Broken lag bolt removal?

[sledge]

Not much left above the stringer. Tried a drill out but broke the drill bit. I'm thinking a hole saw is the only thing left but open to ideas.

[Ratickle]

Need a little more info and a pic maybe? Where is it, how deep, etc.

[sledge]

It was an engine mount lag bolt. Probably 2.5-3" long. What else can I tell you? There's not much to take a picture of. It looks like.....a bolt with the head broken off. :D

[boatman574]

Did you Try a Left Hand Drill Bit??? Bolt Extractor??

[DAREDEVIL]

Engine mount lag bolt ??????? mhhh never seen that,,the ones i used and always seen are trubolted.
If its smaller then 1/2 inch,,,take a 1/2 inch drillbit and drill it completeley tru and later stick a tru bolt in there with a washer and locknut !!!!
Don't use a cheap bit.

[Griff]

You should be able to drill into it and use an "easy out"
I've never had a broken bolt that couldn't be drilled and come out that way as long as you have good access to it.

[Trim'd Up]

Engine mount lag bolt ??????? mhhh never seen that,,the ones i used and always seen are trubolted.
If its smaller then 1/2 inch,,,take a 1/2 inch drillbit and drill it completeley tru and later stick a tru bolt in there with a washer and locknut !!!!
Don't use a cheap bit.
There are quite a few boats that lag the engine mounts. They are lagged through the top of the stringer so you can't through bolt them without new mounts. My baja used to be like that.

An easy out should work just fine but your gonna have to drill into the bolt. They aren't usually hardened bolt so it should drill pretty easy.

[imco offshore]

leave the bolt alone, if the head is off , remove the mount modify it either lengthen it or shorten it , so a new hole can be drilled about a half inch away.obviously the stringer is sound, if you broke the head off. or use differant mounts like dd said and thru bolt them, good luck

[sledge]

No thru bolt mounts, and highly unlikely that a factory Volvo engine mount will get modified for relocation.

It's a stainless bolt and it's not giving up easily. My buddy tried a bolt extractor but broke the bit inside the bolt.

No thoughts on using a hole saw to extract and then dowel/resin/glass the hole?

[Ratickle]

No thru bolt mounts, and highly unlikely that a factory Volvo engine mount will get modified for relocation.

It's a stainless bolt and it's not giving up easily. My buddy tried a bolt extractor but broke the bit inside the bolt.

No thoughts on using a hole saw to extract and then dowel/resin/glass the hole?

My thought is, I wouldn't. Unless you modify the mount as George said, you'll want to go directly back in the same location. Stainless is a b-t-h to drill......:ack2:

[Knot 4 Me]

No thru bolt mounts, and highly unlikely that a factory Volvo engine mount will get modified for relocation.

It's a stainless bolt and it's not giving up easily. My buddy tried a bolt extractor but broke the bit inside the bolt.

No thoughts on using a hole saw to extract and then dowel/resin/glass the hole?Do you have enough surface area to just rotate the mount one direction or the other and just drill a new hole to lag into? The mounts can be installed crooked as long as the verticle stud remains in roughly the same location. Mine from the factory were mounted as crooked as a dog's hind leg on the stringer block.

[imco offshore]

Do you have enough surface area to just rotate the mount one direction or the other and just drill a new hole to lag into? The mounts can be installed crooked as long as the verticle stud remains in roughly the same location. Mine from the factory were mounted as crooked as a dog's hind leg on the stringer block.

that was my thinking also. i haven,t seen a mount that couldn.t be swivelled to drill a new hole,

[Audiofn]

I would try and weld a bolt to it and then twist it out.

[PayCheck]

Cut the thing off flush with the stringer and put an L bracket in there:sifone:

[Chris]

Hole saw is a bad idea. Previous post is a good one- saddle mounts.

[sledge]

Thanks guys. FWIW, this is for a buddy's cruiser. Twisting the mount is IMHO the best/easiest, but dude's a little retentive so we'll see. Doesn't help that the whole reason we pulled the lag bolts was because the mount nuts would not budge. Yet he things everything will just drop back in without having to adjust them....you can only lead a horse so far...

Paycheck, nice drawings! :D But the friggin' stringers on this pig are 8 inches wide. Just too much material and effort.

