How can I remove this stuck snapped bolt?

[EF Ian]

I can't think of anyway to remove this bolt, perhaps someone smarter than me has a solution?

Its on old outboard used around saltwater, the bolts were all well seized but with, heat, penetrating oil, shocks from a hammer and a lot of back and fort I managed to get the others out, however one snapped after only 5mm of movement.

The other side

I would normally drill it out, but its in a recessed slot, there is not straight access to the bolt in order to drill straight down its centre.

The scribe is pointing at where it insert into the block.

How much is still inside:

Wish it could have happened at the other side, I could have drilled down from the top.

 

[Dave..]

Have you tried the spray freeze? I think it helps crack the bolt so you could take it out in bits.
Screwfix do it or google it.

 

[Antoin]

Does that part split now that all bolts are out and the bolt is broke off the last ?

Could you get a nut welded onto the remaining bit and unscrew? The heat might free it up.

 

[amcm1]

Would a 90° drill and an easy out do it?

 

[EF Ian]

Have you tried the spray freeze? I think it helps crack the bolt so you could take it out in bits.
Screwfix do it or google it.

Don't see that working, it might shock a bolt with a head enough that it breaks free, but its not going to freeze a broken one cold enough to let you break it up.

Does that part split now that all bolts are out and the bolt is broke off the last ?

No, still being held, its possible both parts might have some thread but I can't get a clear enough view or feel to be sure. Either way the powerhead is still attached solid by that one bolt, I can only lift it about 1mm at the other side with a pry bar.

I had a notion of putting a lot of force on it with a big pry bar to snap the stuck bolt, but that likely to warp thins too much.

Could you get a nut welded onto the remaining bit and unscrew? The heat might free it up.

You might be able to weld a think enough bar onto it, but theres really nothing protruding to enable a nut to welded on. Even if you managed to weld a bar on you would have to weld it at an angle due to it being in the recess.

Would a 90° drill and an easy out do it?

No, I don't think so, the head on a 90' drill is too big to let you get close enough to drill straight.

Its stuck so solid an easy out won't work, tried one already.

 

[Antoin]

You don't really need anything protruding.
I've had success with setting a nut over a broken stud that was flush with the surface, setting the mig gun right over it and filling it with weld. The more filling the more heat going in which is good for this situation. Your enemy is whether or not you can get a nut sitting nice and also being able to get the mig gun at the correct angle.

Judging by the other bolts there isn't any thread holding the flange on so I reckon it is free but just seized on likely (the motor that is).

Edit; that being said don't be forcing it lol

Throw a load of diesel around it and let it soak as well. Much better than any penetrative fluid I've found.

 

[EF Ian]

There is a small hole near where the scribe is in the photo, it can fit a standard spray bottle straw down it. I could fill that up with a liquid and let it soak down. I'l try some diesel.

Judging by the other bolts there isn't any thread holding the flange on so I reckon it is free but just seized on likely (the motor that is).

Well, the motor is loose apart from the one bolt holding it, so if the lower leg section has no thread then it should be possible to just pull the bolt up with the block. However those other bolts that you can see on the other side of the motor are out of the block, but still stuck on the leg unit, they will turn but do not move down, I guess if they were in a threaded section they would have to move down or they would just not move at all.

 

[Antoin]

Can't really follow what you mean Ian.
Can't get it in my minds eye cos I'm not familiar those boat engines!

Those two bolts shown in pic two can't be removed despite being undone is that what you are saying? Are they different to the bolt shown in pic 5 or how die it come out?

 

[EF Ian]

Those two bolts shown in pic two can't be removed despite being undone is that what you are saying? Are they different to the bolt shown in pic 5?

Exactly. They are removed from the block, but stuck in the leg. I tried turning and leveraging down while turning and tapping down with a hammer. Not too worried about them as they will be easier to remove once the block is out the way. But is might show if the lower section is threaded or not. I guess it can't be actually, as the thread between the block and the leg where it bolts up to would have to match up perfectly then, so I guess it must be smooth, the lack of thread on the bolts also indicate this.

