shaft wobble

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Heefus
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Post by Heefus »

Well, she started tapping again :roll:

At about 1900 rpms she makes a racket, but will stop hitting at anything over that. The shaft is only 1" OD, so it will self center once the rotational speed picks up.

So I am left with a delimma:

I know that I can safely run her, on plane, without the shaft hitting anything. I also know that I can just putt, on the starboard engine, and only use the port engine for docking. I spoke with the PO, he lets me use his lift for repairs, and he said I am welcome to bring her over anytime to move the strut and align it properly.

I believe I will pull her again, as I plan on fishing into December, but it will have to wait until late July/early August as I will be traveling quite a bit this month.

I am also tossing around the idea of re-powering to new 5.7 Mercs, possibly fuel injected, and rebuilding the starboard Vdrive while I am at it. I guess I just really need to decide if this is going to be a 5 year boat, or a 10 year boat. If she is gonna be a 5 year, then everything stays, as-is, and I just maintain as necessary. A 10 year plan gets new engines and drives.

Dunno :lol:
'76 F28
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prowlersfish
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Post by prowlersfish »

You said:
"At about 1900 rpms she makes a racket, but will stop hitting at anything over that. The shaft is only 1" OD, so it will self center once the rotational speed picks up."

That real makes no sense to me , Is it only making the noise in gear ? if so I would try aligning the engine / trans to the shaft
Last edited by prowlersfish on Fri Jul 08, 2011 5:52 pm, edited 1 time in total.
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Heefus
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Post by Heefus »

prowlersfish wrote:"At about 1900 rpms she makes a racket, but will stop hitting at anything over that. The shaft is only 1" OD, so it will self center once the rotational speed picks up."

That real makes no sense to me , Is it only making the noise in gear ? if so I would try aligning the engine / trans to the shaft
Since the shaft is narrow, any wobble will even out as rotation speed is increased.

The skeg is not aligned properly with the thru-hull so I will have to move it. I adjusted the engine position, as best as I could, to compensate for the skeg.
'76 F28
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prowlersfish
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Post by prowlersfish »

Is this the same noise you thought has a engine noise ? What is the shaft hitting ?
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat :D
Heefus
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Post by Heefus »

prowlersfish wrote:Is this the same noise you thought has a engine noise ? What is the shaft hitting ?
The same engine, but I figured out that the actual engine noise was a leaky exhaust gasket.

The shaft is hitting the bronze thru hull plate at the underside of the hull.
'76 F28
larryeddington
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Post by larryeddington »

FYI just in case you want to try it, I did and the drive saver biscut between transmission and shaft will not work on Paragon V-drives. I is too big and hits the bottom of the transmission. Apparently it only works only on straight through drives. I do not know of any alternative that works.

Just for information in case you wanted to try it as part of your fix. I have an F-28 as well.
Larry Eddington
1984 F-36 Tri Cabin "The Phoenix II"
1978 F-28 "The Phoenix"
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9.5' Dink
pk
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Post by pk »

I´m not sure, but what is a "skeg"??? :?
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larryeddington
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Post by larryeddington »

He is refering to the strut that supports the shaft and contains the cutlass bearing.
Larry Eddington
1984 F-36 Tri Cabin "The Phoenix II"
1978 F-28 "The Phoenix"
Fish Master 2350 Bay Boat
9.5' Dink
pk
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Post by pk »

Ooooo....!! I see! Thanks.
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Heefus
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Post by Heefus »

Update:

Took the offending shaft to the local machine shop this week. It is .003 out of line, right up by the flange end. I could see it move while on the lathe.

I am going to go ahead and have a new one made. It doesn't seem like much, mathematically, but seeing it wobble on the lathe is a whole other matter :shock:
'76 F28
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