess is that a clutch has to be aligned where a flex plate being mounted directly to the flywheel doesn’t require it.
Assuming of course it hasn’t seized in place, which could be a real bear if it has, if it has I guess you start the penetrating oil thing.

So disconnect and slide the shaft back 5 or 6 inches, then disconnect the shifter cable and disconnect the cooler lines if you have them, unbolt the tranny and slide it back off of the flex plate and if you desire remove it.

Now just from looking this is where the Marine transmission differs from an auto, the Marine transmission’s mount plate on the front is so large it allows access to the flex plate without removal of the bell housing, where an auto has to have the starter removed, and also the bell housing, and often on a car the flywheel comes off to be resurfaced, but not a marine set up.
So if I’m correct there are many, many similarities, but the Marine flex plate is actually much simpler than the clutch on a car.
The shaft on a transmission with a clutch has a pilot bearing in the crankshaft, I assume as the flex plate is always firmly connected, there is no pilot bearing?

Joe Okros 20-04-2020 12:39

Re: Flex Plate Failure
 
Well, mine was doing this when I bought my boat 16 years ago, Borg Warner on a 4108. The Perkins guy in St Maarten told me they all do that and not to worry about it. 16 years later and half a world away in NZ it's still doing it so I take his advice and don't worry about it.

NNBill 20-04-2020 15:02

Re: Flex Plate Failure
 
Quote:

Originally Posted by Capt.Don (Post 3121814)
Back to the flex plate discussion, once the housing is removed the 2 to 3 inches, does the flex plate just slide off the shaft?
Thx, Don

As A64Pilot stated, the damper plate stays with the flywheel, the splined input shaft of the transmission pulls straight out of the damper plate, then you unbolt it from the flywheel.


Bill.


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