Noise aft of PSS

[bertboyer]

We recently purchased an Olson 34 and had the PSS dripless shaft seal replaced as well as new engine mounts. All engine fluids have been replaced.

All was well while motoring from the yard to our marina and then the boat sat for 7 weeks while we were out of town. Last week we motored out and noticed a squeaky sound aft of the engine and PSS and slight jerky propulsion when motoring above 1500 rpm. The engine compartment purrs and the noise seems aft. After putting the gear in reverse for a minute, the noise was gone briefly and then returned. The cutless bearing was good at the marine survey. Besides burping the dripless again, does anyone have suggestions as to what the problem might be?

I am very new to boat maintenance, but eager to learn!

Thanks!

 

[Loren Beach]

Hmmm. Kind of difficult to diagnose, even tho your description is detailed.
Probably not related, but we have noticed a faint whine from the area of/near the cutlass bearing, for about 20 years. The yard guys have guessed that it's a harmonic of some sort since it appears at low rpm's and goes away above about 1800. The condition of the cutlass bearing seems to have no effect on this. I have often wondered if other boats experience anything like this?!
BTW, if there is any "jerky" sort of movement, I would usually (re) check the alignment and also want to have a close look at the mounts. We once had a worn out rear mount that was down to metal on metal, and those rear mounts are really difficult to get a look at.

 

[Frank Langer]

We recently purchased an Olson 34 and had the PSS dripless shaft seal replaced as well as new engine mounts. All engine fluids have been replaced.

All was well while motoring from the yard to our marina and then the boat sat for 7 weeks while we were out of town. Last week we motored out and noticed a squeaky sound aft of the engine and PSS and slight jerky propulsion when motoring above 1500 rpm. The engine compartment purrs and the noise seems aft. After putting the gear in reverse for a minute, the noise was gone briefly and then returned. The cutless bearing was good at the marine survey. Besides burping the dripless again, does anyone have suggestions as to what the problem might be?

I am very new to boat maintenance, but eager to learn!

Thanks!

I'm sorry to hear of your difficulties when it seems you've tried to do everything right.
The combination of squeaky sounds and jerky performance may be a challenge to solve, so you may have to check various things. Having the boat sit unused for seven weeks is also not usually ideal (though often necessary).
I would start by carefully checking the propeller/ cutless bearing/ prop shaft in the water to ensure there's no barnacle or other growth and turning the prop in the water to see if it rotates freely in neutral gear, engine not running. If it doesn't spin easily, I would check engine alignment-- that's usually recommended anyway after a haulout as the hull shape changes as it settles in the water. Faulty alignment could well be the cause of your problems. Next I would replace the transmission fluid unless it's fairly new. This is often neglected because access is sometimes not easy, but new tranny fluid can make the tranny/ drive train operate more smoothly.
Finally, I would recheck the tension on the newly installed PSS, as the yard may have installed it with too much pressure. The techs at PSS are very helpful, and will recommend that you use new set screws (2 with 2 more on top to secure them).
Good luck and keep us posted.
Frank

 

[Loren Beach]

Next I would replace the transmission fluid unless it's fairly new.

On our former M25XP diesel, I would temporarily unbolt the two brackets from the ball housing and/or remove the two hose clamps that were holding the heat exchanger very inconveniently in place right over the trans dip stick.
If you search this site for 'transmission dip stick' you should find some good threads, also.

 

[Alan Gomes]

We recently purchased an Olson 34 and had the PSS dripless shaft seal replaced as well as new engine mounts. All engine fluids have been replaced.

All was well while motoring from the yard to our marina and then the boat sat for 7 weeks while we were out of town. Last week we motored out and noticed a squeaky sound aft of the engine and PSS and slight jerky propulsion when motoring above 1500 rpm. The engine compartment purrs and the noise seems aft. After putting the gear in reverse for a minute, the noise was gone briefly and then returned. The cutless bearing was good at the marine survey. Besides burping the dripless again, does anyone have suggestions as to what the problem might be?

