Minor play on prop shaft

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Capt steve
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Minor play on prop shaft

Post by Capt steve » Fri Nov 17, 2017 4:53 pm

Hi guys
I’m running a couple of bigger boats for a tour company. I am a master captain that is just learning airboats. One of the boats is 25 feet and powered by a bbc 502 marine engine. There is a belt driven (what I beleive is a reduction gear) prop shaft. I noticed a tiny bit of side to side play in the prop shaft. I also feel a slight vibration that wasn’t there before. Checked our other boats and did not feel that play in the shaft. My first question would be can this lead to catastrophic failure and then what can it be and can I run it that way. The play in the shaft is very tiny but there

Thanks for your ideas
100 ton master captain
Professional airboat operator
I made enough money to buy Miami,
But I pi$$ed it away so fast

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skinnypockets
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Re: Minor play on prop shaft

Post by skinnypockets » Fri Nov 17, 2017 7:50 pm

Any detectable side play is a sign of bearing failure. It may run a while longer but why risk it. It will only get worse. The cost to replace the bearings now will be much less than waiting for it to go out completely and cause more damage, and leave you stranded with a boat load of tourist.
Just a matter of pay now or pay more later.
I'm basing my opinion on your description but I'm not there to look at it. I would recommend having a qualified mechanic check it out and if it is bearing failure have it repaired before the tourist season gets in full swing.

:rebel: :florida: :old_glory:
I'VE DONE SO MUCH WITH SO LITTLE FOR SO LONG, I CAN DO ANYTHING WITH NOTHING!

13.6 Alumitec, 350 Chevy, Rotator Gearbox and 6 Blade Warp Drive

Capt steve
Southern Airboat Member
Posts: 98
Joined: Mon Oct 23, 2017 10:36 pm
Location: Central Florida

Re: Minor play on prop shaft

Post by Capt steve » Fri Nov 17, 2017 9:12 pm

Thanks very much. I appreciate the quick response. I will have it checked right away.
I wish I could contribute more to the forum, but for the time being I have to be taker until l learn more. I will tell you I’m learning every day and love to drive these boats!!

Thanks again
100 ton master captain
Professional airboat operator
I made enough money to buy Miami,
But I pi$$ed it away so fast

Capt steve
Southern Airboat Member
Posts: 98
Joined: Mon Oct 23, 2017 10:36 pm
Location: Central Florida

Re: Minor play on prop shaft

Post by Capt steve » Fri Nov 17, 2017 9:29 pm

I’m sorry. One more question. Remember this isn’t DD so I assume we’re talking about bearings in the reduction unit not the main motor bearings. (Being that the prop isn’t attached to the crankshaft). Remember I’m still learning :|
100 ton master captain
Professional airboat operator
I made enough money to buy Miami,
But I pi$$ed it away so fast

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skinnypockets
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Re: Minor play on prop shaft

Post by skinnypockets » Fri Nov 17, 2017 10:36 pm

The fact that you suspected a problem shows that you are paying attention to your machinery and may well have avoided a serious problem. Well done! As with aircraft a good pilot always inspects his plane before a flight. It's the same with an airboat, always check your boat before each run.
As for your question, the shaft the prop is mounted on has two bearings and is separate from the shaft connected to the crankshaft. Most likely it is a belt drive and all the bearings and the belt should be replaced as preventative maintenance.
As for still learning,When we stop learning, our life here will be done!
:rebel: :florida: :old_glory:
I'VE DONE SO MUCH WITH SO LITTLE FOR SO LONG, I CAN DO ANYTHING WITH NOTHING!

