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Discussion Starter #1
I have 6 out and 2 to go....

The two remaining are (round headed) allen-head bolts. They're holding the damper plate to the flywheel, so I suspect they've been torqued pretty good and may have loctite on them too. The other 6 came out pretty easily with steady, centered pressure. But these two rounded the allen recepticle and now the wrench just goes round and round. :(

They're in close quarters, so a brute-force big-ol-vicegrip approach isn't (and didn't) work because the grip of the vicegrips bumps against things. The bolts themselves, are small, about a 3/4" long, 5/32" shaft diameter and about a 3/8" round head with a 4MM allen fitting in the center.

So, what are the tricks? Heat? mini-vicegrips? chisel? file a face on the head to create a surface for a cresent wrench? Easyouts?

I really don't want to end up having to drill them out at the risk of then having to replace the flywheel when I screw up the drill alignment and damage the receiving threads. I'm on my belly as I do this work, reaching below the the level of the cabin sole into the bilge.
 

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I suspect that if you put your vicegrip in at an angle to clear the handle you can only grab the bolt head with a corner of the vicegrip jaw.

Vicegrips are cheap. Would it work to grind the corner of the vicegrip jaw so there is a flat spot to grab with?
 

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ouch. Here's my approach, in order of preference:
1. if the flywheel is not threaded, CAREFULLY grind off the head of the offending allen bolt, remove the flywheel, then clamp down on the stub of the bolt with a pair of vicegrips and remove with a little torch heat.

2. use an impact driver and hammer in a size larger torx or 12 point allen socket. Use lots of PB Blaster to help break the bond.

3. If you have a welder, clean the bolt and weld a nut to the stripped head. use a regular socket on the nut to remove the stripped bolt.
 

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Discussion Starter #5
Kroil has been on these things for weeks.

I like the Torx driver idea....will try. other ideas welcome.

What's PB blaster?
 

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Does the bolt head look like the one on the left or the one on the right in this pic?


if it is the one on the right, use two pairs of vice grips- one pair clamps tightly to the head of the bolt, sticking straight out, and the second pair clamps to the first pair at a right angle. Use the second pair to provide leverage to turn the pair clamped to the bolt head., along with copious amounts of PB Blaster.
 

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..........huh?..
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Pub,

They do make an "easy out" of sorts that grabs the outside of the bolt head. Probably several brands, I know Craftsman has them. If you can't get something to grab then I kinda like bl's idea of grinding off the head, leaving you more to work with after removing the flywheel. Go carefully because if you break the darned bolt you WILL be drilling (and Probably tapping). Good luck, my Knuckles are bleeding in sympathy for you!

Doug
 

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Weld a nut to the top, so you can then get a good sized wrench on it. Have had to do this a few time myself, and it works great. Od course if you don't have a welder, I would try some of the other ideas first.
 

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Just a precautionary note if the welder option is viable. Ground as close as you can to your work, being careful not to ground on the other side of moving parts such as shafts and bearings. It is also a good idea to disconnect all power to protect your electronics.

Doug
 

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Aspiring to be a Mexican
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Many years as a mechanic on aircooled engines has taught me that 3 things get tough bolts out. Heat, impact (not torque), and juice. By juice I mean Wurth Rost Off, Kroil or PB Blaster. PB may be my favorite. If those fail I weld a nut on and impact it off. Welding and impact are much easier in my shop than they are on a boat.
 

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Aspiring to be a Mexican
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My favorite obviously is a 1/2" drive air impact that does 600 ft lbs in reverse. That's difficult on a boat so probably a hammer driven impact driver will get the job done unless the heads are too stripped out, then you're down to a chisel if you can't get a nut migged on there. I've had to use the chisel on Porsche CV joint bolts lots of times and on flywheel bolts a couple of times. I start pounding the chisel straight into the axis of the bolt to build a bit of a shelf to hit on later. After I've formed something to hit with the chisel I'll start moving it so that I'm striking parallel to the axis of the bolt in the direction that will begin to unscrew the bolt. As long as you have access to the side of the bolt head and enough room to swing a hammer this will usually work. The last resort would be to drill the head off of the offending bolt(s) to get the flywheel out of the way. I've only needed to drill out 2 bolts in the last several years.
 

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You might try to cool them down. There are sprays available for cooling threads. They are not oily. They freeze the metal which shrinks the metal and the adhasive content between two is broken, during application a few strokes with a hammer is also helpful. Then you might use a wrench which might hold a loosened screw.
 

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Discussion Starter #16
They're out!!! Due in large amount to all of your helpful advice. The trick that did the trick - hammering a slightly larger than appropriate torx socket into the rounded allen-hole. A little leverage and I was on my way.

Thanks, all!

(and SWW914 - I know those CV bolts well, my other "sailboat" is a 30yr old 911SC Targa -funny!)
 

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Mark on Camper 58
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If you have space, I often resort to a high speed die grinder. It is a 20,000 rpm pneumatic or electric tool that spins a carbide inserted tool cutter. (McMaster-Carr) The tools come in different shapes by the box and fit in a 1/4 inch tool holder. With these you can cut almost anything quickly and accurately. The bits are called carbide burrs (about page 2589)

I like the welded nut plan too if you can make the arrangements.
 
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