Dogleg screws

[Matt Kirsch]

Last weekend I finally got brave enough to attempt drilling out the twisted-off dogleg screws in the front bolster. I went into the job thinking all four were screwed up, but only three needed help.

The two on the left side went great. On the other side, though, the steering box got in the way. Luckily I only had to drill one, but wouldn't you know it, the one I had to drill was the hard one to get to (rear). This one ended up a little off-center, but it's functional, so I don't really mind.

I was freaking out and fretting because I was afraid of drilling through into the lower radiator tank. You'd have to be pretty slow on the uptake to do that, as I found out.

There seems to be a cavity in the casting between the outer bolster and the lower radiator tank!!! After drilling through less than the requisite 1/2" I broke through into a cavity. No green stuff came out. On the second hole, the screw caught the drill bit and spun into this cavity.

[beaconlight]

Good luck is the best kind.


Bill

[John Niekamp]

Matt,

That is more common than you think. That's why I always try to use a left-handed helix drill (no joke) when drilling out bolts studs, things of this nature. We have several sizes at work, by 1/64 th but I only keep a few common sizes here at home.

It's nice when your about to break through the end of the screw/bolt and all of a sudden it grabs and starts unscrewing itself. sometimes even before that.

AND in your case not drilling through to the tank cavity..... GOOD JOB!

John

[johnbron]

Ironic that this post shows up just now. I was working on the dog-legs a bit ago cleaning & chasing the threads on the lower dog-leg screw holes and the back bottom one was missing on one side which I thought was broken off. SO seening what I THOUGHT was broken off turned ugly. My first attempt at drilling it out broke a brand new sharp drill bit. I thought this sure seems to be awfully hard material to drill for a common screw. SO I tried another bit and got nowhere and then realized what (I-think) that I am trying to drill into is a previous persons broken off easy-out remains.

[Larry in IN]

JB:
That is sure an interesting situation.
Please advise as you get around to solving that one
I suspect that Rudi will want pics and a play-by-play
Murphy (of Murphy's law for you young'uns) was an optomist!

[John Niekamp]

:o Ironic that this post shows up just now. I was working on the dog-legs a bit ago cleaning & chasing the threads on the lower dog-leg screw holes and the back bottom one was missing on one side which I thought was broken off. SO seening what I THOUGHT was broken off turned ugly. My first attempt at drilling it out broke a brand new sharp drill bit. I thought this sure seems to be awfully hard material to drill for a common screw. SO I tried another bit and got nowhere and then realized what (I-think) that I am trying to drill into is a previous persons broken off easy-out remains.

JB,

This is something I've had to overcome many times myself. People trying to save money (can't blame em any) will try to drill out a broken bolts and I have found drill bits, taps and easy-outs remaining in the hole. Even a few times found both a drill bit and a partial easy-out broken in the hole.

What happens then, by the time they decide to bring it into the machine shop, it's usually to late. Generally the problem is because they do not get in the center of the bolt or scew and you will have to use a heli-coil, keen-sert and even make your own special plug. I have seen just about everything over the years.

When there is a broken tap or easy-out in the part, if possible, we will clamp it up on a milling table and try to use a CARBIDE drill bit or end mill to get through the hard material and hope that we can get it back in the center of the hole at that time. On your bolster since it's already mounted on the tractor a milling machine is out of the question. You may try to use a hand drill as I have in the past and get through it. There is some special carbide tap removers, if you want to pay the price.

THEN is all else fails, we have a EDM (disintegrator) machine to melt those stubborn objects out.

I "think" (just been a couple of weeks) these screws for the dog legs are #10-24, so your tap/drill size is #25, (.1495") getting a little small, SO I wasn't gonna mess with a small screw and since the 24 TPI pitch is one of the worst pitches to tap. I made mine on both of my Cubs 1/4-20, (YEAH, I know that isn't correct) If you don't have to drill it to far out, you may be able to use a heli-coil or keen-sert in it to keep it at the original tap size.

Good luck, just be careful if you use a carbide drill bit, carbide is very brittle and will NOT take any or very little impact and will break into many SHARP pieces. SO be sure to wear your saftey glasess or goggles.

John

[Matt Kirsch]

Well, pshaw... As I said, you gotta be pretty dim to drill through the lower radiator tank, because there's a cavity up in there between the dogleg screw holes and the radiator tank.

I've always wondered if it would be possible to carefully chew out a broken-off easyout with a diamond tipped Dremel bit. Diamond is harder than carbide.

[johnbron]

I've always wondered if it would be possible to carefully chew out a broken-off easyout with a diamond tipped Dremel bit. Diamond is harder than carbide.

Well, If I ever come across a diamond bit I might just give that a try. But, until then I have decided it isn`t worth the trouble involved to worry about it and so for now it shall remain screwless.