The bolts shown in pic 2 and 5 are the same.

 

[Antoin]

In that case I can't see how the bolt is still holding the block to the leg given that the head of the bolt is gone.

I assume the leg houses the propellor driveshaft? Could there be more to undo relating to the driveshaft that is preventing the leg from coming away from the block. Seized splines possibly.
Have you nr of the motor to search for an exploded diagram of the entire assembly?

 

[EF Ian]

I assume the leg houses the propellor driveshaft? Could there be more to undo relating to the driveshaft that is preventing the leg from coming away from the block. Seized splines possibly.

The leg won't come away, all I am removing is the block. The leg is still attached to the bottom part of the cover, this is sandwiched between the leg and the block.

Can you guess why its coming apart?

And that ladies and gentlemen is why salt water is not an ideal coolant for an engine.

 

[Antoin]

That's a lot or crud !

@EF Ian are there studs going down the way.... through block and screwing into the leg? See pics 4 and 6 in your first post. Look to be 13mm studs going down into the leg.

 

[EF Ian]

That's a lot or crud !

Sure is. Thats why she was overheating. lol

@EF Ian are there studs going down the way.... through block and screwing into the leg? See pics 4 and 6 in your first post. Look to be 13mm studs going down into the leg.

They go down through the cover and into the leg, but they are separate to the block. All the bolts holding the block down come from underneath.

If you are seeing the threaded holes in the block thats where the bolts coming from underneath thread into.

 

[Antoin]

If you unscrew those studs holding the cover to the leg it may let the leg away and give you access to that broken stud.

 

[EF Ian]

Not a bad idea, means a lot of other things have to come apart in order to drop the leg, but its better than loosing the motor. Some bolts will be hard to access with anything, but I reckon a crow foot should work.

 

[Nicky]

@EF Ian What material is the part of the block with the broken bolt stuck in it? Cast steel?

 

[Dexter mcf]

Cut everything away around about with a grinder

 

[NI_Volvo_Nut]

The top part of the flange won't be threaded, its likely corrosion on the bolt is making the housing stuck. DO NOT USE WD40 on the stud as this expands the corrosion and makes the bolt tighter. My advise would be to head around the stud and try to get leverage as close to the bolt as possible and try to level it up

 

[dddrrift]

that's going to be a drill job I think

 

[EF Ian]

@EF Ian What material is the part of the block with the broken bolt stuck in it? Cast steel?

All alloy I believe

Cut everything away around about with a grinder

Which part?

My advise would be to head around the stud and try to get leverage as close to the bolt as possible and try to level it up

Can't get any leverage near it. Its still very solid.

that's going to be a drill job I think

Can't get a drill straight inline with the centre so that will not work.

 

[dddrrift]

you could drill it, but its going to involve stripping that lower cover off, if there are no bolts left holding it on then it must be stuck just.

 

[EF Ian]

I don't see how removing the lower cover could help. Its sandwiched between the block and leg. However it does look like I can remove the leg unit which although tricky with the block still in place does at least look to be possible. If I can do this then I would have proper access to drill straight down the centre of the bolt.

 

[Daviddunlop83]

Both parts won’t be threaded.

I can’t see what else would be holding it on apart from corrosion unless it has to slide up rather than straight off?

Take it to an engineering shop. Amazing what they can get out

 

[stevieturbo]

Also not following what you're showing.

The bolt has no head ? therefore there is nothing larger than the hole, that cannot pass through the hole ? So it has to be simply corrosion.

Heat is the first normal course of action, a decent mapp gass type torch would be a starting point. Although from a corrosion point of view...maybe some decent acid might eat it a little to free things up.

 

[dddrrift]

yes, that's what I mean, your going have to strip that lower casing off one way or another to get at that bolt. There shouldn't be anything holding it on if all the other bolts are out and the head if off the broken one. start by stripping the hanging bracket off and get a rubber lump hammer. Joys of corrosion.