prop spin

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hammerhead
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prop spin

Post by hammerhead »

had boat pulled and winterized and noticed that the port prop was spinning when in neutral and at idle. what to do?
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prowlersfish
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Re: prop spin

Post by prowlersfish »

Its due to clutch drag . A sight bit is not abnormal . Was it spinning slowly vs engine speed ? Have you noticed the boat trying to move forwaed in neutral while in the water ? What trans do you have ? If you don't know what boat/ engine ?
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77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat :D
hammerhead
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Re: prop spin

Post by hammerhead »

f30 with 318's . will post video later
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Tgornik
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Re: prop spin

Post by Tgornik »

I have the same issue, and found it the same way... However, I also have a small crack in a freeze plug just outside the flywheel diameter. Water comes out, and sprays the clutch and i believe is the cause of the clutch dragging. (corrosion in the springs??)

I'm not exactly sure what to do about the clutch yet, but I know I have to pull the bell housing to fix the brass plug and was goign to address the clutch then.
"You're gonna need a bigger boat!"

1973 Trojan F31 Flybridge W/ Twin Chrysler LM 318s
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prowlersfish
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Re: prop spin

Post by prowlersfish »

There is no clutch in the bell housing . The only clutches are inside the transmission . If your getting water in there it needs to be taken care of now if not sooner
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat :D
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prowlersfish
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Re: prop spin

Post by prowlersfish »

hammerhead wrote: Sun Nov 08, 2020 3:23 pm f30 with 318's . will post video later
Did you post it on face book ?
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat :D
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Big D
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Re: prop spin

Post by Big D »

Tgornik wrote: Tue Nov 10, 2020 3:34 pm I have the same issue, and found it the same way... However, I also have a small crack in a freeze plug just outside the flywheel diameter. Water comes out, and sprays the clutch and i believe is the cause of the clutch dragging. (corrosion in the springs??)

I'm not exactly sure what to do about the clutch yet, but I know I have to pull the bell housing to fix the brass plug and was goign to address the clutch then.
I think you're referring to the damper plate. The clutch being referred to to here is inside the transmission. You will end up needing to replace the damper if you don't address the leak. Water in the bellhousing will also corrode everything in/around there including the ring gear/flywheel, starter, etc. If you put it off for too long, you may also have a hard time getting a new frost plug to seat and seal properly if the mating surface on the block gets so corroded from the water that the surface gets badly pitted.

If your prop is creeping, you may also have a transmission clutch issue. Like Paul said, while some movement isn't unusual, excessive creep is a sign there's a clutch problem.
She was a 1969 36 ft wooden beauty with big blue 440s that we'll miss forever.
And thanks to the gang, 2012 Trojan Boater Of The Year
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Tgornik
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Re: prop spin

Post by Tgornik »

Big D you are correct, I am referring to the damper plate. Now saying that, as its function is to air in reverse damping, I do hear it more than the starboard when going F to R.

Image

https://www.marinepartsexpress.com/Chry ... parfly.htm


Thanks for the other tips, all makes sense. I can see the crack in the center of the freeze plug and appears to be a fairly new brass plug. Boat is new to me in the middle of last season and previous owner did some work on this engine. Hoping to not have too much issue correcting.
"You're gonna need a bigger boat!"

1973 Trojan F31 Flybridge W/ Twin Chrysler LM 318s
rickalan35
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Re: prop spin

Post by rickalan35 »

Big D! Hope you're doing well.

Rick
Trojan 1994 370 Express, 502 Bluewaters
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Big D
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Re: prop spin

Post by Big D »

I'm all good Rick, really busy at this time of year though. I pop in almost every day still. You guys are doing a great job addressing all the inquiries. Still a great place for all things Trojan. I sure do miss my old gal.
She was a 1969 36 ft wooden beauty with big blue 440s that we'll miss forever.
And thanks to the gang, 2012 Trojan Boater Of The Year
hammerhead
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Re: prop spin

Post by hammerhead »

prowlersfish wrote: Tue Nov 10, 2020 5:56 pm
hammerhead wrote: Sun Nov 08, 2020 3:23 pm f30 with 318's . will post video later
Did you post it on face book ?
yes i did
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Tgornik
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Re: prop spin

Post by Tgornik »

Damper plate fixed the prop spin on my Port 318 with velvet drives. You can always start with an tranny oil change. Collect the old oil in a clear jar and inspect it after removal, (and settling..) If the oil change helps it could indicate a worn clutch plate.
"You're gonna need a bigger boat!"

1973 Trojan F31 Flybridge W/ Twin Chrysler LM 318s
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