DavidO06

This weekend I decided to put in some new spark plugs, and when i was finishing up, i noticed a problem. When I was trying to screw down one of the "coil packs" on the passenger side, the screw just continued to turn freely, never getting tight. The other two went in just fine. I thought the screw was stripped and i went by my dealer this afternoon and picked up a new one. When i tried installing it, it felt a little tighter, but i am having the same problem. What should i do?

95_4X4Runner

If you know what the thread and pitch is, you can get a heli-coil kit, and rethread the hole. We so this at work often, it's not a big deal. But, if you're not comfortable doing it, I'd call a machine shop because those guys work with heli-coil inserts frequently.

Jay

Another great idea for a Jay's Tips ?

The difficulty of this operation always depends on the location of the stripped hole. In this case, piece of cake.

Back in my hot roding years, before installing a new aluminum intake manifold, I would heli-coil all the threaded holes. They are turely stronger than the original threads.

Jay

Mohamed

Interesting, can you guys explain what a heli-coli kit is? What is it's principal caz I know eventually I am going to need to use it.

All I got is a piece of ˟˟˟˟˟ craftsman extractor bit set.

Jay

HELI-COIL

Mohamed

Interesting, thanks Jay, it's looks like basically an expanding spring to me. When it does happen, and I drill for the Heli-coil, what do you normally vaccum out the shareds with? Or do you just completely remove the head?

Gadget

You should be able to drill and tap the hole in the cam cover without taking it off the engine. There are a couple of things you may want to do.

Figure out how deep the hole is and mark the drill bit with a piece of tape so you won't drill to deep and into the inside of the cam cover.

Start tapping the hole with the normal tap and then switch to what is called a bottom tap. Normal taps are tapered to get them started in the hole, but that hole is kind of shallow and the tapered tap will not get deep enough in the hole to put the threads down as far as you need for the Heli-Coil. When you follow up with a bottom tap it will cut threads all the way to the bottom of the hole so you can properly insert the Heli-Coil and then use the normal lenght bolt. If this hole went all the way to the other side they you could just use the regular tap alone and not be a problem.

Now the trick is to find a place that can get you the needed bottom tap. My guess is that hole is threaded for a 6mm bolt with a 1.0 or 1.25mm thread pitch. Most Heli-Coil kits come with the needed drill bit and tap and all you will need is to find a source for a bottom tap. I am sure a visit to one of the better machine shops in your area should be able to point you to the right vender for a bottom tap in the correct size.

Good luck and let us know how you made out.

Gadget

www.GadgetOnline.com

alanh

You can also order from places like J & L Industrial Supply. I've ordered stuff from them. I'm not sure what their minimum order is over the net (or if they have a minimum). There are a number of others as well, but I've only dealt with J&L, mostly because they have a store near where I used to work. I know they don't have a problem with retail sales and even though I don't order a whole lot, they send me big fat catalogs full of lots of goodies (if you're interested in metalworking). Of course, you'll have to know just what you're looking for since any big industrial supplier is going to have several different brands and types of taps.