# Stripped lower unit bolt...



## Tilly_Copano (Feb 12, 2017)

I was going to replace my water pump today and one of my bolts rounded out. It was pretty bad when I started but I made it worse. Any ideas on how to get it out? I have tried heat, pb blaster and using a bolt extractor. My only next thought is to weld another bolt on to the rounded one, could this mess up anything in the lower unit? You think jb welding another bolt on would work?


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## hipshot (Sep 29, 2018)

Assuming it's a hex-head bolt, there are stripped bolt sockets which can grip it and reverse it out. Are you any where near New Caney?


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## Guest (Oct 14, 2018)

You can weld a nut to it and should be fine with heat dissipation. You will want to heat the area around the bolt when trying to remove it to avoid beaking the bolt off in the midsection.


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## Tilly_Copano (Feb 12, 2017)

Im south of Dallas. I tried the stripped bolt sockets and it didn't work, slipping to much.


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## mro (Jan 24, 2018)

JB will not work.
Now if you read what I mean rather than what I've written you won't have any problems 

Is this a 10 mm head on the bolt?
If there is enough of the head still available sometimes you can literally file two flat spots opposite each other so you can use a pair of vice grips on the bolt head to work it loose.

Try not to damage the remaining head any more than necessary.

Still stuck?
If you were looking straight down the top of the bolt you can place a chisel on the outside edge of bolt head (about a 45 degree angle) and tap it so you have a small "dent or groove". For the next part you want a dull chisel to place in the groove at an angle that will unwind the bolt when you tap the chisel.
Normally all it takes is to move it an eighth of a turn and it may come out the rest of the way with the vice grips.

Last is drilling it out and use an extractor. I do not recommend this if you are not experienced. But if it needs to be done, you will need to use a sharp pointy steel punch. Make an indentation dead center of the bolt, then using a small drill bit (1/8") drill out the very center of the bolt. Now you can drill the bolt for the size of the extractor to be used.
Note: you don't want to drill all the way through the bolt if it can damage something below it. If you know the length of the bolt you can wrap some masking tape on the drill bit for a "depth gauge". Some where out in my garage I have a set of little steel donuts that have set screws which are made for drill bit use as depth gauges.


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## mro (Jan 24, 2018)

Tilly_Copano said:


> Im south of Dallas. I tried the stripped bolt sockets and it didn't work, slipping to much.


The snap-on ones work sometimes.


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## lemaymiami (Feb 9, 2007)

Most pros will simply drill it out -then insert a heli-coil followed with a new bolt...

This something that every marine mechanic should be skilled at.

Good luck post up your fix when it’s done.


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## Guest (Oct 14, 2018)

Weld a nut on it! You are gonna have to heat the piss out of it anyway to avoid breaking it.
I am a pro! Works a charm!


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## mro (Jan 24, 2018)

lemaymiami said:


> Most pros will simply drill it out -then insert a heli-coil followed with a new bolt...


If one of my mechanics were to jump right to installing a heli-coil w\o first trying to remove the bolt he/she would get their first warning, second would be letting them go find a job somewhere else. I've never had a steel bolt stuck in aluminum defeat me.


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## eightwt (May 11, 2017)

I'm a forester not a mechanic, but I've watched loggers repair equipment in Bum F___ Egypt for 42 years and they used Boatbrains method. It works.


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## Tilly_Copano (Feb 12, 2017)

It's a 14mm bolt. I have it soaking in pb right now and I plan to try the chisel next. If that doesn't work I'll weld the bolt. I don't think it's seized I think the bolt was just about stripped when I started on it and I just went at it to much. All the other came lose.


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## Guest (Oct 14, 2018)

Tilly_Copano said:


> It's a 14mm bolt. I have it soaking in pb right now and I plan to try the chisel next. If that doesn't work I'll weld the bolt. I don't think it's seized I think the bolt was just about stripped when I started on it and I just went at it to much. All the other came lose.


Skip the chisel, weld the nut!


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## mro (Jan 24, 2018)

If you have your engine manual it may have the fastener torque specifications. If not then the manufacturers web site should have them. That size bolt I'm guessing around +/- 12 ft pounds. Very common mistake for new or limited experience mechanics is to over tighten fasteners until they can't get one back off without going through what you are now, then half would go the other way and not tighten stuff enough. If you don't have a torque wrench some auto part store (at least out here on the left coast) loan or rent tools. Most mechanics don't use a torque wrench for something like your doing now but they have developed a "feel" over time. I had about 20 years experience when I got into a hobby of restoring old Yamaha 1101 cc motorcycles. Their engines are mostly aluminum so I got into the habit of using a torque wrench on all the fasteners for awhile until I was comfortable tightening em up.

1979 XS1100 Special


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## TheAdamsProject (Oct 29, 2007)

Its stainless, grab it like hell with vice grips and twist the head off. Then undo the other 3 bolts and drop the lower unit. You now have more bolt to grab a hold of and shoot PB blaster onto the threads rather than the head and washer


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## Guest (Oct 15, 2018)

nativejax said:


> Its stainless, grab it light hell with vice grips and twist the head off. Then undo the other 3 bolts and drop the lower unit. You now have more bolt to grab a hold of and shoot PB blaster onto the threads rather than the head and washer


This works, but only if it breaks in the right spot!


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## texasag07 (Nov 11, 2014)

If your proficient with a angle grinder or cutoff wheel on an angle grinder you can cut/grind down the head and then do what native jax said.


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## Rick hambric (Jun 24, 2017)

Boatbrains said:


> You can weld a nut to it and should be fine with heat dissipation. You will want to heat the area around the bolt when trying to remove it to avoid beaking the bolt off in the midsection.


Bingo!!! If you brought it to my shop that’s what I’d do!


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## State fish rob (Jan 25, 2017)

G


Boatbrains said:


> View attachment 45252
> Weld a nut on it! You are gonna have to heat the piss out of it anyway to avoid breaking it.
> I am a pro! Works a charm!


go boy !!!! Nothing better ,congrats


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## lemaymiami (Feb 9, 2007)

You’re right- most of what I’m familiar with are snapped off or sheared off bolts where you have little or nothing to weld onto....


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## Guest (Oct 15, 2018)

lemaymiami said:


> You’re right- most of what I’m familiar with are snapped off or sheared off bolts where you have little or nothing to weld onto....


The pic I posted, that bolt was beoke off about 3/16 in the hole.
Extended tungsten on mig torch, layed washer over opening, built weld up washer then welded nut to washer. No easy task, but no heli coils, no cross drilled bolts, just clean factory holes!


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