Matt16

1990 4Runner 22RE. I broke off a bolt that goes through the oil pump and the timing cover and into the block. I drilled it out and got the closest size of Helicoil. I am having a hard time tapping into the iron block. Also the provided tap is too short.

Any advice?

fastkevman

First off, I hope that you are using taping fluid, if not GET some, I use Tapmatic but, Tap Magic is also good, at the very least use a lot of spray lubricant.

Second, you can order standard, long, and extra-long taps from many different vendors, such as, MSC, Mcmaster-Carr, etc.

Good Luck!

P.S. I mainly work with stainless steel, hard to tap, so I use coated drill bits and taps, the above vendors sell them also.

Matt16

I didn't have cutting oil so I was using a liberal amount of WD40. The hole has already been drilled, took a while but its there. Any tips on starting the taping process, I can't get it to bite.

Matt16

help...

Jay351

We had to put 2 heli-coils in Jason block, that was a royal pain!

You really need to push into it to tap the threads.

fastkevman

I have VERY, VERY carefully tapped the tap a couple times with a hammer in some rare instances in the past but, make sure your hole is the right diameter first, that may be the problem.

Also, you can get away with using spray lube but, a dedicated tapping fluid is best and if you are using a wrench instead of a tap handle be real careful that the tap stays straight, especially when starting out.

Jay351

Hardest part was getting the first few threads so the tool wouldnt move and fall back out.

CJM

WD40 isnt lube, you in the very least need some kinda oil.

Matt16

I've tried hammering the tap into the block a bit, and it keeps slipping out. I did some reading and wikipedia suggested using a tapered tap to cut into steal or iron. Next issue is finding the right tap that is long enough.

refried

Why is the tap too short? are you trying to go thru the cover and pump with the tap? pull everything off and get down to the block then try to tap it.

Matt16

Oil pump, and T cover are both still on, I aam hoping I can leave them on.

toy283

You're not likely to find the correct tap except from Heli-Coil. The tap is not a standard tap. It is a larger diameter to account for the thickness of the Heli-Coil insert.

Matt16

I called around and, as Dave just said, Heli-Coil uses a unique sizing scheme, and it is unlikely that I can find something to work. So my options are as follows:
*have a special tap made up ($80, 2 weeks wait)
*tap a larger hole, use a wider bolt torqued to factory spec
*leave the bolt out for the time being and in two weeks deal with it when the special tap arrives


Any other options out there? Keep in mind this bolt goes through theoil pump, through the timing cover and into the block.

Matt

Green93

The thing that messed me up was that I was trying to work around the headers. I messed around for quite awhile before just removing the headers so I could have good access to the hole. After that they both went in within a couple minutes. Moral of the story? If you are trying to work around something...bite the bullet and remove it. Or you will fight with it for an hour like I did and in the end, end up taking it off anyways.

It wasn't a total loss though...Jay351 was quite entertained with my performance.

Jason

Green93

Did you buy a Heli coil kit? That's what I did, on the outside of the package it has the tap size. They just pulled it off the shelf for me. Go to a store that specializes in fasteners.

Also, If this bolt goes through the oil pump and timing cover then the tap will be cutting into those as well. Probably part of your problem.

Jason

fastkevman

Post what size you are using and I will post what size tap it is and where you can get one if I find it.

Matt16

Its a 5/16" helicoil I beleive (I'll check).

fastkevman

Confused here, I would think that it should be metric.
Did you just get a standard heli-coil kit to replace the metric bolt with a standard bolt, or are you mistaken?

Matt16

Lordco said they did make a Heli-coil in the size i needed so we went with what was closest.

Matt16

Here are the details with the helicoil kit I bought:
5/16"-18......(18=TPI?)
Use with a 21/64" bit.