Round Baler Troubleshooting: Fix the 12 Most Common Problems

Symptom: Bale is wider at the ends than in the center, producing a waist or hourglass shape when viewed from the side.

Cause 1 (most likely): Center belts are worn longer than outer belts, creating a concave surface in the bale chamber center. The crop fills the longer-belt zone (center) less aggressively than the sides, producing the hourglass waist. Measure all belt circumferences; replace any belt more than 2% longer than the shortest belt in the set.

Cause 2: Pickup delivery is too narrow — crop is entering the chamber on a narrow center path rather than distributed across the full pickup width. Check that all pickup tines are present and at equal height; clear any partial-width blockage in the crop conveyor.

Cause 3: Center roller wear — if the center chamber roller is worn to a smaller diameter than the outer rollers, crop pressure in the center zone is reduced.

Symptom: Bale has a flat face on one side and is rounded on the other — D-shape when viewed from the end.

Cause 1 (most likely): One side of the pickup is consistently delivering less crop than the other — a missing tine section, partial crop lane blockage, or windrow not centered under the pickup. Verify windrow centering; walk the pickup to confirm all tines are present and at equal height across the full width.

Cause 2: Belts on one side of the baler are longer than the other side — the longer-belt side fills faster, creating an asymmetric bale. Measure and sort belts; replace any belt more than 1.5% longer than the shortest belt in the set.

Cause 3: Tailgate hinge is misaligned — if the tailgate does not close symmetrically, one side of the bale chamber is slightly larger than the other, producing asymmetric bale shape.

Symptom: Finished bale feels firm on the outside but has a soft, loose core that collapses when the net wrap is removed.

Cause 1 (most likely): Bale started forming before the chamber was producing adequate tension — the initial core was formed under low-tension conditions before density pressure built up. This is common with fixed-chamber balers when the first windrow entry is too light or too narrow. Ensure a full-width, consistent windrow entry at the start of each bale.

Cause 2: Belt tension springs are weakened — insufficient spring tension in the early stage of bale formation allows the bale core to form under insufficient compression. Check spring tension against manufacturer specification; replace springs showing more than 10% compression set.

Cause 3 (variable-chamber only): Density control valve is not applying pressure correctly at the beginning of the formation cycle — the electronic or hydraulic density system may need recalibration.

Symptom: Bales consistently weigh 15–25% less than the baler’s specification at maximum density setting, even with correct windrow volume.

Cause 1 (most likely): Belts are worn and elongated — a belt set at 2–3% elongation has significantly less tension-generating capacity at equivalent spring compression, producing lower-density bales. Measure all belts; replace the set if average elongation exceeds 2%.

Cause 2: Crop moisture is too low — very dry hay (below 10% moisture) does not compact as efficiently as hay at 14–18% moisture. This is a crop-condition limitation, not a mechanical fault.

Cause 3: Belt tension springs have weakened from age and use — the spring’s free length has shortened, meaning it cannot generate the same force at the same extension point. Replace springs every 3–5 seasons as preventive maintenance.

Symptom: Wrap alarm triggers; arm extends to wrap position; bale rotates but no net is feeding into the chamber; bale ejects without wrapping.

Cause 1 (most likely): Net roll end or net feedout jam — a fold, crease, or corner tear in the net has caught in the feedout mechanism. Stop, disengage PTO, open access cover, and manually clear the net path from the roll through the feedout slot.

Cause 2: Net brake tension too high — excessive brake tension prevents the roll from rotating freely when the arm pulls net. Check brake pad pressure; correct specification is in the operator’s manual.

Cause 3: Net roll core slippage — the net has pulled free of the core and is spinning loose inside the roll holder. Replace net roll.

Symptom: Net wraps correctly; cut cycle activates; arm retracts but net remains connected between bale and roll — the bale ejects and pulls the remaining net off the roll, jamming the feedout system or tangling in the chamber.

Cause 1 (most likely): Knife blade is dull or chipped. Test with thumbnail — the knife edge should catch clearly on your thumbnail; a smooth-feeling edge is a dull blade. Replace knife blade. The correct knife type and replacement procedure is in the baler parts replacement guide.

Cause 2: Knife stroke is not reaching the net — the knife actuator travel is insufficient to bring the blade across the full net width. Check hydraulic cylinder extension or mechanical cam travel against specification.

Cause 3: Net twist — the net has developed a twist in the feedout path that changes the angle at which it contacts the knife, causing a partial rather than complete cut. Reload the net, ensuring it feeds flat and untwisted through the entire feedout path.

Symptom: Finished bale has good net coverage on one face but poor or missing coverage on the other — the net concentrated at one end rather than distributing across the full bale width.