The weld thing works easy when it's a steel bolt...in a nice safe non-flammable area. :D Even if it was worth trying to get a TIG in there, not sure I'd want to weld on a bolt in wood and fiberglass? Plus, it's stainless with a steel core (see broken drill bit above) :D.

[Buoy]

Cut the thing off flush with the stringer and put an L bracket in there:sifone:

That's exactly what I did on my Baja.

[DAREDEVIL]

Thanks guys. FWIW, this is for a buddy's cruiser. Twisting the mount is IMHO the best/easiest, but dude's a little retentive so we'll see. Doesn't help that the whole reason we pulled the lag bolts was because the mount nuts would not budge. Yet he things everything will just drop back in without having to adjust them....you can only lead a horse so far...

Paycheck, nice drawings! :D But the friggin' stringers on this pig are 8 inches wide. Just too much material and effort.

The weld thing works easy when it's a steel bolt...in a nice safe non-flammable area. :D Even if it was worth trying to get a TIG in there, not sure I'd want to weld on a bolt in wood and fiberglass? Plus, it's stainless with a steel core (see broken drill bit above) :D.

OK,,,,,NOOOOOOWWW,,,wait a minute here and back up.......DO U REALLY WANT TO GET IT OUT ,,OR ARE U JUST TRYING TO FIND EXCUSES WHY U DON'T GET IT OUT ??????

:rofl::sifone::icon_bs:

[Griff]

With an 8" wide stringer, rotate the mount and be done with it. That or tell your buddy to fix it himself or pay somebody.

[old377guy]

Cut the thing off flush with the stringer and put an L bracket in there:sifone:

my 302 Formula had those cheesy lag bolted mounts. I had L-brackets made similar to what paycheck indicated; really the only way to go short of true offshore mounts. good luck

[Turbojack]

Get a left hand drill bit. Since a friend told me about these I have never missed getting a bolt out.

[Throttle Fever]

Weld a good size washer to the top or what is left of it. Then weld a nut to the washer and back it out. Let some heat transfer and the heat will break it loose from the stringer. Do not get it hot to the point of anything starting on fire. Done it a dozen times and it works great. Pete

[MOBILEMERCMAN]

With an 8" wide stringer, rotate the mount and be done with it. That or tell your buddy to fix it himself or pay somebody.

You have already talked about it longer than it took to pull the motor.

I am with Griff. Besides the mounts have a slot on one side anyway. You probably won't need to rotate it much at all.

[sledge]

You have already talked about it longer than it took to pull the motor.

:sifone:

Actually, you guys have talked about it :biggrinjester: but I'm sure there's plenty of people that appreciate the good ideas.

Twist the mount is the winner on this job. Luckily the Volvo mount has a slot on one end so it got turned around to use the one good hole (:rofl:) and the other got relocated to the side just a bit. Took a while to get the motor done but it's all together and bolted in; the drive should go back on this afternoon if weather and meetings don't interfere.

Thanks again everyone for chiming in!

[BradH]

I'd slap a little paint on the broken drill bit to limit the rust stains.

[phragle]

the volvo guy probably went at it with a cheap drill bit with a fast drill and no lube and work hardened it. with stainless you need a good bit, slow speed and lots of cutting fluid. I'm suprised he broke the bit instead of dulling the tip

[sledge]

the volvo guy

:sifone:
That would be my buddy and me. We don't need no stinkin' dealer service meng. That's what you guys are for.

Decent bit, spray lube...the problem was I let him use the center punch and run the drill. I looked at the center punch...it was dull (no wonder the bit didn't take a set at first). Then with the drill set crooked, he let it wobble and that's all she wrote. The second bit did dull so we ended the effort. We sprayed some corrosion block on it and it's sitting on a horizontal surface under the engine mount so it's all good.

Everything went back together real easy after that and just doing break in these days.

[sy goldberg]

You should have had STECZ breathe on it.:26::26:

[Geronimo36]

Snap-On high-speed Cobalt drill bits, best bits I ever bought!

[Comanche3Six]

Dremel with a cut-off wheel (small profile) Cut a groove in the center of the sheared bolt, screwdriver bit on a ratchet.
Good Luck
Ed