Stubborn bolt removal tricks?

[Pub911]

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.

[davidpm]

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?

[bljones]

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.

[WanderingStar]

Penetrating oil and time first. Kroil is the best I ever used. Let it soak in for several days. Then use mechanical means.

[Pub911]

Kroil has been on these things for weeks.

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

What's PB blaster?

[bljones]

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.

[bljones]

PB Blaster beats Kroil every time, in my experience. i haven't used anything eles to remove stuck bolts in the last 5 years.

Blaster Product Testimonials

[Izzy1414]

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

[BlueWaterMD]

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.

[Izzy1414]

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