Flail Mower Gearbox T-310A — 22.1 kW Speed Reducer with 1:3 Ratio for Heavy-Duty Vegetation Shredding

T-310A Flail Mower Gearbox — 22.1 kW Speed Reducer for Agricultural Shredding

The T-310A is a 22.1 kW (30 HP) flail mower gearbox that reduces 540 RPM tractor PTO input to 180 RPM flail rotor output through a 1:3 helical gear ratio. Maximum input torque is rated at 420 Nm, producing 126 Nm (12.6 daNm) at the output shaft — the torque range needed to drive hammer-style flail blades through mixed grass, brush, and light woody stems up to 30 mm diameter.

This unit is a direct dimensional replacement for the Comer Code T-310A (type RT1000). The splined input shaft, mounting flange geometry, and output shaft profile match the original specifications, allowing a field swap on existing flail mower frames without drilling, shimming, or adapter plates. Ductile cast iron GGG40 housing material provides higher impact resistance than standard grey iron — a meaningful advantage on flail mowers where the gearbox sits exposed to debris thrown by the rotor.

At 18 kg dry weight, the T-310A is compact enough for mounting on offset and side-shift flail mowers in the 1.0 to 1.8 meter cutting-width range. Korean farms and municipal crews running Daedong, TYM, Kubota, and John Deere tractors between 30 and 45 HP use this pto gearbox for roadside vegetation control, orchard floor clearing, vineyard row maintenance, and pasture renovation where a rotary cutter would leave material too coarse for decomposition.

Technical Specifications

All parameters measured per manufacturer test protocol. Verify compatibility with your flail mower frame and tractor PTO output before ordering.

Ships dry. Add 0.8 L of 80W-90 gear oil before first use. First oil change after 50-70 operating hours.

Helical Gear Reduction in Flail Mower Applications

Why Helical Over Straight Spur for Flail Drives

The T-310A uses a helical gear pair rather than straight spur gears for its 1:3 reduction. In a helical set, the teeth are cut at an angle to the gear axis, which means multiple teeth share the load at any given moment. For a flail mower — where the rotor hits rocks, stumps, and fence wire without warning — this distributed contact pattern absorbs torque spikes across several tooth faces instead of concentrating them on a single pair. The result is measurably lower peak stress per tooth, which translates to longer gear life under the intermittent impact loads that define flail mower duty.

Speed Reduction Mechanics

At 540 RPM input, the 1:3 ratio delivers 180 RPM to the flail rotor. This speed is deliberately lower than the 700-1,400 RPM range used by rotary cutters — flail rotors depend on the mass and kinetic energy of individual swinging hammers rather than blade-tip velocity. Each hammer pivots freely on the rotor shaft, striking vegetation with its own momentum. The 180 RPM rotor speed provides enough centrifugal force to keep hammers extended during cutting while remaining slow enough for the hammers to absorb impacts without transferring destructive shock loads back through the pto gear reducer drivetrain.

GGG40 Ductile Iron Housing

Standard grey cast iron (GG25) handles compression well but fractures under sharp impact. GGG40 ductile iron — used in the T-310A housing — contains spheroidal graphite nodules instead of flake graphite, giving it roughly twice the tensile strength and three times the elongation (ductility) of grey iron. On a flail mower, the housing sits directly behind the rotor in the debris stream. A rock thrown at high velocity against a grey iron housing can cause a crack; GGG40 absorbs the same impact energy through plastic deformation without fracturing.

