Props should turn with one hand?

We recently had our first haulout on our loop trip to deal with what turned out to be only one faulty through hull so that was good news. The rest were inspected and serviced. While in the yard we got a few other projects done but the main reason for this post is to get a feel for what I just told.

Our port prop was dinged up in a few places. I had not noticed any cavitation and maybe you wouldn’t on props this size but I’m new to Boating in this 42 foot range. Anyway, they did pull that prop and found a local shop able to rework it in a quick turnaround. They don’t work weekends however one of the workers was there just now and we had a chat. He casually mentioned we need to think about having the shafts checked and Cutlass bearings replaced because neither prop can be turned by hand and you should be able to. These are twin 120 Lehmans and if one needs me to measure the props I can do so and re-post.

I have no reason to not trust these people but I also am aware of how limited I am in my knowledge on these things. I get that if that is a fairly common litmus test then we failed it because I even tried to do it by hand myself and neither would budge. This guy wasn’t even confident we could stay beyond Monday morning and have this analyzed because the yard is pretty busy and on a schedule. My wife and I at first blush thought why would we leave to continue our trip knowing we should be planning another haul out soon or fairly soon?

I’m interested in hearing thoughts on where we are as we need to make a decision from our end by Monday morning and then find out if we’re staying if they can even allow us to do so. Additionally we aren’t allowed to stay on board so we would need to try and extend our short term housing situation.

As always I look forward to the tidbits of wisdom that come from this group.

Being totally unable to turn the props by hand seems like excessive drag somewhere in the shaft line to me. Right after haulout I can easily turn both of my props one handed. It gets a little harder after a day or 2 once the cutlass bearings dry out, but they still turn fairly easily without loosening the stuffing box packing or anything.

Both of mine turned easily on survey hang. Surveyor said that's good, means the bearings are good and the shaft is straight.

Aside: This reminded me that I often see people say both “cutlass bearing” and “cutless bearing” and have wondered which is correct and why. So I looked it up and found this:

https://www.seattleyachts.com/news/its-correct-name-is-a-cutless-bearing

Delta Riverat said:

Both of mine turned easily on survey hang. Surveyor said that's good, means the bearings are good and the shaft is straight.

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AND the whole of the shaft, cutless bearings and supports, engine are in good alignment.

Did you try to turn them?

There's a big difference between turning the shaft and turning the propeller. If you can't turn the shaft grabbing the blades of the propeller, you probably have an issue. Grabbing the shaft and trying to turn it with dry cutlass bearings is very difficult.

Keep in mind, some boats flex when out of the water and possibly not blocked correctly. Also, your shaft and cutlass bearings may be fine, but the engine motor mounts may need to be adjusted.

As a general rule, before I haul out, while sitting in the slip, I turn the shaft after the transmission by hand. Usually I turn the shaft coupling with a wrench first, and then turn the shaft by hand. It's not easy, and will only turn very slowly. It you can't do that, then try turning the shaft with a strap wrench.

I only have one cutlass bearing on my shaft. So with the propeller off, I try to move the shaft up and down, and to port and starboard to check for cutlass bearing wear.

If you're going to have someone else check it, make sure they are a professional with lots of experience. You can throw an awful lot of money at the wrong parts or a problem that doesn't exist.

Ted

Some boats distort an bit when out of the water dependent upon how they’re lifted and blocked. Thus shaft rotation may be tighter. Once in the water things line up per previous alignment efforts.

What kind of boat and is it cored or solid FRP?

A "cutlass" is a sword, while "Cutless" is actually a name brand of BF Goodrich. We all know what it is, but using the name universally is like calling all colas "Coke". The people at Pepsi hate that. There are other companies besides Goodrich making them, and of course they can't call them Cutless bearings. The generic term is "stave bearing." I was surprised they didn't say that in the article.

It is a Grand Banks 42 and is Glass. Also to clarify on a question here yes, I did try and turn the props by hand.

Also, great suggestion on trying to remember to turn them before every haul out to assess and then probably even immediately after before dry out begins.

Yes holding the tip of the prop you should easily be able to turn the shaft. Maybe a brief sticking if dry.
If not disconnect from the transmission coupler and try again. If it moves freely, engine alignment, if not then those cute less stave bearings (cutless) or bent shaft.

jgwinks said:

A "cutlass" is a sword, while "Cutless" is actually a name brand of BF Goodrich. We all know what it is, but using the name universally is like calling all colas "Coke". The people at Pepsi hate that. There are other companies besides Goodrich making them, and of course they can't call them Cutless bearings. The generic term is "stave bearing." I was surprised they didn't say that in the article.

