Hey all, my wife just got a '99 Cherokee and the bolt for the bracket closest to the throttle body was broken. I attempted to extract it but failed. My question is can it be drilled out and retapped to a bigger size? If it can how far can I go down without drilling into the intake itself? Or am I screwed and have to buy another intake?

 

The manifold is pretty thin, but if you break thru, it can always be sealed with some Locktite sealer, then use a stud instead of a bolt. If the bolt is broken off flush and not recessed, you can mig-weld a nut on it and the heat of the welder should break it loose and allow you to screw it out.

 

Breaking through and putting a stud in sounds like a good idea. Any idea on how to keep the metal shavings from getting into the intake? Welding it doesn't sound like a bad idea but when I drilled it to try and put an extractor in it kinda buggered up the thread so I can't screw anything back out. Yea, I botched it.

 

Pack the drill flutes with grease and drill slowly, wiping it off and replacing it several times will keep most of the chips out. A few tiny ones aren't going to hurt the engine at all and will probably melt in the converter. If it's right near the throttle body, you may get them out with a shop vacuum by taking it off. You can grease-pack the tap as well.

 

You can just drill it to the size you need to tap it out to put a new bolt or stud in it . It doesn't hold a lot so it doesn't need a bunch of treads . A 1/4 to a 1/2 inch will be enough .

 

That's a great idea, thanks man! Using grease never occurred to me. And I will take off the throttle body and see what I can suck out of it.

 

thanks, I appreciate that! Do you know off the top of your head how thick the intake is in that spot?

 

Just off the top of my head, a cast manifold should have like 1/4" wall thickness. Now who knows how deep they drilled it or how high the bolt boss is? OH....WAIT! Check the length of the other bolt and that should give you an idea of how deep you can drill. A bottoming tap needs just a slightly deeper hole than the threads.

 

If you drill all the way thru, you don't need a bottoming tap. Your choice.

 

I'm starting to like the drill all the way through idea. Is red loctite going to be enough if I put a stud in, or do I need an epoxy once its threaded in?

 

I'd just go with a teflon pipe sealant.

 

If the stud has a section that's not completed thread, that itself should seal it, If not, Locktite it so it stays in. A tiny bit of vacuum leakage will be compensated for by the IAC.

 

Thank you all. I can't get to the hardware store until this coming weekend to grab a stud, I'll let you know how it goes. Wish me luck!

 

Probably not necessary, but if you are worried about metal chips getting sucked into the motor you can blow air through the tailpipe. One of the exhaust valves will be open. The chips would hopefully want to go out rather than in. A vacuum exhaust or air mattress inflator ought to do it.Then do the grease on the tap trick, and maybe a shop vac nozzle next to the tap.

Good luck.

 

I wanted to give a big thanks for the help. I got it drilled and tapped for the stud and got the stud in. I didn't even have to go all the way through the manifold. I used red loctite gel so I'm going to wait until tomorrow it put the nut on to give it time to set up.