Where the T-310A Fits in Korean Agriculture

• ⚙ Roadside Vegetation Management — Municipal crews in Gangwon-do and Chungcheong provinces mount 1.2 to 1.5 meter flail mowers on compact tractors for clearing overgrown road shoulders. The flail rotor shreds grass and thin saplings into mulch that decomposes in place, unlike rotary cutters that leave large debris on the road surface. The 22.1 kW rating matches the 30-40 HP tractors commonly assigned to this work.
• ⚙ Orchard and Vineyard Row Clearing — Between tree and vine rows in Gyeongsang and Jeolla provinces, flail mowers with this agricultural gearbox clear groundcover and fallen prunings without disturbing root zones. The fine mulch output suppresses weed regrowth and returns organic matter to the soil — a two-for-one benefit that rotary cutters cannot match.
• ⚙ Pasture Renovation and Overseeding Prep — Before overseeding worn pasture, the flail mower cuts existing vegetation to ground level and scatters the shredded material as a thin mulch layer. The 180 RPM rotor speed keeps the hammers from scalping the soil surface — important for seed-to-soil contact during the overseeding pass that follows.
• ⚙ Ditch and Embankment Maintenance — Offset-mounted flail mowers reach down into drainage ditches and up embankment slopes at angles that rotary cutters cannot follow. The T-310A's compact 18 kg weight keeps the mower head light enough for hydraulic arm manipulation without exceeding the arm's load capacity.

Ever-Power T-310A vs. Comer T-310A — What Differs in Practice

Both gearboxes share identical mounting dimensions, shaft specifications, and power ratings. The comparison below focuses on the practical factors that affect purchasing decisions for Korean operators.

The mechanical specification — gear ratio, torque capacity, shaft dimensions, housing grade, and oil capacity — is functionally identical between both units. The Ever-Power version offers shorter lead times, lower pricing through factory-direct distribution, and Korean-language technical support.

Disclaimer: Brand names are referenced solely for cross-compatibility identification. Korea Ever-Power does not manufacture or sell Comer-branded products. All trademarks belong to their respective owners.

Maintenance Intervals and Fault Diagnosis

Lubrication Schedule

• ✔ Before first use — fill with 0.8 L of 80W-90 GL-5 gear oil through the fill plug
• ✔ 50-70 hours (break-in) — first oil drain and refill; new gears shed metal particles that contaminate fresh oil
• ✔ Every 500 hours — subsequent oil changes (or annually, whichever comes first)
• ✔ Every use — check oil level at fill plug; flail mower vibration accelerates oil consumption
• ✔ End of season — inspect input and output seals for damage; flail mower debris exposure wears seals faster than rotary cutter applications

Troubleshooting Reference

For gearbox noise and vibration troubleshooting that persists after the checks above, contact our engineering team for remote diagnostic support.

Safety Guidelines for Flail Mower PTO Operation

Flail mowers present specific hazards that differ from rotary cutters. The swinging hammers accelerate debris to high velocity, and the open discharge area below the mower deck creates a wide ejection zone. Follow these guidelines before and during operation of any pto drive gearbox connected to a flail rotor.

• ⚠ PTO guard shield must be in place — the rotating PTO shaft between tractor and gearbox must be fully enclosed by an ISO 500-compliant tubular guard at all times during operation. An exposed PTO shaft can entangle clothing in under one second.
• ⚠ Clear the cutting area — walk the path before mowing and remove rocks, metal debris, wire, and stakes. Flail hammers strike objects with enough force to send fragments over 30 meters from the mower at speeds that can cause serious injury.
• ⚠ Disengage PTO before dismounting — never leave the tractor seat with the PTO engaged. The flail rotor continues spinning for 5-10 seconds after PTO disengagement due to rotational inertia in the hammer mass.
• ⚠ Maintain all hammer bolts at specification torque — a loose hammer that detaches during operation becomes a high-energy projectile. Check hammer pivot bolt torque before each session during the first 10 hours of use, then weekly during normal operation.
• ⚠ Keep bystanders 50 meters from the discharge zone — this distance exceeds the maximum measured throw distance for typical debris ejected by flail mower rotors operating at 180 RPM with standard hammer weights.

Pair With the Right PTO Drive Components

The T-310A connects to the tractor through a pto shaft rated for at least 22.1 kW (30 HP) continuous power. For flail mower applications, select a PTO shaft with a slip clutch (not a shear bolt) for overload protection — flail rotors generate frequent torque spikes from debris impacts that would break shear bolts repeatedly during normal operation. A slip clutch absorbs these momentary peaks without interrupting work.

