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Son of a.......

Grumpy Bear

Grumpy Bear

Regular Contributor
Put the powerhead back on my rebuilt 1974 Merc 500 50hp. But I hadn't torqued it to spec yet as I had to figure out how to do that with the limited torque wrench I had. Tonight, I go to torque and everything is going well until the 3rd stud. It snapped. Ffffff me.... I hadn't even gotten to the required 15 fp. So, off comes the powerhead with all the ruined gaskets that will have to be replaced and surfaces re-cleaned (used Permatex aviation to ensure a good seal) and new gaskets ordered along with a new stud -- probably from eBay. I wonder if I should replace all the studs to mitigate this happening again? What do you think? Meantime, I have to get the remaining stud out of the block without screwing something up further. This makes me nervous. So much work to restore this motor.... Any good advice getting this stud out without doing more damage? Other good words? Thanks all...

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If it snapped off flush with the surface you have a real problem. (If not, try working it back and forth with Vice Grips.)

The usual removal method is to center punch it and drill most of it out, then using an Easy Out (or collapsing the shell of the stud inward with a punch). If you use an Easy Out, be damn careful not to snap it off or....

Jeff

PS: I'd toss out that damn torque wrench and use the mechanic's method instead. To wit: Tighten the nuts in a cross wise pattern, get them nice and 'tight', then add a wrenching flat or two. (A hex bolt has 6 flats.) Then retighten after the motor has warmed up for you'll be surprised at how loose they'll get.
 
fastjeff said:
If it snapped off flush with the surface you have a real problem. (If not, try working it back and forth with Vice Grips.)

The usual removal method is to center punch it and drill most of it out, then using an Easy Out (or collapsing the shell of the stud inward with a punch). If you use an Easy Out, be damn careful not to snap it off or....

Jeff

PS: I'd toss out that damn torque wrench and use the mechanic's method instead. To wit: Tighten the nuts in a cross wise pattern, get them nice and 'tight', then add a wrenching flat or two. (A hex bolt has 6 flats.) Then retighten after the motor has warmed up for you'll be surprised at how loose they'll get.
Click to expand...

Then I have a real problem. It didn't just snap off flush, it's just inside the hole where it's seated. I assume I will have to take this to a machine shop to drill and back this thing out? No way to re-tap it, of course. I swear, to get this far rebuilding this thing and this happen.......
 
racerone said:
Take it to a machine shop.
Click to expand...

I'm wondering.... There's only maybe a quarter to a half inch of stud in that hole. If I drilled into it (without going all the way through it!) and used a reverse bit or easy-out with lots of heat on the aluminum block (since the stud is steel and will expand slower), I wonder if I could carefully back that out? Worth a try or not worth the risk??
 
BACKED THAT BROKEN-OFF STUD OUT with a fluted bit! Now waiting for the replacement I got on eBay for $5. Gaskets not ripped (though coated with Permatex Aviation Form-A-Gasket) so I hope I can re-use them.
 
fastjeff said:
PS: I'd toss out that damn torque wrench and use the mechanic's method instead. To wit: Tighten the nuts in a cross wise pattern, get them nice and 'tight', then add a wrenching flat or two. (A hex bolt has 6 flats.) Then retighten after the motor has warmed up for you'll be surprised at how loose they'll get.
Click to expand...

Just so I understand, tighten till they're good and tight but not so tight that they can't be turned anymore, do the cross wise pattern (which I do), then go back again with the cross wise pattern and turn each nut one or two more "flats" (i.e., 1/6 to 1/3 turn). Is that what you mean?
 
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