Hack n Tap broken bit problem

My buddy & I were installing a RE SYE hack n tap on my 99XJ without removing the TC. Everything was going smoothly until he snapped off a bit while drilling a pilot hole in the hacked end of the TC output shaft. It is a 1/16" titanium bit drilled in about 1" deep. The bit broke not only at the end of the hacked shaft but as I soon found out, also about a 1/4" into the shaft. (So there is roughly 3/4 of an inch still in there.) Though it probably wasn't the best idea, we grabbed a slightly larger titanium bit and drilled in until we hit the broken bit and couldn't go any further. If you are familiar with RE's hack n tap system then you will know that there isn't much tolerance for screwing up this hole which will ultimately need to be about 21/64 of an inch when all is said and done. But in the meantime, we are stuck. Can anyone recommend a way to either extract or drill through the 1/16" titanium bit without causing any unnecessary damage to the output shaft?? Any advice would be appreciated.

Thanks:gonnablow

That is why I never recommend using those fancy expensive bits on that job. I use those cheap black Black and Decker bits from WalMart (the kit for $17.96 or so). With those bits and slow speeds with steady pressure, they do the job very quickly. The best part about them is if you break one inside the hole, you take a punch and a hammer, and they shatter into easy to remove pieces (with needle nose pliers). I know that doesn't help your current situation, but it may help someone in the future before they get into that mess. As for what to do, I did have this happen to me before I started the cheapo bit trick. That is a very small bit (I usually start at 1/8" and work my way up). I would get a couple 3/16" bits (cheapos), and start drilling the hole bigger, and go slow speed. You are going to burn up quite a few of these, so cheap is good, so they can be thrown away, or if it breaks again, just shatter it and pull the pieces out. I think I spent 8 hours and about $40 in bits before I got past my broke bit, but it was a much larger titanium. I'm thinking it was 3/16" or maybe a 1/4" bit. That sucked!!!!! Good think you have a buddy, so you can take turns at the drill, because that drill gets heavy when you drill that long. Hopefully someone has a better idea.

Are you laying on the ground doing this install?

Sorry this doesn't help with the bit, but be very careful with the tap. I just installed my RE SYE and snapped the tap off in the hole. It took me a couple hours to get it out. I thought I was totaly screwed for a while, but finally got it out.

You could try a small punch and see if you can get it to shatter in the hole? You might need to continue drilling down to the broken off bit if it chips out a little at a time.

Good luck.

At work we use a variety of tools to get broken bits/taps out. "Easy-outs", small diameter end mills, carbide drill bits. The quickest way is with some type of carbide tool, it won't be the cheapest, but carbide is very brittle so in case the tool you're using breaks it's easy to shatter with a punch. When you do get past the broken drill bit and if you need to drill further, use some cutting lubricant, "tap magic" is a good one.

ROKRWLR brought up a good point. I've install a lot of these now and here are some tricks I use to knock the install time down to about 45 minutes.

For the drilling, I already covered the cheap bits thing. To make the whole process easier, don't do it with the jeep on it's tires and your laying on the ground. Get it up on jackstands or ramps, so you are sitting flat on your butt with your head in the tunnel looking directly at the end of the shaft. Thsi way you can drill directly into the end of the shaft instead of laying on the ground where you can't get a good eye on if you are drilling at an angle or putting angular stress on the bit. Let the bit do the work. Drill straight, and slow. If you drill fast, it just heats up and then it gets tough.

For the tapping, this will sound like a slow process, but it actually makes it go really fast with little risk of breaking the tap. have some cutting oil (motor oil works fine for me), the tap, and a can of brakefree on hand. Get the tap started about 1/4". Back the tap out, clean out the hole and the tap with the brakefree. add some more oil, tap in another 1/4". While tapping, I do one full turn in, back it out one full turn, thread back in and cut another full turn, back it out, etc., until you get 1/4". take the tap completely out, spray the tap and hole with break free to clear out all the debris. Continue the 1/4" cut and clean until you bottom out. The tap cuts very quick and clean when you keep removing all the garbage out of the way. Be sure you don't look directly at the end of the shaft and wear safety goggles when you spray the brakefree in the hole, because it will shoot right back out at you. I learned this once (stupid!) and that slowed the process down for a little while.

