Hacking and tapping.

nosdujshsdl said:
how are you all drilling the center hole perfectly straight, Im having a bit of trouble trying to figure that out, going to do a hnt on mine this weekend.
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Use the same method: Jeep in reverse, shaft spinning. The drill will have no choice but to go exactly straight since you basically made a lathe. Just take it slow. Don't use too small of a bit for a pilot but don't go too large either. The shaft is pretty soft so you should not have any problems. I used my Firestorm cordless with the torque setting set back a bit so if the bit gets stuck it won't break. As everybody said, take it extra slow when you tap the hole. I went one eight turns at a time with insane amounts of oil to lube it. I backed it all the way out every half turn or so to clean it. Just go back and forth, and DO NOT FORCE IT.
 
Last night I cut the tail off my output shaft using the "vehicle-in-reverse method". My cut off wheel on my angle grinder cut through it like butter in a few mins. Made a perfectly straight cut and did even need to clean up the splines! Awesome.

So that went great, but I drilled my pilot hole, and I thought it was in the middle, but it's not...shite!
 
Graeme said:
Last night I cut the tail off my output shaft using the "vehicle-in-reverse method". My cut off wheel on my angle grinder cut through it like butter in a few mins. Made a perfectly straight cut and did even need to clean up the splines! Awesome.

So that went great, but I drilled my pilot hole, and I thought it was in the middle, but it's not...shite!
Click to expand...

plug weld the yoke on... thats what i did lol.

lasted me 8 months, then the truck got scrapped. never leaked.
 
Graeme said:
Last night I cut the tail off my output shaft using the "vehicle-in-reverse method". My cut off wheel on my angle grinder cut through it like butter in a few mins. Made a perfectly straight cut and did even need to clean up the splines! Awesome.

So that went great, but I drilled my pilot hole, and I thought it was in the middle, but it's not...shite!
Click to expand...

As long as you can get the bolt in, it will be fine.
 
x2. like i said, the hole does not need to be PERFECTLY centered. you just need to get the bolt in. the only point of the hole is to bolt the flange on.
 
1990JEEPXJ said:
x2. like i said, the hole does not need to be PERFECTLY centered. you just need to get the bolt in. the only point of the hole is to bolt the flange on.
Click to expand...

REALLY? I would think that having the bolt - and then the flange, since its location is determined by the bolt - off center would throw the whole thing off balance when in fast rotation, making for terrible vibes. And isn't part of the point to reduce vibes?

Please, explain how I am wrong, because this is one of the things holding me back from trying to do this very mod myself - fear of not being able to center the bolt hole.
 
katuah said:
REALLY? I would think that having the bolt - and then the flange, since its location is determined by the bolt - off center would throw the whole thing off balance when in fast rotation, making for terrible vibes. And isn't part of the point to reduce vibes?

Please, explain how I am wrong, because this is one of the things holding me back from trying to do this very mod myself - fear of not being able to center the bolt hole.
Click to expand...

The bolt does not center the flange. The splines center the flange. The bolt just holds it on.
 
obviously if you are very far off yes. i think if you are far enough to cause a problem, you wont even be able to get the bolt through the hole in the flange anyway. but being slightly off wont cause a problem. the bolt does not determine the placement of the flange, the output shaft splines do.
 
I would think that without removing the shaft it would almost impossible to get it PERFECT.

Having said that, I did mine with the transfer case still installed and used a washer that was the same diameter of the shaft to help me center punch the area to be drilled. If you have some transfer punches it really helps.

If you don't have some, then get some for the "shop" aka garage. They help with lots of things.

Think about it. If all these guys were having issues with the hole not being perfectly centered it would be a well know issue by now. There are plenty enough other things in these rigs that make more n.h.v. then the less than perfect bolt hole.

Just my .02
 
to get mine centered i put a dot on the shaft with a sharpie and spun the shaft to make sure it didnt wobble. when i got the dot perfectly centered i hit the center of the dot with a punch and then used a fairly small bit to make a pilot hole. i dont think i could have got it more centered without removing the shaft
 
Don't forget loctite on the bolt holding the yoke in!!

