Unable to tighten Inbord prop shaft Castle Nut sufficently to install cotter pin

alldodge

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The 1 3/4 prop shaft goes through the transmission, hub goes over the shaft, then the castle nut is installed. The nut is hand tightened and the cotter pin hole can be seen. Put the wrench on it and it cannot be further tightened enough to make it to the next opening on the castle nut.

This is the same boat which we just replaced the 454 Horizon last summer. The 3 inch key is starting to show signs of wear.

Any suggestions?
Wonder if there are shim washers that are about .010 thick.
 

NHGuy

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Re: Unable to tighten Inbord prop shaft Castle Nut sufficently to install cotter pin

Maybe get another key? If the keyway is ok and the key is wearing that's maybe why the nut is stopping in a wrong spot. Would a fresh key make the nut stop where you want it to?
 

alldodge

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Re: Unable to tighten Inbord prop shaft Castle Nut sufficently to install cotter pin

Maybe get another key? If the keyway is ok and the key is wearing that's maybe why the nut is stopping in a wrong spot. Would a fresh key make the nut stop where you want it to?

Thanks for the response. We thought of the key but believe it shouldn't be an issue. We used the process of who the prop is installed. We slide the hub on without the key and mark the spot. Then install the key and the hub and it came to the same mark. Then install the nut. The bronze nut shows signs of wear on the threads but not a lot. May just need another nut but would like to rule out other possibilities.
 

alldodge

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Re: Unable to tighten Inbord prop shaft Castle Nut sufficently to install cotter pin

Here is a link to a site full of prop hardware. http://www.*************/content-tags/tag_id-64/anchor_bushing.html Maybe your answer is in there.


Or maybe your nut to thread interface is too worn. I don't speak inboard...c'mon who knows straight drives?

Thanks, but iboats messed the link up with ****
What's the name (dot) com ?

I wasn't into inboards either until a buddy started having problems a few years back and things changed. Same thing happened with out drives, now I can't say that either. :D
 

Fastatv

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Re: Unable to tighten Inbord prop shaft Castle Nut sufficently to install cotter pin

The 1 3/4 prop shaft goes through the transmission, hub goes over the shaft, then the castle nut is installed. The nut is hand tightened and the cotter pin hole can be seen. Put the wrench on it and it cannot be further tightened enough to make it to the next opening on the castle nut.

This is the same boat which we just replaced the 454 Horizon last summer. The 3 inch key is starting to show signs of wear.

Any suggestions?
Wonder if there are shim washers that are about .010 thick.

Hi AllDodge. Wish I could help in some way here. I am curious...something changed if it fit prior to removal. Is this shaft in too far, is there a burr on the hub, a burr on the castle nut, was a washer or shim left out upon reassembly, are the shaft threads damaged? I will follow your thread, curious to see solution, and learn. Rick
 

Walt T

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Re: Unable to tighten Inbord prop shaft Castle Nut sufficently to install cotter pin

I've simply modified the nuts.
 

alldodge

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Re: Unable to tighten Inbord prop shaft Castle Nut sufficently to install cotter pin

Hi AllDodge. Wish I could help in some way here. I am curious...something changed if it fit prior to removal. Is this shaft in too far, is there a burr on the hub, a burr on the castle nut, was a washer or shim left out upon reassembly, are the shaft threads damaged? I will follow your thread, curious to see solution, and learn. Rick

The motor was changed out but everything went back in as before. We pulled the hub off again to check all surfaces and everything looks fine. The nut does show some wear but nothing drastic. There were no washers or shims used.

I've simply modified the nuts.

Hey Walt, we have been talking about that, but wanted to make sure from pros before we did start grinding or other such. Buddy got a hold of Marine dot something in Washington state. Took several pictures of everything and sent them up. After review he could find nothing other then the threads looked worn. He ordered another nut and the guy says if it does the same thing "Grind on the back of the nut", go figure. So the company got $45 for the nut plus shipping. Think we could have found the same nut for $25 but, not my money.

If we need to grind on the new nut, I'm thinking about going to McMaster Carr and get a washer. They make some stainless steal washers which are .010 thick which should work for $6.

Once we know something I'll update
 

NHGuy

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Re: Unable to tighten Inbord prop shaft Castle Nut sufficently to install cotter pin

I think the iboats software stopped the reference to another parts source, so I tried PM'ing you. If it fails chase me down. There's got to be some logical way to solve your issue without overspending. Good luck.

ps. As far as that washer, I'd only use the same material as original. So only do a stainless washer if there's stainless on there already. Or to put it the other way, if it was built with bronze stuff don't use a stainless washer where it could wear the parts it touches.
 
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alldodge

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Re: Unable to tighten Inbord prop shaft Castle Nut sufficently to install cotter pin

I think the iboats software stopped the reference to another parts source, so I tried PM'ing you. If it fails chase me down. There's got to be some logical way to solve your issue without overspending. Good luck.

ps. As far as that washer, I'd only use the same material as original. So only do a stainless washer if there's stainless on there already. Or to put it the other way, if it was built with bronze stuff don't use a stainless washer where it could wear the parts it touches.

You PM wound up with the same issue. Only way I know around it is to paste it, then remove the "." and make them spaces. Then another can just add them back. Thanks for trying
 
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