Bronco Forum - Full Size Ford Bronco Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
My 93 Bronco had a bad exhaust leak when i bought it, so i decided to install the summit shortys which turned out to be pacesetters but anyway, i didnt have any trouble on the driver side, but i broke two bolts off in the head on the pass side. I tried a bolt extractor and broke it off in the bolt and it was Matco brand that i use at work. So its looking like helicoil is my only option. Anybody had this problem, whats the size for the helicoil?? Thanks for any help.
 

·
Registered
Joined
·
580 Posts
The bolt size and thread pitch is your helicoil size. You have to get that stuff out of there first. I would reccomend pulling the head first. There is no way you can do that tedious of a job with the head on the motor. I would look into a process that slips my mind right now, but , ask a machine shop what to do in order to get it out. The helicoil would be my last resort.

The process requires an electrode that goes in and burns the bolt out w/o damaging the threads. usually runs about $40.00 if you can find someone to do it. There is a place here in Tulsa that does it . The place is Dean's Grinding 918-838- 0756. You might give them a call and see what it is called so you can find a place close to you that does it.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #3
The bolt size and thread pitch is your helicoil size. You have to get that stuff out of there first. I would reccomend pulling the head first. There is no way you can do that tedious of a job with the head on the motor. I would look into a process that slips my mind right now, but , ask a machine shop what to do in order to get it out. The helicoil would be my last resort.

The process requires an electrode that goes in and burns the bolt out w/o damaging the threads. usually runs about $40.00 if you can find someone to do it. There is a place here in Tulsa that does it . The place is Dean's Grinding 918-838- 0756. You might give them a call and see what it is called so you can find a place close to you that does it.
Well luckily the two that broke are behind the shocks and with inner fender out i can get to them with a drill, so im gonna try a heli coil.
 

·
Registered
Joined
·
4,914 Posts
I think the process of the Bruno2 is referring to is called "Electric Discharge Machining" (EDM)
I've had good success using Helicoils. Make sure you use the Helicoil recommended tap drill. Depending on how deep the hole is, you might have to use two inserts to get sufficient thread engagement length, just install one insert all the way to the bottom of the hole (after using the Helicoil tap, of course), then install another insert on top of it and make sure you break off the tang on the second one.
Be cautious that the tap starts square to the hole.
I also have used Vaseline as a tap lubricant, it catches the chips well.
Go slowly when you tap, turn the tap no more than a 1/4 turn before backing the tap to break the chip, then forward another 1/4 turn, back a little (you'll feel the chip break when you back off. Pull the tap and clear the chips every full turn or so.
If the tap gets hard to turn, it's probably because you are not square to the hole, don't break the tap off in the hole. It also could be that you are to the end of the hole, or that the hole is full of chips at the bottom of the hole. Blast some WD-40 (for example) into the hole to clear the chips.

Good Luck
 
1 - 4 of 4 Posts
Top