13.6 Alumitec, 350 Chevy, Rotator Gearbox and 6 Blade Warp Drive

Capt steve
Southern Airboat Member
Posts: 98
Joined: Mon Oct 23, 2017 10:36 pm
Location: Central Florida

Re: Minor play on prop shaft

Post by Capt steve » Fri Nov 17, 2017 11:42 pm

Great info skinny. Thanks again!!
100 ton master captain
Professional airboat operator
I made enough money to buy Miami,
But I pi$$ed it away so fast

Capt steve
Southern Airboat Member
Posts: 98
Joined: Mon Oct 23, 2017 10:36 pm
Location: Central Florida

Re: Minor play on prop shaft

Post by Capt steve » Sat Nov 18, 2017 11:57 pm

Boat was put on trailer today and brought to mechanic. Thanks guys
100 ton master captain
Professional airboat operator
I made enough money to buy Miami,
But I pi$$ed it away so fast

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skinnypockets
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Re: Minor play on prop shaft

Post by skinnypockets » Mon Nov 20, 2017 7:09 am

Personally, I applaud Capt. Steve for asking for advice about something he's not sure about and what better place than the original southern airboat and I welcome him aboard!

WELCOME ABOARD CAPT. STEVE :salute:

:rebel: :florida: :old_glory:
I'VE DONE SO MUCH WITH SO LITTLE FOR SO LONG, I CAN DO ANYTHING WITH NOTHING!

13.6 Alumitec, 350 Chevy, Rotator Gearbox and 6 Blade Warp Drive

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Deano
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Re: Minor play on prop shaft

Post by Deano » Mon Nov 20, 2017 8:14 am

x 2 - As usual, SkinnyPockets in right again.

You are the right track brother, don't be discouraged over a hic-cup. Keep approaching it like you are and you will be fine.
Sometimes thick skin helps, though it's seldom needed; it's certainly not a prerequisite to hang out here.
The only dumb question(s), are the one(s) that don't get asked. Don't be bashful in that regard. :thumbleft:

It would simply be illogical to not use and abuse the wealth of knowledge that's available on this board.
Again . . . Welcome to SA.
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
- Carl Sagan

Capt steve
Southern Airboat Member
Posts: 98
Joined: Mon Oct 23, 2017 10:36 pm
Location: Central Florida

Re: Minor play on prop shaft

Post by Capt steve » Mon Nov 20, 2017 8:25 am

Thanks guys. Much appreciated and don’t worry. The skin is pretty thick :thumbleft:

I thank you for your help. As mentioned, at the mechanic now. Getting it done before the busy season. Definitely the right call. Will let you know what the mechanic says, if you guys are interested.

See you on the water
100 ton master captain
Professional airboat operator
I made enough money to buy Miami,
But I pi$$ed it away so fast

Capt steve
Southern Airboat Member
Posts: 98
Joined: Mon Oct 23, 2017 10:36 pm
Location: Central Florida

Re: Minor play on prop shaft

Post by Capt steve » Fri Nov 24, 2017 11:55 am

In this case a fairly reasonable fix. We had the same reduction gear on a motor we recently blew. The mechanic swapped units and will rebuild the old one. Had the boat back in four days.

Thanks for the info and advice. It is very much appreciated!!
100 ton master captain
Professional airboat operator
I made enough money to buy Miami,
But I pi$$ed it away so fast

KC5AKB
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Re: Minor play on prop shaft

Post by KC5AKB » Fri Nov 24, 2017 12:51 pm

Welcome to the Best Airboat Site on the net. Hello and welcome from Texas .
I have learned a ton of stuff from this site and made lifetime friends here.

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skinnypockets
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Re: Minor play on prop shaft

Post by skinnypockets » Fri Nov 24, 2017 9:58 pm

It's always good to hear when problems are detected before they become major issues. Too often we hear about problems that could have been prevented had the operator just paid attention to his, or her equipment.

It also sounds like you have a good reliable mechanic. If you don't mind sharing, it's okay to brag on someone, (on SA), that has done a good job for you and given good service.

Glad everything worked out well. :rebel: :florida: :old_glory:
I'VE DONE SO MUCH WITH SO LITTLE FOR SO LONG, I CAN DO ANYTHING WITH NOTHING!

13.6 Alumitec, 350 Chevy, Rotator Gearbox and 6 Blade Warp Drive

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