Asked similar question, but included Fiat-Allis in my title and I think that got me passed over by many. Pretend you never heard that, and let's talk rails in general. Let's say you had a "farm" dozer, 100-200 hrs per year max. Parts are in pretty good shape, but one side the tensioner is maxed out and still double the recommended slack, in fact the track is so for forward that on a slope with the blade up sometimes the arm to the blade contacts the pads. Would like to remove a link, but haven't been able to locate any pins/bushings for this metric nightmare. Another individual recommended cutting two adjacent links in half, and then welding the front of one to the rear of the other, essentially removing one link, using the track pad bolts to hold the link halves together while welding them back. I don't have a pin press, nor do I want to spend the money on one nor pay a 2-3k service call for the work, as I m going to change the sprocket while I have the rail loose. How can I do this the easiest by myself or with one helper in the off chance I can get one for a few hours.
Well, while it is not a recommended fix, what you suggested may work for a machine used gently and with low hours. Just be sure you make the cuts in a way that they will match up, and watch that you do not distort the alignment as you weld. I have done the same thing before on D-8K's to get a job finished, so it will work.
If you are cutting a link out you only need a master pin. If the chain is worn that bad it won't matter that a different master might not be the perfect fit anyway. Just install it and weld a piece of bar stock or something over the end.
Okay, either you have a split master where the links are bolted together through the pad, or you have a master pin. If it's split links, unbolt it. If it has a master pin, the short version is that with heat and some proper tools and BFH along with some volunteer with lots of muscles, you drive the master pin out. Torch off the links with the master bushing in them and remove the pin from the next bushing back, grind the ends of the now exposed bushing flush with the links, reassemble, using more heat and the same really big hammer. It's VERY helpful to have new master pin kits but not always essential. YMMV
So, dumb question, but if all pins will drive out, what's special about the master? I assume the pins will drive out either direction, but of course I will be driving them off from the outside towards the center of machine, BUT, will they drive back in the same way, from outside to center? Don't want to completely remove the track from machine to drive pins back in from the other direction if I don't have to. These are not alligator / bolt together links.
With master pin type links then that pin is just a couple of thousandths smaller in diameter than a standard pin to enable it to be driven out using slightly less effort. The master pin often has a dimple in the end of the pin so that it stands out from the rest, not sure whether Fiat-Allis links have this but it makes sense that there has to be some way of identifying the master pin. If you drive a pin out from "outside to inside" you can drive it back in the same direction. It doesn't have to go back in the same way it came out.
If you have a torch, you can save a lot of hammer swinging by cutting the pin bosses on the link you are going to remove allowing the pin to be driven out much easier. Then you can sacrifice the pin on the other end of that link. Gouge into the end of the pin with the torch an inch or so deep and cut a notch over to but not into the pin boss. Let it cool and it will drive out comparatively easy. If you don't get out of control and cut the wrong parts you will have the parts to put it back together correctly.
That's the info I was looking for right there. I will do some counting and measuring before i start that.
I think CDUB is right on the money. Worst case scenario, is you get a track pin that's close to the size you need, and just have it machined down slightly. Or for the amount you use the machine you could probably just use a grinder and weld the pin in.
Master pins are usually turned down in the center with just the end section that are tight in the link ears full or near full diameter. This is so once you get the first end past the outside link it will slip easily all the way to the other link, without having to beat the snot out of it all the way. A few minutes at the bench grinder with a standard pin can make the conversion if needed.
The master pin /link assy has a shorter bush with a spacers to make up for shorter bush length so the chain will separate ,if you try to split the chain at any other point the chain will not separate due to the bush extension in to the next link Mark
ihmanky, Glad you started another thread, I wouldn't want you trying my suggestion without seeking other opinions. The thing is, this was recommended to me 20 years ago after I split the chain on our 14C by driving out the master pin. Drove the same pin back in but it became loose in short order. Tried welding some bar on the ends of the pin to hold it in place but it ended up flogging the link bosses out. Ended up cutting out the offending pin and welding in a new one along with half links on either side. Bolted the track plates back on to hold everything aligned before welding. This chain is still in service and has even been through a track press after I replaced pins and bushes and forgot to tell the track shop about the "bodgy" links. Iam sure there are others out there that have done the same thing. Cheers, Greg
The new sprockets you plan on installing will be a waste of money. They will not match your stretched out tracks and will be climbing and junk in short order. I would just weld up the old ones a bit in place if they are jumping and run them along with whats left of your rails to distruction. Save the new sprockets for when you get new rails.
Mark makes a good point. If you want to split the track in order to remove a link you need to locate the master link and split it at that point in order to potentially avoid all sorts of trouble. The diagram below may help you make sense of it; it attempts to show what the master pin joint looks like and also what a "standard" (non-master pin) joint looks like. The top of the diagram is the master pin joint. As you can see the end of the bush is installed flush with the outside surface of the inside link and there is a spacer that fills the gap between the end of said bush and the seals that are recessed in the bottom of the counterbore of the outside link. When you drive this pin out the track will separate leaving the spacer and seals inside the outer link. Well they will probably fall out as everything comes apart but at least that is the theory. Now look at the bottom of the diagram. On the standard link there is no spacer and the (longer) bush protrudes out of the inner link into the counterbore on the inside of the outer link, leaving only just enough space for the seals at each end. Drive this pin out and the track will NOT separate because it will still being held together by the bush.
I have some photos from an excavator I did several years ago. I'm trying to remember how to do multiple files in one thread so I apologize in advance if I mess this up.
I guess I did.
Oops, got the standard bushing in there twice. Here is a standard pin that I burned the ends out so I could keep the links intact. Once cut they release the press fit and they knock out with a small sledge.
Here is a look at a standard bushing. When you cut a link out you can take a torch and cut the center out of the bushing and then slit the ends inside the link to remove it.
TBH you can bash away at a pin and all that but the easiest way is to unbolt 2 plates,cut a link out cutting the link in half between the holes,pull track together and bolt pad on and weld up. Half hour job. Bill.
I've done this a few times to get by on older machines. As others have mentioned I always cut out one pin and sacrifice one link. The pin that was inside the sacrificial link can be ground down slightly so it pounds in easier. A little weld in the ends of the pin to keep it in and you're ready to go. This process takes a bit longer than simply welding two links together but there is no questions on weld quality.