Stripped bolt problem
Thread Starter
Drifting
Joined: Sep 2006
Posts: 3,379
Likes: 128
From: Stratford-upon-Avon
Stripped bolt problem
This should be so simple but having no success so far.
I was replacing hood release cable, and to route it through had to remove the top radiator rubber 'bumper' hold down on the RHS (mine is RHD). The bolt is 6mm Allen, and in removing it I noticed the hex was very worn, so replaced it with a nice new high quality bolt. I'd replaced the rad a few years ago, but kept the nice cad plated bolts there for originality's sake.
So I thought it sensible to replace the LHS bolt also, but it stripped out when I tried to remove. Since then I've cut slot in head and tried to get it moving using screwdriver as chisel, but it won't budge. The hole is too big for a T40 torx, but you can't get a T45 in there. Neither can you hammer in a 1/4" hex bit which is 6.35mm. I can't get one of my trusty Irwin bolt grips onto the head, as it sit's in a recess with cutout in lip of fender. For same reason it won't be possible to weld a nut onto the head as that lip gets in the way. Vise grips on the headd just slip. I have various screw extractors, but since the bolt won't budge when I try to persuade it with hammer and screwdriver, I can't see it moving. I'm going to try an impact driver with the original 6mm bit, and see if that shocks it into moving.
Any ideas what else I should try? I thought I knew all the stripped bolt tricks by now, but this one is defying me. Yes I could just leave it in, but it's going to haver to come out some day and now it's getting personal!
Thread Starter
Drifting
Joined: Sep 2006
Posts: 3,379
Likes: 128
From: Stratford-upon-Avon
Thanks I have tried lots of penetrating oil on earlier sessions, but getting any into the threads under that washer and bracket is probably why that was no help either.
Will try welding with precaution of disconnecting battery, brains and check I can get a good ground nearby. Maybe a small nut will fit and leave room for socket.
Will try welding with precaution of disconnecting battery, brains and check I can get a good ground nearby. Maybe a small nut will fit and leave room for socket.
Rennlist Member
Joined: Aug 2014
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From: Adirondack Mountains, New York
Just yesterday I used the cold chisel method on a torque converter housing bolt. I may have had better access than you. I hammered in it in straight to get it started then veered off to encourage it to turn. I sheared off chunks of it but it wouldn't twist. I had not yet fully stripped the Allen socket, so gave one last try - and it came out. The chisel probably broke the friction under the head, leaving only the threads.
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From: Oman
The impact driver is the first stop for you- just use a great big lump hammer for the percussion- that often works wonders. If that or other devious tricks fail next step is to remove the head of the bolt then you can get the securing bracket off. That should leave you short stub to play with that you can try some releasing fluid on. Beyond that you can also try to drill the bolt out
Drifting
Joined: May 2001
Posts: 2,150
Likes: 11
From: Taylors, S.C.
Drill the head off. Then if the shank is actually frozen in, step drill it up carefully (keeping it centered) to just under the thread size. Then pick the pieces out with a pic. Good luck with it.
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Rainman
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From: Nashville, TN
one more step to try before drilling is getting a spare XZN (cheesehead, triplesquare) bit and hammering it in there.
most of the time the splines will dig into the allen head well enough to crack it loose.
if you have a nice set of bits you dont want to sacrifice you can use a cheap set from auto store, about $8.
most of the time the splines will dig into the allen head well enough to crack it loose.
if you have a nice set of bits you dont want to sacrifice you can use a cheap set from auto store, about $8.
Thread Starter
Drifting
Joined: Sep 2006
Posts: 3,379
Likes: 128
From: Stratford-upon-Avon
Thanks all, lots of ideas there.
The impact driver with 6mm but didn’t work, but it doesn’t help that head isn’t exactly a precision fit now!
I’ve ordered cheap set of spline/triple square so I can try that before resorting to drill. Very puzzling - not as if it’s a highly torqued bolt. At least it’s not holding me up - just nice to fix correctly.
The impact driver with 6mm but didn’t work, but it doesn’t help that head isn’t exactly a precision fit now!
I’ve ordered cheap set of spline/triple square so I can try that before resorting to drill. Very puzzling - not as if it’s a highly torqued bolt. At least it’s not holding me up - just nice to fix correctly.
Chronic Tool Dropper
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From: Bend, Oregon
Think about where the other end of that bolt is. Is it accessible after removing the wheelhouse liner? Maybe you could get some penetrating fluid up into the threads from that end.
On my car, these and the crossbrace bolts appear to be zinc plated rather than cad. I'm not sure why, but it came up as I was cataloging fastener finishes in the engine bay for posteriority.
On my car, these and the crossbrace bolts appear to be zinc plated rather than cad. I'm not sure why, but it came up as I was cataloging fastener finishes in the engine bay for posteriority.
Thread Starter
Drifting
Joined: Sep 2006
Posts: 3,379
Likes: 128
From: Stratford-upon-Avon
Thats a good idea. I have MIG, any bolts I’m working on are red hot in an instant so would blow any corrosion away. But I couldn’t apply welder tip without dropping weld into head, so may as well try welding but on, or am I missing something obvious?
