Cutlass bearing problem

[hlev00]

There may be a couple of problems but I think the worst of it may be a cutlass bearing problem.

Our Beneteau 2-cabin 423 has a Yanmar 4JH4E and a Max Prop. To feather the MP we normally 1) have the sails drawing 2) are in neutral 3) stop the engine, then 4) put the transmission into reverse. Once in reverse and the prop feathers we put the transmission back into neutral.* Normally, before feathering the prop, we hear a whirring sound of the prop free-wheeling.

We have been finding it more an more difficult to move the transmission from reverse to neutral.

Today ..
We were heading out to start a trip south from Savanah and noticed that when we first stopped the engine with the prop not yet feathered and free-wheeling, the steady whir is now accompanied by a steady thumping sound. The thumping is strongest just below the starter battery, or maybe just aft of it.[relevant mostly for 423 owners. I did post in the 423 yahoo group]

Today we could not get the transmission back to neutral after feathering unless we slowed the boat to 1-2 kts. While the transmission was stuck, I disconnected the shifter linkage at the transmission. The shifter was fine. It was the transmission that would not shift.

We noticed for the first time today that when the prop was feathered and the transmission is in neutral at 5 kts, that the prop still turns at 30-50 RPMs. I am able to stop the shaft with my hand but it starts turning again when I release it. This may not be new. I don't recall every trying this before.

In July, we had the boat out of the water to get the rudder "bearing" attended to, we asked that the yard check the cutlass bearing. They said they grabbed onto the shaft and there was no play in it.

So, primary concern is that we hear a distinct thumping when the prop is free-wheeling. Does this sound like cutlass bearing issue?

Secondary is the difficulty shifting out of reverse. Has our "putting into reverse to feather" technique damaged / worn the gears? Or, might the prop not be feathering sufficiently, thereby creating too much pressure on the gears to come out of reverse?

Thanks all,
Harry
Juno

[Compass790]

Before you read my analysis I will tell you I have no experience with a maxprop or yr particular Yanmar.
But anyway here goes. Sounds like an improper feathering problem. We have a trashed cutlass bearing but that doesn't cause the thumping sound that you describe. Just have normal self-feathering prop. Sometimes we can lessen the thumping when going in fwd by putting in reverse briefly whilst travelling at 4 knots, it then seems to make it open properly.
The other problem that causes thumping is the neutral adjusting screw on the Kanzaki gearbox. You need to adjust it according to workshop manual instructions. If the oil is cold the thickness can drag the clutch plates sufficiently to cause it to turn slowly & the blades flopping back & forth make thumping noises. This sounds like yr drive symptoms especially as you can stop the rotation by grabbing shaft.
BUT as I say I'm not familiar with maxprop so maybe someone who is will chime in & say if this is possible

[hlev00]

Updates -

Cutlass bearing seems fine. No excessive vibration during operation and the shaft is fine from inside too. The boat was hauled to look at the prop. The shaft is very solid in the bearing. As for the prop ...

Summary - the tech that disassembled my prop, for no need, didn't put it back together correctly. We are finishing putting it back together correctly tomorrow to relaunch. Hopefully all the bad noise are related and will resolve to, though I am not hopeful.

More background
We took our boat from Boston to Georgia in October and returned to it a week ago to continue south to Miami, then The Bahamas. We needed some work done while we were away. We couldn't stay to do the work and were hoping to have the boat relaunched when we arrived. One of the items was to grease the Max Prop. My expectation was that someone would squirt some grease in via the four Zerk fittings. While we were gone the tech didn't have the right Zerk (6mm thread) so instead of sending out for a set of 10 at $7 from the Autozone 1/2 mile away he took it all apart, cleaned and packed grease into it as he assembled it. In the process he left some crud in a tiny hole where a pin needs to seat. This threw off the fit enough to cause it all to be much tighter.

Lesson - no matter the reputation of the boat yard, check every bit of work done. I've re-learned this too many times.

So I don't know what will come of the shifting problem (going from R after feathering to N). It is definitely related to pressure on the gears from the prop attempting to rotate. Hopefully the prop will feather completely to stop all pressure on the gears.

As for the thumping, hopefully it is again related to the prop though I tend to think not.

I am going to try to sell the yard of pair of Zerk fittings for $1,000 each, minimum two.

More updates tomorrow or later if we manage to get offshore.

Harry

[Compass790]

Yes agree with you about quality of work by random people. I've wrkd with so many f***wits that I've come to realize that's it's a lottery getn a competent person to do your work
Glad you posted yr results so far. I still think yr problem is related to feathering as the symptoms u describe are the same as ours even tho we have probably 1/4" play in prop shaft. That prop shaft problem manifests itself in a rumbling noise whereas failure to feather is the thumping. But as I said I'm unfamiliar with yr prop so cud well b wrong.
Keep us posted

[Compass790]

I'm only vaguely familiar with American "English" so zerk fittings was lost in translation. We call them "grease nipples" FYI
So joke was lost on me.
BUT good luck with that. Seems fair to me if they reamed you.

[gmakhs]

Hello ,
You cannt go back to neutral this seems to me.like the reverse has some.load from the prop , so your prop seems to not be opening or closing properly , is the prop clean??