I forgot it on mine. Fortunately it came off while driving slowly, so damage was minimal. Bolted it back up and used loctite and no problems since.
 
Well my bolt is definately not centered, but I have been driving it and there are no vibes. So nice to have a smooth jeep again! I didn't realise just how bad it was.

Two of my bolts broke off in the yoke on the differential. I just drilled the holes right through then put in some 1/4"( i think), nuts and bolts to hold the u-joint "strap" on. I'm such a redneck...but it works and is smooth!
 
Ivan said:
With your rig OUT OF 4 wheel drive, and your wheels blocked so your rig doesn't roll; start the engine, and put the tranny in reverse. This will allow the tailshaft to spin in the correct direction. Take the power saw and begin your cut while the tail shaft spins. The tailshaft doesn't really spin all that fast in idle. The counter rotations of the tailshaft and the saw blade will keep everything steady. The cut will take less than a minute, and the cut surface will be surprisingly straight.

...

Definately take your time tapping. A quick start with generous amounts of cuttng oil, back out and clean about every 1/4 turn of the tap. Don't rush this step, as removing a broken tap is a real pain....
Click to expand...

When your cut is done, don't just put it into park as you have no way to slow the driveline before doing so. Turn off the engine, let the drivetrain slow itself to a stop, then place the shifter in park or neutral, as you see fit.

I know the author wasn't suggesting this but I want to make this absolutely clear for anyone who has never drilled and tapped anything:

Cutting with the tailshaft spinning is a great idea however...

:skull1: DO NOT try to tap the tailshaft with it spinning! :skull1:
 
I just got the (yoke style) hack & tap Sye from dirt bound offroad and it didn't come with directions.

How much of the shaft do I cut off? I have a little over 5" of lift on my xj with an 8.25, is a front shaft going to be the correct length?

Im a little disappointed that there aren't any directions with the kit ir on their website.
 
XJ jay said:
drill and tap extra slow. i busted the tap off a few weekends ago. it took me an hour to get 95% of it removed so that i could retap it. no amount of drilling or chiseling the tap would get it out. i had to carefully use a cut of torch to blow the tap out.
Click to expand...

If you ever run into this again Walton makes tap extractors- they pretty much the sure thing to get a broken tap out- they grab the flutting of the tap.

http://www.waltontools.com/products/extractr.htm

As far as hacking and tapping I am not a fan- but it is a necessary evil if you don't want to/can't spend the green on a modified mainshaft.

I agree with the cutting in reverse with a metal cut off disc and either circular or die grinder. Of course don't get yourself killed in the process.. duh. :yelclap:

I have seen rigs with the 242 HnT method done well and not so well :)- I would use the flange as a guide for the hole. slide it on the shaft, center punch through the flange hole- then use a small socket or drill bit guide (nothing more than a hollow shank) to drill a smaller hole and progressively work one bit size up at a time increasing the guide size as you do. That way the bolt is centered. Centered is ideal.. but then again it is called hack and tap for a reason.

Sucessful drill is SLOW drill speed, sharp bit, cutting oil, or in a pinch motor oil-, a right angle handle on your drill helps.
 
Last edited:
dfarmxj said:
I just got the (yoke style) hack & tap Sye from dirt bound offroad and it didn't come with directions.

How much of the shaft do I cut off? I have a little over 5" of lift on my xj with an 8.25, is a front shaft going to be the correct length?

Im a little disappointed that there aren't any directions with the kit ir on their website.
Click to expand...

The instructions are on the website. www.ironrockoffroad.com/Merchant2/m...ode=IROR&Product_Code=IR-XHNTY&Category_Code=

Sent from my DROIDX using Tapatalk
 
Thanks for that link. I'm going to be attempting this job today. I hope everything goes well. The only part that makes me nervous is making sure to get the cut in the right place. I'll probably measure 5 or 10 times before I cut. Lol.
 
Depending on your rear axle, the IRO instructions can be slightly in error. It is best to cut the T-Case output shaft about 3/4" longer than you measured/calculated and then test fit the yoke. You an always cut the shaft shorter. ( If necessary, you can also trim the yoke to fit a too short output shaft. )
 
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