I am very new to boat maintenance, but eager to learn!

Thanks!

Maybe not the most likely cause, but perhaps you have some kelp caught on the prop? That's happened to me many times over the years, and it can cause some strange behaviors

 

[Prairie Schooner]

Bert, did they install the vent tube on your PSS? You've got some good leads up above here. Good luck!

 

[Christian Williams]

You have a fixed prop, yes? (not a folding or feathering prop)

Consider the transmission. When issue develops, test with RPM and forward and reverse.

Squeaking can be raw water or coolant water pumps or alternator belt. Can be intermittent.

i would crawl into the engine bay for close observation/listening, if you can do that on an 034. This sort of thing can be notoriously hard to isolate and may be of no consequence, but drives everybody crazy, so welcome to the club.

As was said, cutlass comes to mind, and so does bent prop shaft,but can be put out of mind by visual and simple manipulation, as you've done.

To me, dripless issue seems unlikely.

 

[JSM]

You mention new motor mounts. Are they softer than the old ones perhaps allowing the engine to slightly shift from torque forces over 1500 rpm ?
You also may need to realign the engine after the new mounts have settled in.
As mention above check the trans fluid level if the yard changed it. If they didn't change it do it yourself.
(Especially if its a Hurth HBW 50 )

 

[Dave G.]

You don't mention any vibration so "Squeaky" sound leads me to the dripless. Burp/flush it good to be sure there isn't any debris stuck on the surfaces. Do you know if the dripless is getting HOT to the touch ? If so it's not getting water flow.

 

[bertboyer]

Thank you ALL for your helpful suggestions. Let me try to respond to a few of your comments below. Further advice is most welcome.

Rechecking alignment and the mounts: Apologies for my novice mechanical background...but how do I recheck alignment while the boat is in the water? I can definitely look at the mounts and ask the yard whether they are softer than the old ones. I do know that the new ones are Westerbeke engine mounts (32013). Unfortunately I don't know anything about the old ones except that the engine survey said they were "fairly solid...but that the rubber portion was starting to break down and may not provide proper vibration dampening." This was discovered soon after we made an offer on the boat and since it was already on the hard for bottom painting, we had the yard replace them. They said that they checked alignment on the hard, as well as in the water after 24 "hours splash."

Barnacle growth or kelp or other detritus: The boat is in fresh water but we have had a lot of debris copming down the Columbia river during spring thaw. I'm not a diver but others in our club said they are getting together to have a diver come out and clean the bottom. I will definitely have them inspect the prop (which is a folding prop), as well as turn it from inside the engine bay.

Transmission fluid: When on the hard, I had the yard remove and replace engine oil, several filters (oil, fuel, air, water), impeller, engine anodes and alternator belt (which sounded normal to me and tension seemed fine). I actually don't see transmission fluid listed on the invoice and I'll check it anyway and ask the yard if it was replaced. Thanks Loren for the tip on removing the heat exchanger. Christian mentioned testing the transmission in fwd and reverse. Can you provide a bit more detail re what to look for?

Tension, burping and vent tube on the PSS: We had significant PSS maintenance done including removing the coupler fasteners and removing the coupler from the shaft, removing the old PSS assembly and resurfacing the SS rotor, setting new PSS seal compression, and checking engine alignment. Everything on our 4 hour motor return from the yard sounded fine. However, when I crawled in the aft cabin to directly look at the PSS and engine while motoring Sunday, I could hear the squeaking noise aft of the PSS (but I can only see a couple feet aft). I can reach out to PSS techs to see how to check the tension. The engine seemed to sound fine with no extra vibration. There is no vent on the PSS. it is plugged. I tried to look online to see how to burp it but it must be so obvious everyone (but me) knows exactly how to do it. I can ask a couple others near our boat, but I think I have seen it done in one of Christian's videos. I will feel to see how warm it is after motoring a bit when we head out next.

