Pull-behind Mower Gearbox EP-GC325 | 160HP Trailing PTO

EP-GC325 — Heavy-Duty Trailing Mower Gearbox for Commercial Mowing

The EP-GC325 is built for commercial mowing operations that demand sustained high power delivery. Unlike compact implement gearboxes that sacrifice power capacity for weight savings, the EP-GC325 handles 160 HP through a 1:1 direct-drive ratio — passing full 540 RPM PTO power directly to the cutting mechanism without speed reduction or multiplication. This PTO gearbox configuration delivers maximum available tractor power to the mower's cutting discs, enabling aggressive cutting through dense vegetation, wet grass, and overgrown pasture that lighter mowing equipment cannot handle.

The 1400 Nm output torque at 540 RPM provides the sustained cutting force required by wide-format trailing mowers operating at forward speeds of 8-15 km/h. The Gleason helical tooth profile distributes this substantial torque load across a wider gear contact area than straight bevel alternatives, reducing tooth surface stress and extending gear life under the continuous duty cycles that commercial mowing operations demand — 6-10 hour daily shifts during the Korean growing season (April through October).

The EP-GC325 pairs directly with the EP-GCYB series trailing mower cutter bars: the 6-disc EP-GCYB06 (2.5 meter working width, 50 HP requirement) and the 7-disc EP-GCYB07 (3.0 meter working width, 90 HP requirement). Both cutter bars spin their discs at 3000 RPM through an internal gear train driven by the EP-GC325's 540 RPM output. Korean golf courses, sports facilities, municipal parks departments, and large-scale agricultural gearbox pasture operations use this trailing mower system for professional-grade vegetation management.

Technical Specifications

EP-GC325 Gearbox Specifications

EP-GCYB Series Cutter Bar Specifications

Key Performance Advantages

1:1 Direct Drive vs. Reduction Gearbox — When Each Configuration Applies

Trailing mowers can use either 1:1 direct-drive gearboxes (like the EP-GC325) or reduction gearboxes. The choice depends on the cutter bar's internal gear train design and the intended application intensity.

The EP-GC325's 1:1 direct drive is the correct choice for disc-type cutter bars (like the EP-GCYB series) where the cutter bar's internal gear train handles the final speed multiplication from 540 RPM to the 3000 RPM disc speed. The gearbox's job in this system is power redirection (horizontal-to-vertical) and torque transmission — not speed change. Reduction gearboxes serve flail-type mowers where the gearbox itself must provide the speed reduction that the simpler flail mechanism does not include internally.

Application Selection Guide by Venue Type

Korean Commercial Mowing Applications

• ◆ Golf Course Fairway Maintenance — Korea operates over 500 golf courses requiring year-round fairway and rough management. The EP-GCYB07 cutter bar's 3.0 meter width covers fairway mowing efficiently at 10-15 km/h forward speed, completing a typical 18-hole fairway circuit in 4-5 hours. The EP-GC325 pto gearbox delivers the sustained 90 HP the 7-disc cutter bar requires for clean cutting in Korean Bermuda grass and Zoysia grass varieties that dominate local courses.
• ◆ Municipal Parks and Public Green Spaces — Korean municipal governments manage extensive park systems in cities like Seoul, Busan, Daejeon, and Daegu. The EP-GC325 trailing mower system provides the commercial-grade cutting capacity needed to maintain 10-30 hectare park complexes on weekly mowing schedules during the April-October growing season. The Gleason helical gearbox operation produces lower noise levels than straight-bevel alternatives — an important consideration for park mowing near residential neighborhoods.
• ◆ Livestock Pasture Management — Korean beef and dairy operations in Gangwon-do and Jeju-do manage large pasture areas requiring regular mowing to maintain grass quality and prevent weed establishment. The EP-GC325's 160 HP capacity handles the heavy cutting loads encountered in Korean pasture conditions — mixed grass stands with occasional woody weed growth that requires sustained high torque to cut cleanly. The agricultural gearbox trailing configuration allows the mower to follow ground contours independently of the tractor, important on the hilly terrain typical of Korean pasture land.

Troubleshooting Common Issues

• ☑ Uneven Cut Quality Across Mower Width — If one side of the cut strip is consistently higher than the other, the trailing mower cutter bar is not level. Check the hitch height adjustment and the mower's leveling mechanism. The EP-GC325 gearbox itself does not affect cut height — it only transmits power. Uneven cutting is always a cutter bar alignment or ground-following issue, not a gearbox problem.
• ☑ Gearbox Overheating During Extended Operation — The EP-GC325 is rated for continuous duty, but extended operation above 120 HP in ambient temperatures exceeding 35C can cause oil temperature to rise above the recommended range. Verify oil level is at specification (low oil reduces cooling capacity). If overheating persists at correct oil level, check the gearbox breather for blockage — a pressurized housing retains heat. Consider synthetic 75W-90 oil for Korean summer operations where ambient temperatures regularly exceed 33C.
• ☑ PTO Shaft Shear Bolt Failures — Repeated shear bolt failures on the PTO shaft indicate the mower is encountering obstructions that produce torque spikes exceeding the protection threshold. This is common during first-season mowing of previously unmaintained areas. Walk the mowing area before operation to remove rocks, metal debris, and woody stumps that cause sudden blade stops. If the shear bolt rating matches the gearbox specification and failures continue, the cutting area contains embedded obstructions that require clearance before mowing.
• ☑ Vibration Increase Over Time — Gradually increasing vibration typically indicates worn or damaged cutting blades creating imbalance in the cutter bar rather than a gearbox fault. Inspect all cutting blades for uniform condition — a single damaged or missing blade creates imbalance that transmits vibration through the cutter bar to the gearbox. Replace blades in matched sets to maintain disc balance.
• ☑ Oil Leak at the Gearbox-to-Cutter-Bar Interface — The seal between the EP-GC325 output shaft and the cutter bar input requires proper alignment during installation. Misalignment creates an eccentric load on the seal lip, causing premature wear and leakage. Remove and reinstall the gearbox, verifying the output shaft enters the cutter bar input bearing squarely. Apply assembly paste to the shaft splines during reinstallation to indicate contact pattern — full, even contact confirms proper alignment.

