Helicoil in Transom OK?

Horigan

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Jun 12, 2016
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While replacing the anode on the transom of my OMC Cobra outdrive on my signature boat (same as Volvo Penta SX), I managed to strip the threads in the transom for the anode due to corroded threads. I plan to install regular helicoils for both bolt holes using loctite to hold in the helicoils in and triple guard grease for the bolt threads. Do I need to do anything else for this repair, such as trying to find stainless helicoils?
 

hemi rt

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Most helicoils are stainless steel, What type of hull are you working on - Fiberglass, aluminum or steel? A helicoils is going to need at least 3/16" of material to hold, you don't need anything to hold the helicoil in place as the outside threads are an interference fit to the threads that you tap in before putting the helicoil in. Unless you are going into steel the helicoil probably won't hold; if going into aluminum if it is 3/16" thick or more you will be OK.Anything like thin aluminum or fiberglass and a helicoil won't hold. An other way would be to tap the thread out to the next size up.
 

Bondo

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Ayuh,.... Heli-coils Are ssteel,... 'n don't use loc-tite, as the anode needs a solid electrical bond to the housin',....
 

Horigan

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Jun 12, 2016
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Thanks on both inputs. This is going in to the aluminum transom mount on the outdrive. Sorry for the confusion. This is my first helicoil experience, hence the questions. Wish me luck.
 
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hemi rt

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Just follow the instructions that came with the helicoil and you should be good to go.
 

Horigan

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No Title

It's raining outside, but this should explain where the threads are stripped on the lower transom mount.
 

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Horigan

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Jun 12, 2016
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Well, then I'd have to drill out the new anode every year to handle the bigger bolt. I installed the inserts for both bolts and it went pretty quickly. Thanks for all the inputs/help.
 
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