The following will cover general repair of the New Holland knotter, but the general procedure is applicable to other brands as well. As you see the photos, you will probably question why I did not replace a particular part. I will replace any part I consider critical for the performance of the knotter.

Mike Seckinger has over 44 years experience as a farm equipment mechanic in southern Indiana.

These knotters will tie as well as new. With small square balers seldom used in our area, I try and tailor the repair to the customer. I cannot see running up a bill for a customer who only bales a few hundred bales a year, but if the bale count gets into the thousands, then I change my outlook on what gets replaced. All photos were taken from a 1977 315 baler.

Knotter pinion gears

I start with the pinion gears because they are the part that can cause significant damage if not properly maintained. The knotter stack must be shimmed to eliminate excess end play. Heavy-duty knotters use adjustable cams to remove the end play. As the pinion gears wear, the end play increases.

When you get enough end play, the billhook pinion gear can jump time – or jump a tooth. After the billhook finishes its rotation, the billhook will not be in alignment with the knife arm. When the knife arm tries to sweep the knot off the billhook, it cannot because the out-of-position billhook is blocking its path.

If you are lucky, you will only need a knife arm and pinion gears. If you are unlucky, you will break the knotter frame.

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1. This photo is of the twine disc pinions. The pinion face should be flat like the bottom pinion. The twine disc pinion wear will only cause the timing of the twine disc to change slightly.Twine disc pinions.

2. This photo is of the billhook pinions. The corner on the top pinions are worn away. The billhook pinion wear will lead to the pinion jumping time and possibly causing damage to the knotter.

billhook pinions

3. You can check how much rotational play the billhook pinion has by reaching under the knotter and rotating the pinion. It may be hard to see in this photo, but the pinion is not in line with the knife arm. When there is twine in the knotter and hay in the chamber, the billhook is pulled into this position.

You can check how much rotational play the billhook pinion has by reaching under the knotter4. The twine disc pinion will appear to be flat against the large cam gear. Take a 9/16-inch wrench on the nut at the bottom of the pinion shaft and rotate back and forth to see how much wear is present.

The twine disc pinion will appear to be flat against the large cam gear

5. To remove the billhook pinion, raise the knotter frame up until the billhook roller is at the 7 o’clock position. Take a 3/16-inch pin punch and drive out the retaining pin. (The billhook cam and knife arm are removed in this photo. The billhook can be removed without removing either one, but it does make it easier.)

The arrow shows the pin location. The pinion will probably be tight on the billhook. You can put some penetrating oil on the billhook shaft and drive the pinion down. Take a pair of pliers and rotate the billhook and
pull.

To remove the billhook pinion, raise the knotter fram up until the billhook roller is at the 7 o'clock position

6. Before reassembly, a grease port needs to be opened. The top end of the billhook shaft is supposed to be lubricated when the knife arm is greased. Over time, the passage between the knife arm and billhook plugs. The knife arm needs to be removed.

The crossover hole is about 5/8-inch up from the bottom. I take a small screwdriver and put a bend in the shaft. Once you find the opening, you can dig the plug out.

Before reassembly a grease port needs to be opened

7. This photo shows a shim washer on top of the billhook pinion gear. I install a shim between the pinion and the knotter frame. This keeps the bill pulled toward the billhook ramp. This causes the billhook tongue to open wider to catch the twines being held by the twine holder. (The shim is part number 773427 for the New Holland model.)

A shim washer on top of the billhook pioion gear

8. This photo shows the shim location. If the billhook is hard to turn with the shim in place or you cannot install the pin, then remove the shim. Most used balers will accept the shim.

Rotate the knotter up again and install the pin through the pinion and the billhook. The roller of the billhook is directly above the flat surface of the pinion.

The shim location. If the billhook is hard to turn witht he shim in place or you cannot install the pin. then remove the shim.

9. The arrow in this photo shows the needle yoke rod. To replace the twine disc pinion gear, push the needle yoke rod forward as shown. (The shield is removed for photo clarity.)

Arrow shows the needle yoke rod

10. I made a stand (indicated by the arrow) out of a piece of pipe and all-thread. I attach this to the knotter-mounting tab to hold the knotter in position to drive out the pinion retaining pin.

Made a stand (indicated by the arrow) out of a piece of pipe and all -thread

11. The photo shows where the pinion retaining pin is located. You can move the needle yoke to position the pin as shown. In this position, the pin can be driven out with a 3/16-inch pin punch.

In this position, the pinion is engaged with the teeth of the cam gear. I rotate the stand upward, which allows the knotter frame to rotate down until the pinion is against the flat side of the cam. With the flat surface of the pinion against the flat surface of the cam gear, tap the pinion off the shaft and install the new pinion.

While in this position, stick the tapered pin into the hole of the pinion and press the pin against the shaft. Take a 9/16-inch wrench and turn the pinion shaft until you feel the pin catch in the pin opening of the shaft. Check the twine disc timing to be sure you are in the correct position.

If not, rotate the pinion shaft 180 degrees, and you will be in time. Tap the retaining pin into the shaft slightly and then rotate the knotter frame back up and on the stand and finish driving the pin home.

Where the pinion retaining pin is located

12. This photo shows incorrect timing.

This shows incorrect timing

13. This photo shows correct timing, and the arrow indicates the opening in the correct position.

This shows correct timing, and the arrow indicates the opening in the correct position

14. (The shield has been removed for photo clarity.) With the new pinion gears installed, the next step is to adjust the knotter stack end play. Loosen the clamp bolt on the knotter arm and remove the center bolt, washer and shims.

Shield has been removed for photo clarity. With the new pinion gears installed

15. Unpin the knotter frames. When shimming, you want to remove as much of the end play as possible, but you do not want the frames to bind when rotating the frames up and down. If one frame is free and the other is tight, then tap the cam gear to free up the tight frame. Remove shims as necessary.

Unpin the knotter frames

On heavy-duty knotters, the end play is adjusted by cams on the knotter shaft which you rotate one against the other.

New cam gear kits come with hardened pinions, which eliminate much of the pinion wear of the standard pinions.  end mark

Mike Seckinger has over 44 years experience as a farm equipment mechanic in southern Indiana, and says, “What I write is not intended to represent the only way to solve a problem, and it may not always be complete. If you choose to follow some of my procedures, remember to always practice safety first. Wear the correct clothing and safety equipment and use the equipment’s safety devices.”