When you go to put the flange on, the tolerance is very tight. Have a fine grit triangular file and clean the burrs out of the splines at the end where you cut the shaft. if you put a drop light in around the shaft, you can look directly into the bolt hole of the flange and line up the splines just right. Slowly turn the flange lining up the splines until you find the sweet spot that the flange grabs on, then lightly slid it on. A small rubber mallot and some light taps dead center of the flange will help it go on. Don't force it on or get over zealous with the mallot, because then you will burr up the grooves, and the flange will stop, then you get to pull the flange off and have fun cleaning the burrs out of the splines. I have done it all, and it may sound like I just don't know what the heck I'm doing, but stuff happens that you learn from after doing so many, and hopefully my lessons learned will help others that have no experience keep from making this simple install into a nightmare.

This is natures/Karma's/Gods (pick your favorite) way of telling you to buy the PORC SYE so you can throw away the damaged shaft, install a new one and get a much stronger output shaft/rear bearing support combo in the process.

John

You can also start with a new output shaft. Seems like a lot of people, me included, have their old shafts sitting around doing nothing.

Do you have an NP242?

I broke the tap off in mine and couldn't get it out. I'm sure someone with a ED machine could have burned it out. You have a better chance on getting the bit out than I had getting the tap out, though.

I ended buying a new t-case (NP242 with 16k miles and a gouged case) for 150.00. I then brought in the mainshaft and let a guy do it on his mill. I'll never do another Hack and tap. I'd rather buy a 231 or Atlas/Stak.

Thanks to everyone for all the feedback thus far. Yes, I do have an NP242. I spent a few hours yesterday trying to drill the bit out using both left handed cobalt bits and regular titanium bits. To be honest, I don't think I made any noticeable progress. So far I have been trying to do this on the vehicle while lying on my back underneath it. I am going to take another stab at it with some fresh sharp bits but if that doesn't work then it will be time for a plan B. I am still open to ideas so please keep them coming. Thanks

i would start a new thread bud requesting some ones shaft thats collecting dust...some one will help yeah out...

I installed the whole kit with a new shaft and tail housing. I saved the old shaft if you need it. 98 XJ

When I broke the 1/16 bit doing mine, by going up to near the final size and drilling up to the broken piece, I was able pull it out with a small magnet.

And I think they should not recommend starting with that small of a bit. Maybe if you have it on a drill press, but not working under the jeep.

Two words: car bide
Ok, one word, try it. Carbide tooling should get anything out, except diamond impregnated tooling.

If all else fails, which situation I have been in a time or two, find a disintegrator. My local guy is no longer there, but came in handy more than once. I had him disintegrate broken exhaust bolts and drill bits out of aluminum heads. Took the heads to him clean, and he charged $35 each, took about 4 days to get them back (he was backlogged). The disintegrator mounts on a turret lathe head, and uses an arc to do the work. It will remove material very accurately. He was able to disintegrate the bolts and drill bits without doing one iota of damage to the original aluminum threads! Truly amazing. I wish he was still there. If you can find a shop with one, it's a priceless solution for a reasonable price.

i did the same thing may yearts ago ,, I had to get a new sahft and start over ..ended up pulling the shaft form the t case anyway.sucked arse

I have a spare 242 shaft. PM me if you need it.

A dremel with a carbide "drill" bit. The bit I'm taking about looks kind of like a standard drill bit but has shallower flutes. I've used that to grind out various broken bits, bolts, etc.

Hey thanks again to everyone for the feedback. I am going to try a couple of things this weekend and hope for the best. If I can't make any progress then I may have to reach out for an extra shaft some of you have laying around. I'll keep you posted.

Thanks again.

I know it doesnt do you much good now, sorry bout that, but maybe it will help someone in the future.
I know RE suggests using a bit smaller than 1/8" for a pilot but in the 3 H&Ts Ive done, I never used a bit that small because I didnt want to break it off. I always went a couple sizes bigger than 1/8" and its worked out well. Its just too easy to break those small bits.

To get high tensile broken bolts out of the block, engine mount, you heat the bolt with a torch until cherry red. Let cool slowly and that takes the temper out of it. You could then drill it out with a regular drill bit. Maybe you can do this with the shaft too? Not sure though if it would effect the case hardening on the outside of the shaft though? Anyone know as the heat would be concentrated only in the hole but some would travel to the outside? Only need the drill bit up to cherry red which would be pretty quick and not that hot so outside should be quite a bit less?