Removing stuck, snapped bolt.

[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.

 

[LiamR]

Try welding a nut to the backside of it (place nut on top and fill with weld) and extract from the back? Hopefully the heat from the welder will help with removal... might have to use thin wall socket for access.

Those just look like cast strengthening ribs, you could cut just enough away very carefully for better access.

Fingers crossed!

 

[atomman]

Can you get a small 90 degree air drill in there ? or in the past I've had to use really long gun drill to get to a snapped bolt

 

[Ian]

Not possible because the size of the head of the chuck prevents you from getting a straight line. And because its recessed even a long drill bit won't work.

 

[Rob Gaskin]

Ian, are you sure it moved or do you think it was the bolt shearing?

Liam's idea was good but I can't help thinking that this may need drastic action if you can't scrap the motor. Could your cut around the bolt to allow the bits to be dismantled and then weld the casting back together once you have removed the now exposed bolt?

 

[atomman]

Can yo get to the other side ? drill it out from the back ? then tap the hole next size up or just use a nut and bolt instead

maybe use a 90 degree small die grinder and put the drill in the collet not as big as a chuck then

use a slitting disc on a grinder or a hack saw and cut the bolt between the flanges so yo can get them apart , then drill bolt out , retap and then TiG up the face and machine it back to get a good seal ?

 

[Albrecht]

A good candidate for Spark Erosion, I would think.

 

[IbanezDan51]

A good candidate for Spark Erosion, I would think.

If you cant get at it with a drill you've got little to no chance at getting an spark erosion machine in there.

How come the leg hasn't come apart with all the heads removed? Or has it? And that's the other pictures? How much material is left sticking out?

 

[Albrecht]

If you cant get at it with a drill you've got little to no chance at getting an spark erosion machine in there.

In another life, I was a toolmaker. We often had to spark erode difficult sections of injection moulds. My boss was a genius at it. I remember him making a telescopic electrode for a particular job which had stumped everyone else.

I'm wondering how much of the remaining bolt needs to come out before the halves would come apart? It's certainly not all of it.

 

[Ian]

Ian, are you sure it moved or do you think it was the bolt shearing?

Pretty sure it moved before shearing.

Could your cut around the bolt to allow the bits to be dismantled and then weld the casting back together once you have removed the now exposed bolt?

Not really any way to cut it, the bottom engine cover is preventing access from anything other than perhaps a screwdriver.

A good candidate for Spark Erosion, I would think.

Bit advanced for this, not worth the expense.

How come the leg hasn't come apart with all the heads removed? Or has it? And that's the other pictures? How much material is left sticking out?

Leg is not held on by the block, its bolted to the bottom engine housing, which is sandwiched between the leg and engine block.

Can yo get to the other side ? drill it out from the back ? then tap the hole next size up or just use a nut and bolt instead

Nope, you can see the top side in photo 4, if it had happened on either of the bolts on the other side this would have been an easy option.

se a slitting disc on a grinder or a hack saw and cut the bolt between the flanges so yo can get them apart , then drill bolt out , retap and then TiG up the face and machine it back to get a good seal ?

Problem is access, no room to get any cutting eqiupment in there. I don't even think a small dremel cutting disc could access the space.

I'm wondering how much of the remaining bolt needs to come out before the halves would come apart? It's certainly not all of it.

I'd say there is still 15mm in there.

Try welding a nut to the backside of it (place nut on top and fill with weld) and extract from the back? Hopefully the heat from the welder will help with removal... might have to use thin wall socket for access.

This may work, although I guess the bolt could shear again further up. Still worth a try if I can't get anything else to work.

 

[IbanezDan51]

if im looking correctly can you get an angle grinder in with a thin cutting disc between the sandwich plate and engine block? Cut through the bolt to separate them?

 

[Mr Tenno]

Crazy idea but is there any way it could be drilled out from the other side?

 

[Ian]

if im looking correctly can you get an angle grinder in with a thin cutting disc between the sandwich plate and engine block? Cut through the bolt to separate them?

No chance, theres only 15-20mm of room between the sealing faces of the two parts and the outer cover.

No grinder is fitting down there.

Crazy idea but is there any way it could be drilled out from the other side?

Not a crazy idea, but not one that can be implemented, look at the 4th photo down in my first post, you can see the scribe pointing to something, that is the other side, its covered by the engine block.

 

[Huw]

You might get a Dremmel cutting disk in there Ian, they are only 1 to 2 mm in width. Or a pad saw?

 

[Alphabettispaghetti]

I’d cut a deep notch in it with a 30 mm cutting disc then use a flat head screwdriver that’ll take a spanner on it

 

[Ian]

Managed to fit a 20mm dremel cutting disc in there on a flexible shaft. Cut in far enough to let the bolt break.

 

[LiamR]

Wahoooo

Nice one buddy. Glad you got there in the end.

 

[Ian]

Its a start, still got a lot to do before it can run again. Got to remove 4 snapped bolts from around the engine, clean out all the blocked coolant passages, clean and paint it all, replace half the bolts and 4 gaskets and put it back together. Plenty to keep me amused.

 

[Rob Gaskin]

Its a start, still got a lot to do before it can run again. Got to remove 4 snapped bolts from around the engine, clean out all the blocked coolant passages, clean and paint it all, replace half the bolts and 4 gaskets and put it back together. Plenty to keep me amused.

Well done.

How much is that engine worth Ian and is it special?