Shear Bar Options and Installation on a 7000 Series John Deere® Forage Harvester
February 24, 2022 | Ag Parts
Ever wondered what shear bar would be best for you? Nolan is here to help you decide! Find out about the differences and which shear bar would be best for you and your 7000 series John Deere® forage harvester and how to install them!
Kooima Ag Shearbars
Let’s get started with our 7000 series machine! At Kooima® Ag, we offer the most variety of shear bars. These range from grass shear bars, corn shear bars, high-performance shear bars (grass and corn), and double sine wave shear bars (grass and corn). We are going to go over each of these bars a little bit before jumping into the installation.
First, the grass shear bar – K53905. This is a very good bar; it is coated on the cutting edge and the top edge – we call this a corner coat. We choose the corner coat for this bar because, when foreign objects come in such as rocks, they like to chip your carbide. This will cause you to lose the edge on your bar. Typically, if the rock is small enough, it will only chip the front edge and not damage the cutting edge. So, we like to corner cap pickup applications such as grass.
Secondly, the corn bar – K53906. We strictly put the coating on the edges of the corn bar. This is so you get a wear-sharp application on the corn. There shouldn’t be a lot of foreign objects coming in with corn, but it can happen.
Thirdly, let's talk about our high-performance shear bar – K53906HP and K64735HP both work for grass and corn. This is our biggest seller. If you don’t want to buy strictly grass or corn, then this is the bar for you! This bar is corner capped on both sides so, if it wears out on one side, you can turn it around to use the other side. There is a coating all through the center, so it stays sharp.
Double Sine Wave Shearbars
Finally, our last bar, the double sine wave shear bar – K53906DSW & K64735DSW. This is a new invention we’ve come out with in the last few years. This bar has swirly, sine waves on it. It also has more cutting surface on it. The reason a lot of people like this bar is because, when material comes through to get chopped, it will get held in place making the length of the cut more consistent. This bar also has all of the carbide on it through the top. When one side wears out, you can easily flip it around and use the other side.
All of our bars require a wear strip – K49450 (all 6000 series and all 7200-7580 series) & K724870 (7700-7980). All of our wear strips have two colors on them. One side is more gold, and the other side is more grey. The grey side always touches the bar. So, the Grey will face up on the bottom of the shear bar and down on the top.
How to install a Shearbar
Now that we covered the different styles of shear bars, we are going to start installing them on the 7000 series John Deere® forage harvester. First, you will need to remove the old shear bar. Take out the old bolts from the shear bar. Then, take off the old wear plates and remove the bar.
Before installing the new bar, you will want to thoroughly clean the surfaces. It is very rusty and dirty, so use a screwdriver or chisel to peel it off. While doing this, be careful not to hit your hand on the knives.
Now, you can start installing the new, high-performance shear bar. Place the wear strip grey side facing up. Then, take your shear bar and place it on top of the wear plate. Next, you will grab the top wear plates. These will go grey side facing down and gold side facing up. Then you will place the block back in place. It can be tricky lining all of the holes up, but once they are you can use your K64735HPBK hardware kit to secure the shear bar in place. Careful not to tighten them because the bars are purposefully bowed. This is because there are no bolts holding them in the center, so they bow up on the edges. So, if you put a lot of pressure on one side, you will start to lift the other side. You will want to just start it until the other side is ready. Once everything is started, you will torque the bolts, but not before you add on the smaller bolts.
Snug up all the bolts before moving on to torquing them. We will start by torquing the middle bolt first. You will want to set your torque wrench to 175-foot pounds for the center bolts. The outside bolts are only torqued to 66-foot pounds. Your manual will have all of the specs for what torque is needed. You can bring the center ones down a little bit more now also. Now grab your torque wrench and start at 175-foot pounds for your center bolts. Now reset your wrench for 66-foot pounds for the outside bolts. Once this is done, the shear bar is installed. It is very important to make sure that the knives clear the new shear bar. It is nice to do this before the cutter is running and everything is closed up. Sometimes shear bars can seem intimidating, but just make sure everything is cleaned and torqued properly the wear strips are facing the right way. You are now ready to go chop some grass and corn.
Installing the Double Sine Wave Shearbar
Now, let’s install the double sine wave bar. Remove the old bar – be sure you are doing it evenly again as if you loosen the one side too much the tightness of the other side will bring up the loose side of the shear bar. Again, the grey side faces the shear bar. Tighten the center bolts evenly since the shear bar is purposefully bowed. Start all of the bolts but do not tighten them as they will need to be torqued. We are just about finished installing the wave shear bar. Check the knives to make sure none are hitting the shear bar. This will help you get very consistent lengths when chopping. Torque your center bolts to 175-foot pounds and the outer bolts to 66-foot pounds. You are now ready to get chopping!