Large broken bolts

Sat Feb 05, 2011 10:37 pm

We have large broken bolts in the bell housing. How do you get them out? Thay have been there for about 42 years that I know of.
Last edited by Mark Antal on Sat Feb 05, 2011 10:41 pm, edited 1 time in total.

Re: Large broken bolts

Sat Feb 05, 2011 10:40 pm

Have you tried welding a nut onto the stub and turning it out after soaking with a penetrating oil?

Re: Large broken bolts

Sat Feb 05, 2011 10:48 pm

No, the bolts are broken off flush. Is the bell housing cast iron? I have seen someone heat up a broken exhaust stud in a car head (cast iron) with a cutting torch. They got it red and blew out the stud when pressing the oxygen lever without damaging the head. They still had to clean the threads with a tap or thread chaser.

Re: Large broken bolts

Sat Feb 05, 2011 11:13 pm

Are you sure they are broken bolts and not corks?

Re: Large broken bolts

Sun Feb 06, 2011 7:13 am

Jim Becker wrote:Are you sure they are broken bolts and not corks?

:lol: Yes, I recall the Saturday when I had everything assembled to tackle the broken bolts. It was a lot easier than I expected when I discovered that the factory corked the mounting holes.

Re: Large broken bolts

Sun Feb 06, 2011 8:33 am

Or dirt dobber nest :D

Re: Large broken bolts

Sun Feb 06, 2011 8:52 am

If someone broke that big of bolt off the bell housing it would possibly have a big hole in it. There might be other damage.

Re: Large broken bolts

Sun Feb 06, 2011 9:23 am

they make a miracle welding rod for bolts broke off like that.a friend of mind who is a welder had some and got 4 head bolts out for me.i have bin around welding all my life and have never seen anything like it . (dad was a pipeline welder) i will try to find out more about it.

Re: Large broken bolts

Sun Feb 06, 2011 9:44 am

I agree with Jim. Very good chance they are corks.

Re: Large broken bolts

Sun Feb 06, 2011 10:35 am

If they are still the original corks, I suggest getting a 5/8 tap to run through the holes after removing them. The threads tend to become rusty n those holes with the corks in them.

Re: Large broken bolts

Sun Feb 06, 2011 11:17 am

The problem is maybe someone used a bolt that was too long and its sticking out on the inside and its rusted really bad on the inside so it broke when someone tried to remove it. The only cure now I would do is to remove the bell housing and look from the inside to make sure whats going on. Then soak it with kroil on the inside and drill it for a big easyout or like mentioned about weld a nut to it and again soak it really good and maybe try some heat around the hole to expand the castiron around the hole so the broken boltcan be extracted. The bolt on my seat post was rusted so bad i need to drill it out and retap it. I cut the hex head off with the torch(surgical cut is what i call it) without damaging any parts and ground it flush, then i center punched the hole on the brocken bolt surface and started drilling it. I stepped drilled it until it was at the tap size. We retapped it and it was done. On the threaded holes in that housing i plan on installing the setscrews with lots of anti seeze when there not used. Or install shorter bolts with anti seeze to prevent problems in the future. Sometimes the orginal thing just isn't what it was once designed for lasting for so many years. Down the road the older orginal design just doesn't cut it. Unless you have a museum piece. I want functionality over orginality. Bill

Just food for thought, we all have been there and done this too even i have without thinking about it;
We need to think when we do things too, were all frugal at times and we seem to think a longer bolt will work too. But we forget about the extra length on the inside thats going to rust up and jam the bolt from comming out down the road. So sometimes longer isn't better or ok. We need to stop and rethink it before we just put it together because it fits and will work at the time. Even though its been done by the previous owner we still need to rethink it and do it right. Down the road its "us" that will take it apart. I would also suggest a good moly anti seeze too. I also think about when we assemble these why not put a small dab of silicone around the bolt hole on the bracket were mounting to keep the water from getting in there? Then if were using the correct length bolt we should be ok.

BTW; Being a welder i put a put tac's of the MIG welder in the center of the broken bolt. I will first put tac's and try to build the weld straight up. Then i have a good bond to the stud. Then i fit a nut with a big enough hole to fit over my tac's and weld it up solid. Now heat around the hole staying away from the bolt just heat the castiron. Most of the time i heat half the hole 180 degrees rather than 360 degrees. I notice with 360 degrees of heat it all expands too much. With just 180 degrees of heat half the hole will expand and it will break free. Rather than the 360 degrees of heat expanding the whole area. But sometimes this works and sometimes it doesn't thats when we redrill and tap.

Re: Large broken bolts

Sun Feb 06, 2011 11:31 am

If it should be a long bolt as Bill mentioned, the easiest way to remove it might be to try turning it further in and let it fall into the bottom of the torque tube. it won't hurt anything there.

Re: Large broken bolts

Sun Feb 06, 2011 10:43 pm

It very well may be cork. I never checked.
Thank you for all the good in put.

Re: Large broken bolts

Sun Feb 06, 2011 10:59 pm

You won't be the only one pleasantly suprised if it is cork. I was.