The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - what size drill bit and tap for 3/8 heli-coil

mikep · 09-14-2002, 10:49 PM

All you do with the tap sleeve is drill abd tap the old bolt hole out to whatever the OD thread of the sleave is . For a 3/8 you'd go to 1/2-13 or 7/16-16 depending on what sleeve you had. The you screw it in the newly tapped hole. Thats it . Make sure you accurately center punch the middle of the bolt before you drill it out. Not rocket science here. A little bilt one way or the other wont really affect something like an exhaust bolt. I assume its still in the truck.

09-14-2002, 10:49 PM	#9
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	All you do with the tap sleeve is drill abd tap the old bolt hole out to whatever the OD thread of the sleave is . For a 3/8 you'd go to 1/2-13 or 7/16-16 depending on what sleeve you had. The you screw it in the newly tapped hole. Thats it . Make sure you accurately center punch the middle of the bolt before you drill it out. Not rocket science here. A little bilt one way or the other wont really affect something like an exhaust bolt. I assume its still in the truck. __________________ No truck :-(