Broken Header Bolt
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Novice
Joined: Jul 2010
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Broken Header Bolt
Just finished replacing all new head gaskets and everything went smooth on a buddy of mine's '98 sportey screamin eagle. Turned the engine over once we got finished and she cranked right up. Had a little knocking but went away but noticed that the rear exhaust was spitting. Saw that the top nut was loose and went to tighten and next thing you know, the header bolts just snaps. Any ideas on the easiest vs best ways to fix. Thanks.
Road Warrior
Joined: Mar 2007
Posts: 1,912
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From: Cave Creek, AZ
I had one breake on my forks on a RK, went to the dealer and they gave me a new one, they were replaceable. For me it was easy enough to vise grip it and screw it out. Then I used red loctite for the new one and let it dry over night.
Elite HDF Member
Joined: Jul 2005
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From: Lockport Township, IL
If it is broken off flush so there is nothing to grab with a vice grip, You're going to have to drill it out. I'd get a reverse twist drill. If you are lucky, the bolt will spin out while drilling. If it doesn't, you'll need to use an easy out. Be careful though with the easy out. They are very hard and you do not want to bust one of them off in the bolt you are trying to remove.
Club Member
Joined: May 2007
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From: 40 miles Northeast of Indy..
Man that would suck... I was a machine repairman for 38 yrs, as stated above the easyout saved us a lot of work at times..
Before u start to drill make sure U use a center punch first to find and drill the bolt on center. Very important when using an easy out, keeps from drilling out the threads on the heads.
JW'ing,, did U use a torque wrench.?
U also said bolts, did both break or one.?
Before u start to drill make sure U use a center punch first to find and drill the bolt on center. Very important when using an easy out, keeps from drilling out the threads on the heads.
JW'ing,, did U use a torque wrench.?
U also said bolts, did both break or one.?
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Novice
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Yea and that was what was weird. The Torque wrench never released. I know the wrench is good because we used it on all of the head bolts when we were reinstalling the heads. OK. And thank you. Gonna give it a shot this weekend.
Club Member
Joined: May 2007
Posts: 145,895
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From: 40 miles Northeast of Indy..
Must have been in some kind of a bind somewhere to snap???
not sure what those bolts are make of, usually over torque just strip's them. but I have broken some in my time also..
anyway hope all is well soon.
not sure what those bolts are make of, usually over torque just strip's them. but I have broken some in my time also..
anyway hope all is well soon.
Grand HDF Member
Joined: Dec 2007
Posts: 4,999
Likes: 55
From: Bay Area
If you used the same torque wrench on the head bolts, it was way too big for exhaust studs thats probably why they broke, I think the torque on studs was like 12 or 20 fp max.
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OK. Great. Thank you. I am going to buy a new head bolt tomorrow as the Harley Dealership is closed today. Anyone know what size goes on a 1998 Sporty. Thanks. And if I get a reverse bit, would it need to be the same size or smaller. Thanks.
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Elite HDF Member
Joined: Jul 2005
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From: Lockport Township, IL
Definately smaller for the drill bit than the stud. you do not want to drill into the threads! You want the hole to be down the center of the stud. If you do not have a right angle drill, you may need to remove the head to drill it. I checked the manuals for my 03 and 04 bikes and the stud part number is 16715-83, but the manual does not give a description of the diameter of the studs. They look like 1/4" studs, so you're going to need a drill bit smaller than that to prevent destruction of the threads.
Grand HDF Member
Joined: Dec 2007
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From: Bay Area
I am sure they are 5/16" studs because I remember replacing the nuts on a friends bike that the dealer forgot to tighten, and we went to a local hardware store and got fine thread 5/16".
I looked up in out extractor set and it says to use a 3/16" drill bit for a 5/16" bolt, be sure to use a metal cutting fluid that will help a lot (old timer told me bacon grease or paint thinner will substitute in a pinch). Be sure to center punch and drill on center, cant over emphasize these two things enough. Good luck
I looked up in out extractor set and it says to use a 3/16" drill bit for a 5/16" bolt, be sure to use a metal cutting fluid that will help a lot (old timer told me bacon grease or paint thinner will substitute in a pinch). Be sure to center punch and drill on center, cant over emphasize these two things enough. Good luck