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If you read down further in the article you quoted from, the term cutlass bearing is in wide use and only the manufacturer who has copyrighted the Cutless name seems to have a problem with using cutlass. As I was referring to the generic widely recognized term as opposed to the name brand, I'll stand by what I wrote.

Ted

The bearings might be fine, tightness is not the usual reason to replace, wear is. Tightness may suggest other checks, unfortunately alignment should be done in the water.

Shaft diameter past 2 to 3 inches can be hard to turn dry wnen when perfect.... but 2 inches usually can be.

Sunchaser being correct with on land things get distorted sometimes.

sunchaser said:

Some boats distort an bit when out of the water dependent upon how they’re lifted and blocked. Thus shaft rotation may be tighter. Once in the water things line up per previous alignment efforts.

What kind of boat and is it cored or solid FRP?

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Darned good point.

Which is one reason to do a rough alignment on land and then after a couple of days do another of the engine to shaft alignement.

GB's are pretty stiff given the full keel. Yes, final alignment should be done in the water, but you would ordinarily be within a few thou. on land in that boat. Typically, cutless/cutlass bearing wear eccentrically so as others stated, sideways or up & down movement of the prop/shaft reveals excessive play if the bearings are worn. Inability to turn by hand on land either means a tight bearing (which you can live with presently) or misalignment of the drive train. The latter will eventually need correction-the timing of which will be determined by the degree of misalignment. If disconnecting the coupler from the tranny doesn't show misalignment (as others suggested) and there is no movement of the engine on shifting forward/reverse in the water, then the motor mounts are probably ok. If a dial gauge doesn't show excessive runout of the shafts (i.e. a bent shaft), and the shafts are just hard to turn, I would carry on as is.

Mine were hard to turn. I had to exert a lot of force, but I could turn them. I went through the papers in the boat and found that the PO had been chasing that problem and had the engine alignment re-done more than once.
I went about 20 years like that, until I was having something else done with the boat hauled, so I had the mechanic check the Cutless bearings. I was informed that, at 6000 hours, they looked like they should be replaced, so I went ahead with that. With the shafts removed, it was easy to check the alignment, so that was also trued up.
My shafts now turn with only a reasonable pressure, but I am not convinced that the stiff turning that I used to have was any sort of a problem.

For some reason sometimes the cutless bearings will swell and drag on the shaft. It happened on my boat, even when the bearing and shaft were removed you could not easily turn the bearing on the shaft. My boat has two bearings on one shaft, the aft one still turned easily, the forward one was swollen and pretty stuck. This can (and did) wear the shaft prematurely.

Hi,

This lin is cutlass tolerans index, you also need a magnet stand and a dial gauge (metal lathe tool), this tool helps to measure the movement of the shaft when you lift the shaft from the propeller.

https://www.pacificmarine.net/engin...rudder-bearings/cutless-bearing-clearance.htm

Prop Turning Hard

By now you are hopefully back in the water. This a reminder in case your yard didn't know, the props on a twin GB have different specs.

Not only should they turn by hand, if the bearings are wet, they should continue to turn at least slightly (25-45 degrees) when "spun", i.e. pulled hard with your hand.

This could be either a shaft to bearing alignment issue, a shaft to engine alignment issue (which could be causing misalignment between the shaft and the fwd bearing) or a swollen bearing issue. If you can't turn them at all, I'd lean toward the latter. I have encountered a number of swollen bearings, all non-Duramax, all-made in Asia, over the years, and as recently as just a few months ago.

Many GBs have three bearings per shaft, which can be a bit challenging to align.

More here...

Alignment https://stevedmarineconsulting.com/the-ins-and-outs-of-engine-and-shaft-alignment/

Shaft Bearings https://stevedmarineconsulting.com/cutless-bearing-etiquette-2/

Years ago I did get an email from Duramax politely reminding me that if I used "Cutless bearing" in publication, I had to include the registered trademark symbol, as they "own" Johnson Cutless Bearing https://www.duramaxmarine.com/johnson-cutless/water-lubricated-rubber-bearings.htm

I've never heard of any connection between them and Goodyear.

My prop turns by hand but very stiff. I noticed that once after I test ran the engine "on the hose, on the hard" the prop was much easier to turn. Note, I have a dripless shaft seal.

My guess is that you are OK.

pete

Prop shaft

I saw one mention about the stuffing boxes. I would check to see how tight they are. Could be they have been adjusted to tightly and if so I would have a look at the condition of the shafts as well.