Many thanks!!

 

[Frank Langer]

Thank you ALL for your helpful suggestions. Let me try to respond to a few of your comments below. Further advice is most welcome.

Rechecking alignment and the mounts: Apologies for my novice mechanical background...but how do I recheck alignment while the boat is in the water? I can definitely look at the mounts and ask the yard whether they are softer than the old ones. I do know that the new ones are Westerbeke engine mounts (32013). Unfortunately I don't know anything about the old ones except that the engine survey said they were "fairly solid...but that the rubber portion was starting to break down and may not provide proper vibration dampening." This was discovered soon after we made an offer on the boat and since it was already on the hard for bottom painting, we had the yard replace them. They said that they checked alignment on the hard, as well as in the water after 24 "hours splash."

Barnacle growth or kelp or other detritus: The boat is in fresh water but we have had a lot of debris copming down the Columbia river during spring thaw. I'm not a diver but others in our club said they are getting together to have a diver come out and clean the bottom. I will definitely have them inspect the prop (which is a folding prop), as well as turn it from inside the engine bay.

Transmission fluid: When on the hard, I had the yard remove and replace engine oil, several filters (oil, fuel, air, water), impeller, engine anodes and alternator belt (which sounded normal to me and tension seemed fine). I actually don't see transmission fluid listed on the invoice and I'll check it anyway and ask the yard if it was replaced. Thanks Loren for the tip on removing the heat exchanger. Christian mentioned testing the transmission in fwd and reverse. Can you provide a bit more detail re what to look for?

Tension, burping and vent tube on the PSS: We had significant PSS maintenance done including removing the coupler fasteners and removing the coupler from the shaft, removing the old PSS assembly and resurfacing the SS rotor, setting new PSS seal compression, and checking engine alignment. Everything on our 4 hour motor return from the yard sounded fine. However, when I crawled in the aft cabin to directly look at the PSS and engine while motoring Sunday, I could hear the squeaking noise aft of the PSS (but I can only see a couple feet aft). I can reach out to PSS techs to see how to check the tension. The engine seemed to sound fine with no extra vibration. There is no vent on the PSS. it is plugged. I tried to look online to see how to burp it but it must be so obvious everyone (but me) knows exactly how to do it. I can ask a couple others near our boat, but I think I have seen it done in one of Christian's videos. I will feel to see how warm it is after motoring a bit when we head out next.

Many thanks!!

Lots to think about! Regarding the engine alignment, there are good you tube videos showing how to check and adjust alignment. But a simple way to do a quick check is to spin the prop shaft either inside the engine compartment or at the prop in the water. If it spins easily, the alignment is probably ok; if there is resistance, it needs attention.
PSS tech staff can advise on how to burp the shaft seal and check tension.
Fresh and raw water pump squeal and fan belt squeal can all be heard readily by running the engine in neutral and listening at the front of the engine where those parts are.
I would definitely think about replacing the tranny fluid if it's not on the invoice-- many owners ignore this maintenance because access can be awkward.
Frank

 

[Kenneth K]

Burping the PSS:

The yellow arc is where the carbon seal seats against the stainless steel ring. The pressure from the compressed bellows forces the carbon seal tightly against the SS ring--this is what forms the seal to prevent water from entering the boat.

To burb the seal, grab the carbon ring and push it aft to further compress the bellows (like the blue arrow). You might be surprised how much water enters--remember, the water is "pressurized" compared to the empty space inside the hull. If there's marine growth around the seal, you can run a washcloth around the seal face while you're burping it. You might want to cover the shaft coupling/transmission to keep it from getting splashed.

 

[Dave G.]

If the bellows are new you may need a tool to break that seal. A putty knife(carefully) worked well for me. To check compression you would have to loosen the collar and reset, which means replacing the set screws as they are single use according to PSS. Compression on a 1" shaft is 3/4". If it's not leaking at all I'm sure a good burp may fix your squeak issue.

