Sconnie Nation Heli-Coil Care packagemidget,Here is everything you need to repair the stripped thread. Some instructions for you, and others who have never installed a Heli-coil:
1) Read the kit instructions . . . . .
2) Use a lubricant for drilling and tapping. Tap Magic for Aluminum works well, as does CRC 5-56, or WD-40 in a pinch. DO NOT DRILL OR TAP DRY.
3) Use the ground v-block to support the drill bit at 90 degrees to the surface. This is essential for an effective repair.
4) Support the tap with the v-block as well, same idea, 90 degrees to the surface.
5) The tap in the kit is a general purpose plug tap with 3 tapered threads. You will not be able to "bottom" tap using it. If you need to bottom tap, you get to buy a special
Heli-coil bottom tap or buy another std Heli-coil plug tap and carefully grind it into a bottom tap. Do not anneal the tap while grinding it down. Deburr it after grinding.
6) While tapping, reverse the tap to "break the chips", often. Disregard at your own peril . . . . .
7) The inserts supplied are the std length. The insert should be as long as possible for the best thread engagement. Inserts are made in various lengths, and for this
situation, you want thread diameter x 2, so 7/16ths diameter requires 7/8ths length. Unsurprisingly, 7/8ths length inserts are available . . . .
8] BEFORE inserting the repair coil, measure the depth of the hole. On a bottom tapped hole, the insert length will be hole shoulder depth - 1/8th inch. Top of the
insert "tail" needs to be 1/32nd to 1/16th below the block surface. Insert coils can be CAREFULLY shortened with a cutoff wheel if need necessary. Carefully deburr.
9) Breaking off and removing the "drive tang" in a blind hole is a pain in the a$$. And just for added fun, the stainless steel inserts are NOT magnetic . . . . . .
10) Just in case the insert is too long and projects above the surface, you MIGHT get lucky and be able to "unwind" it out. If not, just grab it with a needle nose vise-grip
and pull it out. Start over with a new insert, shortened a bit more . . . .
11) Yeah, the plastic insert installation tools are crappy and weak. You need to be careful. I don't know if the old steel installation tools are still available. I just make
a steel installation tool out of a grade 5 SHCS or bolt if I need one. (SHCS = socket head cap screw, allen bolt) A hack saw and a file will work on a grade 5 bolt.
Anybody else who has installed a lot of Heli-Coils, feel free to add your tips.
Fordboy