Video Transcript: 

Hey, everyone. Christian from MacDon here again today we're going to go through the servicing and adjustments on a double knife header. There's one extra step because you're going to have a unique guard at the center of your head. If your header is a double knife which means it's driven from both ends, you will have a center guard. One thing to be aware of on the 2 Series headers is the center guard is not actually in the center of the header. On previous generations, 1 Series and prior, your center guard was right in the middle where your reel split was. If we look now, the center guard is actually relocated just a little bit over to the left side of the header. Reason for that is you have a gap here in the center between the two reels. The center guard is very commonly mis-adjusted, and if it's mis-adjusted too loose, you end up with a lot of crop buildup on that and you don't have the reel to clean it off. So, you can actually end up with a big strip down your field where your center guard is. For this model, they actually just slightly offset it, and now the center guard will be swept off by the end of the reel on your double reel. And of course if it's a triple reel you've got the center one that's sweeping it off right in the middle.

These are our tools that we're going to use. We've got a pry bar, big impact with the 18mm, small impact with the 10mm, because we know you're going to use an impact, baby torque wrench for the 10mm, 16 mm socket, feeler gauges, and the big torque wrench 18mm for tightening the guards. We want to make sure that you mark this before you take it off. And before I remove it, I'm going to make a mark so I know where to put it back on. I'm going to take off these two guards beside it as well. These are just regular short guards on this particular header or just regular pointed guards. There's nothing significant about it, still got the same backer ledger plate. However, on a double knife header, you've got two knives that stroke in and out, and in fact they actually overlap at the center. The center guard is actually designed for the clearance for two sickle sections to line up on top of each other. If we have a quick look at what's going on down here, you can see this is my left knife and this is my right knife. Notice also that the last section on the left knife is actually inverted. Much like Maverick and Top Gun. This guard, the very last one on the left side is inverted and when we stroke, these two actually cut like that. The bottom sickle is cutting on the guard, the top sickle is actually cutting against the hold down. It's important that you remember when you take this apart and you put it back together again that this one is inverted. If we have a little bit closer look here as well, you're going to see some unique hardware. We have 10mm bolts here, and now we have flush mount bolts that are designed so that the sickle bar can actually glide over top of the other one. If we just had regular bolts, the end of this sickle bar would just keep smashing into the bolt. There's unique hardware at the center section. These sickle sections as well are also unique - this one being inverted is actually countersunk on the underside. And these ones are countersunk as well. These are special sickle sections, we actually sell a kit for just servicing the center part of the knife. I'll pull a couple of these off we'll have a little closer look at them. Here you can see once again we've got flush mount hardware on the underside. Because remember this is going to ride on top of another knife - we are countersunk.

Another thing I want to bring your attention to is underneath the center guard. There is actually a tapered shim here. Be careful if you're stripping the whole knife down and you find this thing on the ground, that's what this is for. It's important that it goes back in the proper location, the end of the shim, the thick end of the shim basically is where the center guard goes. And then it extends this way. When it falls on the ground I'll show you where it came from. It is tapered. We got a thin end and a thick end. Now if you look closely at the guard bar, some of you that have worked on the older generation headers, you'll remember the guard bar was welded on and it was actually welded on offset and that was so that the one knife could travel over the other. If you look on the 2 Series, it's a single formed piece - there's no step to it. How we achieve the two knives going over top of each other is by installing the shim. What happens is this spaces the guards on the left hand side just a little bit lower, that the other one can go over top. You want the tapered end pointed to the right side of the header. If you forget to put this in, you are going to have nothing but trouble, you're probably not going to be able to achieve your proper knife clearance, and you may actually end up with some damage. There's no up or no down. You just got to make sure that this inside is toward the right of the header.

Okay, now we'll reassemble new guard, new poly if we need to, and use the hardware if it's still in good shape. This guard will hold it on for now, and we'll continue replacing our sickle sections and then we'll put this all back together. Remember we've got countersunk special sections from our center overlap kit. We've got our flush mount hardware. This hardware is still in good shape so we're going to reuse it. Now they're in there flush going from underneath, put the nut in, you want the dome side of the nut facing down. And remember, this one goes upside down countersunk on the top. Line it up, then just a snug them up. Torque them to specification, same torqu on these as it is for all the rest of the sections. Again, if we're doing it by feel, it’s one finger. There's really nothing special until it comes to adjusting the center guard, which we will get to. We're going to install these all loosely because I've still got that shim underneath. You want to make sure that there's enough play for that. Remember our center guard, this is the one that's unique, it's got that little step in it so that the one knife can go under and the other can go over. And then our top hold down has three adjusters on it because we now have to adjust the guard this way and also side to side because we're going to have to adjust for those two sections that overlap.