 

[Loren Beach]

Trivia- the aft bottom profile is considerably flatter on the Olson's than it is for the Ericson's. Result is that "burping" out air is seldom needed. i.e. that shaft angle is not too severe.
I have found that when I performed this ritual after launching just because of that general opinion, I got nothing but water coming out around the seal; no noticeable air escaping at all. YMMV.

 

[Frank Langer]

Trivia- the aft bottom profile is considerably flatter on the Olson's than it is for the Ericson's. Result is that "burping" out air is seldom needed. i.e. that shaft angle is not too severe.
I have found that when I performed this ritual after launching just because of that general opinion, I got nothing but water coming out around the seal; no noticeable air escaping at all. YMMV.

On my 1984 E30+ I have never noticed air either when burping the shaft seal, just a quick rush of water. I'm not sure that one would ever be able to hear or notice air--I think the amount of air to be displaced by water is small.
Frank

 

[JSM]

Apologies for my novice mechanical background...but how do I recheck alignment while the boat is in the water?

Alignment is the alignment of the two halves of the coupling that connect the transmission and the drive shaft. If the engine is tilted the slightest bit too far up, down or left or right it results in the drive shaft wobbling creating vibration. The shaft may turn freely by hand but at certain RPM's vibration will be transmitted into the hull.
Alignment should only be done in the water when the hull regains it's natural shape after being on jack stands. It is done by removing the bolts that hold the two halves of the coupling together and checking the clearances at the top, bottom and left and right sides with a feeler gauge. Clearance should be no more than about .003 of an inch difference between those points. Adjustment is made using the adjustment nuts on each motor mount. It's an extremely tedious process !
After re reading your original post it sounds like alignment may be lower on the list as the cause of your noise.

 

[Dave G.]

Trivia- the aft bottom profile is considerably flatter on the Olson's than it is for the Ericson's. Result is that "burping" out air is seldom needed. i.e. that shaft angle is not too severe.
I have found that when I performed this ritual after launching just because of that general opinion, I got nothing but water coming out around the seal; no noticeable air escaping at all. YMMV.

You are just evacuating the air in the shaft log so water can get to the seal. Otherwise you may have a airlock inside the log which will stop ANY water getting up to seal. I don't think a flatter hull mitigates the need of burping the seal IMHO.

 

[bertboyer]

Lots to think about! Regarding the engine alignment, there are good you tube videos showing how to check and adjust alignment. But a simple way to do a quick check is to spin the prop shaft either inside the engine compartment or at the prop in the water. If it spins easily, the alignment is probably ok; if there is resistance, it needs attention.
PSS tech staff can advise on how to burp the shaft seal and check tension.
Fresh and raw water pump squeal and fan belt squeal can all be heard readily by running the engine in neutral and listening at the front of the engine where those parts are.
I would definitely think about replacing the tranny fluid if it's not on the invoice-- many owners ignore this maintenance because access can be awkward.
Frank

Thanks Frank!

I'll look for some videos as you suggested and also spin the prop shaft. I didn't see any wobbling or vibration while underway. I asked the yard if they replaced transmission fluid. If not, I will do it! I will also burp the PSS.

 

[bertboyer]

To burb the seal, grab the carbon ring and push it aft to further compress the bellows (like the blue arrow).

Ken,
Thanks so much. This is very helpful!!

 

[bertboyer]

Alignment should only be done in the water when the hull regains it's natural shape after being on jack stands. It is done by removing the bolts that hold the two halves of the coupling together and checking the clearances at the top, bottom and left and right sides with a feeler gauge. Clearance should be no more than about .003 of an inch difference between those points. Adjustment is made using the adjustment nuts on each motor mount. It's an extremely tedious process !

Thank you. Let me work through some of the other options first as this seems pretty technical!