For farms operating rotary cutters, tillers, or spreaders alongside flail mowers, our full agricultural gearbox catalog includes bevel, planetary, and helical units across all pto gearbox categories — available with factory-direct pricing and Korean domestic delivery from our Incheon facility.

Frequently Asked Questions

Why does a flail mower use a speed reducer while a rotary cutter uses a speed increaser?
Rotary cutters depend on high blade-tip velocity for clean cutting — they need the output to spin faster than the input. Flail mowers rely on hammer mass and momentum instead. The 1:3 reduction drops speed from 540 to 180 RPM while tripling the available torque, giving each hammer enough striking force to shred heavy vegetation without stalling the rotor.

Will this gearbox fit flail mowers from brands other than Comer?
Yes, provided the mower uses the same mounting pattern and shaft dimensions as the Comer T-310A (type RT1000). Many European and Asian flail mower manufacturers use this standardized interface. Contact our team with your mower's make and model for a dimensional compatibility check.

What makes GGG40 ductile iron better than standard cast iron for flail mower gearboxes?
GGG40 has roughly twice the tensile strength and three times the elongation of standard grey cast iron (GG25). On a flail mower, the housing is exposed to high-velocity debris that can crack brittle grey iron. GGG40 deforms slightly under impact rather than fracturing — it absorbs the energy without catastrophic failure.

How often should I replace the flail hammers, and does that affect the gearbox?
Hammers typically last 200-400 hours depending on terrain. Worn hammers with uneven weight create rotor imbalance, which increases bearing loads inside the gearbox. Replace hammers in opposing pairs to maintain rotor balance and protect the pto gearbox bearings.

Can I run this gearbox on a 1000 RPM PTO?
The T-310A is rated for 540 RPM input only. At 1000 RPM, the output would reach 333 RPM — above the safe operating speed for standard flail hammer assemblies, and beyond the bearing speed rating. Contact us for 1000 RPM flail mower gearbox alternatives.

What lubricant alternatives exist for extreme cold conditions?
For winter operation below -15°C in northern Korean provinces, a 75W-90 synthetic GL-5 lubricant provides better cold-flow characteristics than the standard 80W-90 mineral oil. The synthetic blend reaches full film lubrication faster during cold starts, reducing wear during the first minutes of operation.

Operator Feedback

---

Jung Woo-jin, Road Maintenance Supervisor — Chuncheon, Gangwon-do, April 2025

"We clear 85 km of rural road shoulders each season with offset flail mowers. The Ever-Power T-310A replaced our worn Comer unit in under 30 minutes — bolt pattern matched exactly. Six months in, 380 hours logged, no issues. The GGG40 housing shrugged off a baseball-sized rock hit that would have cracked our old grey iron gearbox."

---

Hwang Soo-mi, Vineyard Manager — Yeongdong, Chungcheongbuk-do, February 2025

"Running a 1.2 meter flail mower between grape rows. The 18 kg weight keeps the hydraulic arm balanced on slopes. Oil consumption is low — only topped off once in 200 hours. Price was about 40% less than ordering the Comer replacement through our European importer."

---

Song Tae-hyun, Agricultural Contractor — Gimje, Jeollabuk-do, November 2024

"I operate three flail mowers for contract clearing across rice paddy levees. Standardized on the Ever-Power T-310A for all three machines. At this price point, keeping a spare unit on the shelf is practical — no more waiting weeks for an import when one fails mid-season."

---

Moon Ye-rin, Organic Farm Owner — Goesan, Chungcheongbuk-do, September 2024

"We use the flail mower for green manure chopping — crimson clover and hairy vetch before rice transplanting. The fine mulch from the 180 RPM rotor speed decomposes faster than what our old rotary cutter produced. Gearbox has been reliable through two planting seasons now."

---

Cho Hyun-woo, Equipment Dealer — Jeonju, Jeollabuk-do, July 2024

"Started carrying the T-310A as an affordable Comer alternative. Customer acceptance has been strong — farmers like the domestic lead time. Zero warranty returns in 12 months across 45+ units sold."