Cause 1 (most likely): Net feedout arm travel is restricted — the arm is not traveling fully to the opposite end of the bale during the wrap cycle. Check hydraulic cylinder extension or timing cam travel for the full prescribed travel distance.

Cause 2: Net is narrower than the bale width — the net roll being used is not the correct width for this baler model. Confirm net roll width specification for your baler.

Cause 3: Arm travel speed is too fast — if the arm traverses the bale too quickly relative to bale rotation speed, the net spirals tightly at one end before reaching the other. Check hydraulic flow to arm cylinder against specification.

Symptom: Bale appears well-wrapped at ejection but deforms or bursts within minutes to hours as internal spring pressure splits the net.

Cause 1 (most likely): Insufficient wrap revolutions for the crop density and spring-back characteristics — straw bales, very dry hay, and high-density silage all exert higher outward pressure than standard hay. Increase wrap revolutions by 1–2 above current setting.

Cause 2: Net wrap tensile strength is insufficient for the bale density — standard hay net may not hold a high-density straw bale. Switch to a heavier-gauge net specified for high-density baling.

Cause 3: Net brake tension too low — the net is being applied without adequate tension, producing a wrap that is not taut against the bale surface. Increase net brake tension incrementally.

Symptom: Crop piles up in front of or inside the pickup rather than feeding through to the bale chamber; PTO load increases sharply; engine may lug.

Cause 1 (most likely): Crop windrow too wide or too dense for the ground speed — reduce forward speed by 20–30% or split the windrow before the next pass. The pickup can only accept crop at the rate the bale chamber can absorb it.

Cause 2: Missing or bent tines creating irregular pickup lift — inspect all tines; replace any bent by more than 10° from the original angle. A single missing tine leaves a strip of uncollected crop; a bent tine can cause a localized plug.

Cause 3: Pickup floor height is too low — tines are contacting the ground, digging soil into the crop stream and slowing the pickup rotation. Raise pickup height to keep tines 15–20mm above the ground surface during operation.

Symptom: Belts rotate faster than the bale surface; bale forms slowly or partially; visible slipping between belt inner surface and drive roller.

Cause 1 (most likely): Belt elongation has exceeded the tensioner’s compensation range — when belts stretch beyond 3–4%, the spring tensioners cannot maintain adequate belt-to-roller contact pressure. Measure all belts; replace if average elongation exceeds 2%.

Cause 2: Drive roller surface is glazed — accumulation of rubber residue from belt friction reduces the friction coefficient between belt and roller. Clean rollers with a solvent-dampened cloth; roughen the surface with coarse sandpaper if glazing is severe.

Cause 3: Belt splice failure — a belt splice that has partially separated reduces effective belt tension unevenly, causing the weakened-splice belt to slip while adjacent belts maintain tension. Inspect all splices carefully.

Symptom: Shear bolt at the PTO input hub or flywheel shears frequently — more than once per day in normal operating conditions.

Cause 1 (most likely): Wrong-grade shear bolt installed. Shear bolts have a specific grade and diameter to shear at the correct overload force — substituting a harder bolt allows overload to damage gears and shafts rather than shearing cleanly. Always use the exact grade and diameter specified in the parts manual. Shear bolt grade and diameter specifications are listed in your operator’s manual and confirmed via the dealer parts catalog for your model year.

Cause 2: Overloading the baler — windrow too dense, ground speed too high, or crop too wet for the baler’s rated capacity. Reduce load: lower ground speed, reduce windrow density, or both.

Cause 3: Debris in the crop — rocks, wire fragments, or metal objects in the windrow create instantaneous overload spikes when they enter the baler mechanism. Inspect the windrow ahead of the baler before each pass in fields with debris risk.

Symptom: Metallic grinding, regular knocking rhythm, or unusual vibration at a specific speed that was not present at the start of the season or after recent service.

Cause 1 — Grinding sound: Bearing failure. Use an infrared thermometer to identify which bearing position is running hot; any bearing more than 30°F above ambient after 10 minutes of operation is suspect. The PTO driveline bearing specifications and replacement standards are in spécifications des composants de la boîte de vitesses agricole et de la prise de force.

Cause 2 — Regular knock at specific bale rotation speed: A splice in one belt is generating an impact every time it passes over a drive or idler roller. Identify the splice position by marking each belt and observing which splice coincides with the knock timing.

Cause 3 — Vibration at PTO engagement: Drive chain elongation causing chain slap against the chain guard. Measure 12-link chain section; replace any chain exceeding 2% elongation. Also check for a loose chain guard that resonates at operating speed.