There's our mark we made earlier so we know where the center guard is going to go. And we're going to go through the shim and into place. And then we can snug down all these guards and we’ll torque to specification. Now again we'll check all our hold down for clearance, those ones are pretty good. We won't need to adjust those ones. Now when it comes to the center guard there is a special adjustment procedure. The first thing we need to do is we need to position the knife so that the two guards are stacked up on the right hand side. We're going to have to rotate each knife to bring them both fully stroked in right here. This is the flywheel for our knife, you get in here with a prybar and you can manually rotate this over. And we just want to stroke it until the knife lines up with the guard tip. Now on our center guard we need to check the same clearances, just like we did on the, normal PlugFree™ Knife Guards for you guys, we got to check this one as well. Now there's two places you need to check on - you need to check at the tip. Once again we're looking at that same spec of .004´´ to .020´´ (.1 - .5mm). We've got pretty good clearance there, but that one there is a little bit tight. Now this becomes a little bit tricky because now we're adjusting this way as well as also this way. But we also need to watch our clearance at the back here as well. Normally we just check the clearance at the tips on our normal guards on any double knife. But for the center, you need to make sure that you check it at the tip and also at the back, because it's possible for it to be too tight at the back and too loose at the front, in which case then you have to start working with side to side. This one is a little bit too tight. I've got lots of clearance here at the back, I can have up to .040´´ at the back here. I'm good at the back for right now. This one is just a little bit too tight. What I'm going to do is I'm just going to back off this side, just a hair. Still a little bit too tight. All right, now I'm going to adjust the tilt of the whole guard. I'm going to because I want to basically bring the tip up I'm going to undo this one just a bit. That should tip my guard back now. Okay, I've got a little bit more clearance here. But when I adjust these bolts I can end up loosening these ones. I need to go back and retorque those before I walk away. There we go, it was a little bit loose because I backed off these other bolts. Now we'll see. That may have tightened up. No we're okay there. I'm a snug .010´´ (.25mm). Now this could be maybe a hair tighter if I wanted it to be. I'll bring this side down just a touch. Retract that center one. Yep. See how it got a little bit loose when I ended that bolt. There we go. Nice and snug. There. Almost a little too much there. This can be a little bit finicky. Now if I want to draw that one down I have to back this off because now basically I'm this bolt is pushing against this top part of the guard. You can actually end up cracking this or stripping the bolts. Sometimes you need to actually back off these, with a torque wrench, no supposed to do that! Check this tip. Yep. That's some drag there. That's some drag there. Lots of room at the back.

Now we're assured that we'll have a nice clean cut here at the center. We don't end up with any crop building up in this area and end up with a strip down our field. If you have pointed guards on your header, which a lot of you will have, the procedure is basically identical. There are different components, but you're going to adjust them in the exact same way. Your knives need to both be stroked inboard. You're going to check the clearance at the tip at both tips. That's how good this side is. A little bit loose. Need to check it at the back. Got clearance there. Got clearance there. On this one I'm going to try and bring the tip down just a little bit to snug that up. I'm going to adjust this bolt down. It'll tilt the guard, and then I'm also going to have to make a slight side to side adjustment. I'm going to loosen these ones off, just a hair. I'm going to give this a slight turn. That should tip my guard down, and I'm actually going to back this one off to try and collapse it up a little bit. Very small adjustments here. Snug these back up. Press down, we're using a .010´´ for good clearance there. Good clearance there. Good clearance there. And we'll now just make sure we torque to spec. And one more time, check clearance. That clearance there. Clearance at the tip, clearance at the back. Good to go.

Learn more:
FD2 Series FlexDraper® Header, visit our product page.
FD2 PLUS Series FlexDraper® Header, visit our product page.
D2 Series Combine FlexDraper® Header, visit our product page.
D2 Series Windrower FlexDraper® Header, visit our product page.

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