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True Wind
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Alternator Bracket Broke

I was in the process of upgrading my lack luster standard 55amp alternator to a 120amp with external regulator. When I took the alternator off, this what I found. Very disappointing considering there is only 330hours on the motor. It looks like some cheap cast iron. I think I'll take it by a machine shop and see if I have a heart attack with the cost. I don't think I'll have an option as a 120amp alternator will put a serious amount of force on the bracket.

​Anyone ever had one of these machined?
 

2003 Catalina 36

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Catboat Willy
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Dave;
 Regrets that this happened to you. I certainly be interested in your following up with the group and seeing how you make out at the machine shop. $$
 With today's CNC machines, it may not be as expensive as originally thought.
 Good luck with this.
 Bill

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LeslieTroyer
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TrueWind

be sure and let them know welding the ears on is fine rather than machining from single block.  Much cheaper.  

I hate to break it to you but you are going to be hard pressed to get a 3/8 belt to run a 120A alternator   

 

True Wind
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Captain Les
I'm a few boat lengths in front of you. I've already upgraded to J10 pulleys. Just need a firm footing to hang that dang aletnator.
David :)

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KevinLenard
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Hm.  That looks a lot like aluminum.  A number of the parts attached to the cast iron engine block are aluminum, such as the mounting piece between the coolant pump and the engine.  Sometimes a weld is even stronger than the original metal with iron/steel, not sure about aluminum. K.

True Wind
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I dropped it off today at a machine shop today. Waiting to get a quote on a new fabricated bracket made out of steel. Not sure I want to put that much faith in that old bracket with a new 120amp alternator.
David 

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LeslieTroyer
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Dave if I'm not doing anything else at the time I'd be glad to lend a hand/supervise.  

 

True Wind
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Captain Les
​Today is travel Tuesday. Buy your tickets to South Carolina and save a few bucks. When you get here, I'll buy you a hot bag of boiled peanuts.
 
David

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LeslieTroyer
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Think I'll pass.   I miss-read your post thinking you were one of the other C36's ahead of me on the dock.    Oooops

 

Maine Sail
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Failures of these brackets is not at all uncommon, we've seen about 6 or 7 and all were broken before a better alternator was installed.. Westerbeke used to make these out of machined steel then switched to cheap cast then machined aluminum. They essentially have zero flex before failure so if the alternator foot is even off by a few thousands of an inch they can snap. Best to have a machine shop duplicate it out of steel....

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Haro
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I replaced my bracket recently with stock alternator.
I am curious if a stronger bracket is fabricated will it break the engine mount instead?

True Wind
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Just got my new steel bracket back from the machine shop. Going to prep and paint and install my new 120amp alternator with external regulator. The machine shop kept the dimensions in their computer if anyone wants to replace that useless aluminum bracket.
 

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Haro
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That is a nice job. Can you tell us what was the final cost and who to contact for this version?
Haro

True Wind
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The cost of the machined alternator bracket was $350.00. If anybody is really interested in getting one, let me know and I will provide the machine shop info.

David

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