The following instructions will cover general repair of the twine disc and twine holder on the New Holland small square baler, but the general procedure is applicable to other brands as well. (All photos were taken from a 1977 315 baler.)

To replace the twine disc, remove the knife arm and billhook. Remove the twine holder spring. Remove the pin from the twine disc gear and remove the gear. The twine disc and cleaner discs can be removed. Install the new disc and pin. The twine disc will probably need to be re-timed. To time the twine disc, loosen the nut at the end of the twine disc worm gear.

Take a hammer and tap on the end of the shaft at the nut. The worm gear is on a tapered shaft. Once the gear is free, then the twine disc can be positioned so the twine holder covers the twine disc notch by a quarter-inch with no twine in the knotter. Turn the loose worm gear to take up the slack in the gears and tighten the nut.

Trip the knotter and recheck it. It is not uncommon to have to make the adjustment several times until it is right.

When the twine disc is timed properly, the twine holder will extend a quarter-inch over the opening of the twine disc notch when there is no twine in the twine disc.

When baling with twine in the twine disc, the twine will push the holder to the side so the holder only extends an eighth of an inch over the slot.

I seldom replace twine discs. If you look closely at the notch on this twine disc, you will see it is elongated from wear. If this baler was used heavily, I would probably replace this disc. The wear on the twine disc is not as critical as the wear on the twine holder. As the notch elongates, the twine clamping surface does not change except it moves down the disc. The twine holder, however, does wear in one spot, and the holder tension will change on the twine.

If the knotter is not missing knots because of the twine disc timing, I will not change the twine disc timing even if it is not to “book specs.” I have run into situations where changing the twine disc timing to “book specs” caused knotter tying problems.

A good way to check if the twine disc timing is where it needs to be is by baling some hay and stopping the tractor right before the knotter trips. Once the tractor is off, trip the knotter and have someone turn the flywheel. Watch as the twine is delivered to the twine disc, and then watch as the billhook rotates. As the billhook rotates around, the tongue opens. If the twine disc is in proper time, the two twines will enter the open mouth of the billhook without touching the billhook.

To remove the twine holder on the peened pin, the twine disc pinion gear needs to be removed and the pinion shaft removed from the knotter frame. The billhook will also need to be removed. Take a punch and drive the pin down, out of the frame. Install a new twine holder and insert a new pin. I use a center punch to spread the top of the pin.

The button-head style only requires the removal of the billhook. Remove the screw and replace the twine holder.

On the straight slotted pin style, you only need to remove the twine holder spring and you can wiggle the twine holder out.

I always replace the twine holder springs when replacing the twine holder.

I use a 1-inch shaft to hold the frame while I drive the twine holder pin out of the knotter frame.  

PHOTOS: Photos provided by Mike Seckinger.

Mike Seckinger has over 44 years of 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.”