Manually turning props on inboard

B

Bob Ware

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How easily should one be able to turn the props on inboards -- marine gear in neutral? (engines off of course)....
Had a diver clean the hull and reported one fairly easy to turn but the other would barely move.
 
Pretty easily. While anchored I can reach down with my foot and turn my 18" props pretty easily.
 
I can also turn my shaft by hand at the coupler from inside the boat.
 
Yeah, maybe a fouled cutlass bearing? But shouldn't the diver have noticed if it was fouled while he was investigating? Can you easily pop the shaft loose to see if it's in the drive train?

What kind of condition are the stuffing boxes and shaft packing in?
 
Have you adjusted the stuffing box on that side too tight?
 
Thanks for the feedback guys. To answer your questions and some background.
The boat has been sitting for a while due to life getting in the way. Ran the engines periodically but we hadn't taken her out until last week.

The diver did not see anything which gave the impression there was any problem with the cutlass bearing or other fouling. In fact, I had him return to confirm no play in the shafts, etc. after hearing a screeching on the port engine/shaft a few days after the cleaning.

I haven't checked the stuffing boxes yet but considered that as a possible problem so it's on the list of things to do.

I haven't attempted turning from inside but will do that later today or Saturday.

The interesting/odd thing is the screeching came from the port engine/shaft but the starboard shaft is the one which is hard to turn and we ran her on the starboard engine for a couple hours last week after hearing the noise on the port side. It ran fine, nothing unusual.

Appreciate the help.
 
Dry stuffing boxes? Generally shafts should turn smoothly from the prps. Inside probably will be difficult.
 
Do inspect engine mounts and if the problem persists after a little running alignment should be checked.
 
I hope to get some run time this weekend so hopefully if it's dry stuffing box this will help. I'll report back next week with how things go after our next check run/outing.
 
Normally when I periodically start the engines I will bump 'er in and out of gear to spin the shafts a bit. Our lines hold us in place so if you try this make sure the lines are adequate and ready for the task. Be ready to go neutral if the SHTF.
 
If you can reach both shafts/stuffing boxes while underway you can check the heat on both. If one is hotter than the other I would check the packing. There should not really be any heat. Good luck
 
Thanks guys.
Reaching them while underway is a very tight fit but I'll attempt it. Hopefully, no hands will be lost in the attempt. [G]
 
Actually, you can do that at the dock. I was going to go with upgraded packing material vs. dripless. We launched and I put the boat in gear at the dock. After a minute in gear it was obvious the packing was too warm and there was no room to loosen it up more. I know, sounds strange but we hauled out pulled the new packing glands and went to dripless.
 
Which packing did you use? I was searching/reading earlier today about the some of the newer materials creating more heat. with no room to loosen does that imply to many layers of packing material (i.e. 4 instead of 3)??
 
Bob, My silverton 34 has 1 1/4 inch shafts and the stuffing boxes are the flange type. Mine use 3/16" packing and they hold 6 or 7 rings each. I've been using GFO packing which they claim doesn't need to drip. Keeps my bilges dry. I can not turn either of my shafts from inside with bare hands, both turn freely by the props, especially when wet. The glands should not be hotter than 125 degrees according to George Van P when I asked him a few years ago. Should be able to hold your hand on them at cruise without burning your skin.
 
Adding to the above suggestions, next time you have the boat hauled, carefully check the struts to see if they are still positioned exactly symmetrically. There are a number of reasons they can get bent to add considerable shaft friction at the cutlass.

And if the shaft donut anode has ever slipped to grind itself down against the strut anode particles may have lodged between cutlass & shaft. If you suspect that at all , best to back off the shaft and inspect for scoring there that can weaken it.
 
Sandy, you are correct about the struts. I had a bent strut once which was very difficult to appreciate. It did exactly as you say.
 
Put a torque wrench on the shaft nut IN THE WATER. If its less than 5 foot pounds of torque and shaft log is not getting hot - ignore it.
 
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