2004 DF115 Holder Corrosion Mitigation Plan

[Tidnish]

As you can see from the pics, I believe I have the Holder Corrosion. As far as I can tell, there isn’t a hole thru the aluminum yet and some moderate poking suggests it’s not too thin. I didn’t try and drive a sharp object thru it with a hammer but it seems solid. The plug is very corroded. I know I need to address this and have done some research on the best method. Here is my plan, let me know where I can improve it!

I have the replacement Plug and first want to try and remove the existing Plug and replace it. Soaking with PB Blaster or similar may help. The hex in the plug is shot so I need to grab the plug somehow. Maybe vice grips on the outside, cut a screwdriver slot with a Dremel, or? I can heat the surrounding aluminum with a small torch and try to wiggle the plug out.
My concern is if the surrounding alum is weak, and I’m too aggressive, I may break the Holder so I plan on being cautions. If this doesn’t work, on to Plan B.

This would be drilling the center of the plug out to the root of the threads, or close to it. I can determine this from the replacement Plug thread. Once this is done, I can then cut slots thru the remaining plug material being careful to not damage threads or seal surface, then using a punch, try and collapse the remaining Plug material inward. This may allow its removal, or at least may allow it to be rotated out.

If this doesn’t work, Plan C is to get the Plug out and get the hole welded up.
Plan D is to replace the Holder.

As our boating season is short, I’m going to leave this alone (other than applying PB Blaster occasionally) until the fall and keep fingers crossed!

Thanks


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[Solarman]

I think the sooner you address the plug, the better your chances of removal will be. I would heat the plug itself, and avoid the surrounding metals as much as possible, using the pb lube. Cutting a slot for a large screw driver seems best, unless you can get a similar to-r-x bit to bite good.

The longer you wait, the weaker the surrounding metals will be.

Good luck, post back when possible of how it goes.

[Flashback]

You could try an Eze out tool if your going to drill center of plug out,I've had success with this tool on other projects

[nelbur]

Plan B will work, as that was my approach. Use a half inch drill until it bottoms out in the hex hole. Then drill through with a 3/16" bit and go back to the 1/2" to finish drilling through. Knock the remainder loose using a large nail set and hammer.

[briscoe]

Why not try the 10mm allen wrench?

Looking at the pic it appears that the rust is on the metal plug and not the adjacent aluminum housings. Use the PB blaster and a 10mm end allen socket on a break over bar. Tighten a little then loosen a little. Yes, I said tighten. Back and forth, back and forth. It may need a little heat, but try with the allen head wrench first. Unless you think the housing has given it up, which it does not look so to me.

[Tidnish]

Thanks everyone for the input. I'm going to let this ride for the summer and thy the removal in August or Sept. Its a gamble but, well, one I'm going to take.

Yes, the plug is rusty and the surrounding alum seems solid. The HEX is stripped so need to use another method of gripping the plug. Thats why i'm considering vice grips or cutting a screwdriver slot. Hopefully it will back out. If not, on to Plan B

[briscoe]

Slotting for screwdriver, not

I have an 07 and removed mine after I heard about the first issues, probably in 2010. It was pretty difficult to remove. Too bad you don't live closer to my house (Houston metropolis). We could tack weld the allen wrench and remove it. You got this. All I can say is that it's tougher to remove than you can imagine. It took some torque using a break over bar. Even force in and out will remove the plug.