Impossible Master link

if they're not too hard, could you drill on through the plug and tap the whole depth of the plug to pull it. Or maybe drill through and then insert a driver and drive the other side out (with heat).

I've just spent part of my weekend working on the same thing on my Thirty, except the master pin is welded in (I bet they were sorry they did that - they installed the track backwards!). I ground the welds down, tapped the outer plug, made a fitting and attempted to remove the outer plug with heat and a slide hammer (thanks to some expert advice!). The plug didn't budge, but the whole pin moved out a little. I'm planning to grind out the plugs tomorrow. I'm looking forward to seeing other ideas on this thread!

Maybe I didn't heat it up enough... will I compromise the strength of the metal if I get it red hot? Would it even help? I've managed to remove all the difficult hardware so far with just moderate heat and tapping.

Barstart

Your best bet with the threaded plugs is the slide hammer method and plenty of heat. Because of the taper fit and split pin ends you have to remove the plugs to release the taper fit. If the threads are stripped or damaged you can try welding a stud but there isn't much wall to work with and it takes the full 1/2 in bolt to do the job. Next level is the torch, air or carbon arc removal and it's not real likely the parts can be salvaged.
Also try and focus the heat on the plug and pin end. You're not going to harm the link metallurgy (not hardened at the boss anyway) but you can wind up with an oversized pin hole if you get carried away. (photo courtesy Tractor Don)

I had my plugs glowing cherry red. I then used a large socket around the pin and a piece of all-thread rod to try and pull them out. My pins were only tapped 3/8 and I tightened it to the point of snapping the all-thread and still no luck. That is when the threads in the plug gave out. I might try drilling/tapping the other side to 1/2" and try the slide hammer method.

Can you still buy new master pins with taper locks?

Forget the all thread. It takes a good grade 8 bolt (old wheel lug bolts also work) and a hefty slide hammer to do the job. I don't believe you can get the old style pins and plugs anymore but the straight pins work fine so long as you have a good fit.

Hi smf52,
I need to apologize for giving you some bum information. You are correct the D2 pins are threaded 3/8. It's the D4 & D6 units that are 1/2. All fine threads. Due to the fact that these tapered/threaded pins are heat treated, you will not be able to increase the thread size. Happened to be working on a D6 pin myself and got to thinking. Sorry about that, hope you have good luck with the removal.

I had some of these old style pins to deal with last month on a D8R, I spent some time finding the correct little pulling gizmo for this size track out of my service tool heap ,then set off to the site , only to find the chaps on the site had tried to remove the plugs with some old piece of junk , then popped the cutting torch into the plugs making them a piece of junk also, the correct tool is in three bits , the tread piece , then the spacer this has a square hole in the centre with flats on the outside to fit a spanner, then the nut that you give all the strain to , in the past these plugs always come out easy for me using this tooling, anyhow getting the pin out was a good bit of work , as the same lads had given the pin a nightmare with a hammer , and made a simple job a right " Dog ", so I popped the hydraulic muscle to it and let vintage Dave do the pumping, the pin was tough all the way , but sometimes hard is best,
tctractors

Hi Tony,
Yes, I know of the tooling you are referring to but all they ever did for me was strip the screw threads. Also kind of get in the way when you have to heat the pin boss area as part of the exercise. My best results have been with the slide hammer techniques after several heating and cooling cycles. Sure would like to borrow that pin press of yours😄 😄