Complete the Mowing System

Connect the EP-GC325 to the tractor through a pto shaft rated for the tractor's actual PTO output (up to 160 HP maximum). For trailing mower applications, the PTO shaft must accommodate the variable distance between tractor PTO and mower gearbox as the trailing mower follows ground contours. Select a telescoping PTO shaft with adequate extension range for your hitch configuration.

Browse our full agricultural gearbox range including disc mower gearboxes, rotary cutter drives, and application-specific models for different mowing equipment types.

Frequently Asked Questions

Why does the EP-GC325 use a 1:1 ratio instead of a speed increase for faster cutting?
The EP-GCYB series cutter bars contain their own internal gear train that multiplies the EP-GC325's 540 RPM output to 3000 RPM at the cutting discs. Adding another speed multiplication in the main gearbox would produce excessive disc speed, increase blade wear, and create dangerous projectile risk from thrown debris. The EP-GC325's 1:1 ratio delivers maximum power to the cutter bar's internal gear train, which then handles the final speed multiplication to the appropriate disc speed.

Can I use the EP-GC325 with cutter bars from other manufacturers?
The EP-GC325's output shaft interface is designed for the EP-GCYB series cutter bars. Compatibility with third-party cutter bars depends on matching the output shaft spline profile, mounting bolt pattern, and housing interface dimensions. Contact our technical team with your cutter bar specifications for compatibility verification.

What tractor class is recommended for the EP-GCYB07 (3.0m) cutter bar?
The EP-GCYB07 requires 90 HP minimum at the PTO. Korean tractors in the 100-120 HP class (John Deere 6120M, Kubota M7060, New Holland T6.145) provide adequate power with reserve for the 3.0 meter cutter bar. Using a tractor below the 90 HP minimum causes the mower to bog down in dense grass, producing uneven cut quality and excessive strain on the gearbox.

How often should cutting blades be replaced?
In typical Korean turf conditions, cutting blades last 200-400 operating hours depending on ground conditions and debris exposure. Sandy soils accelerate blade wear significantly. Inspect blades every 50 hours and replace when blade length has worn to less than 75% of original length or when edge damage prevents clean cutting. Always replace blades in complete sets (all 12 or 14) to maintain disc balance.

Is the EP-GC325 suitable for rough-terrain mowing?
Yes — the trailing configuration allows the mower to follow ground contours independently of the tractor, accommodating terrain undulation that mounted mowers cannot handle. However, the disc-type cutting system is designed for grass and light vegetation, not brush or woody growth exceeding 20mm stem diameter. For rough terrain with woody vegetation, consider a flail-type mowing system instead.

What Korean Mowing Professionals Report

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Cho Hyeon-woo, Golf Course Superintendent — Yongin, Gyeonggi-do, August 2025

"Run the EP-GC325 with the EP-GCYB07 cutter bar on our 36-hole golf course fairways. Mow 45 hectares of fairway twice weekly during peak season. The gearbox handles 8-hour shifts at 90+ HP without temperature issues. Noise level is noticeably lower than the Italian mower gearbox we replaced — the greenkeepers working on adjacent holes appreciate the reduced disturbance."

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Park Eun-seo, Municipal Parks Department — Daejeon, September 2025

"Our parks department maintains 28 hectares of public green space across 12 locations. The EP-GC325 trailing mower covers our largest park (8 hectares) in a single morning. The 3.0 meter cut width and 12 km/h forward speed productivity exceeds what we could achieve with three smaller mowers and three operators. Labor cost reduction paid for the equipment in two seasons."

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Lee Chang-ho, Livestock Farm — Pyeongchang, Gangwon-do, July 2025

"Manage 60 hectares of beef cattle pasture on hilly terrain. The trailing mower follows the contours that a rear-mounted mower cannot handle. The EP-GC325's 160 HP headroom means I never worry about overloading the gearbox when the mower hits a dense weed patch on a hillside. Replaced the blade set once in 350 hours — reasonable for our rocky soil conditions."

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Na Yeon-ji, Sports Facility Manager — Chuncheon, Gangwon-do, June 2025

"Our multi-sport complex has 4 soccer fields and 2 rugby fields requiring weekly mowing April through November. The EP-GCYB06 (2.5m) cutter bar handles all 6 fields in one day. Cut quality is consistent across the full 8-hour shift — no deterioration late in the day like we experienced with our previous smaller mower that was running at its power limit."

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Bae Sung-min, Road Maintenance Contractor — Cheongju, Chungcheongbuk-do, May 2025

"Contract highway verge mowing for 180 km of national highway shoulders in Chungcheongbuk-do. The EP-GC325 trailing mower handles the 10 km/h forward speed the road authority requires, and the 2.5m width covers the verge in a single pass. The gearbox runs 6-8 hours daily through the 7-month mowing season without any service issues beyond routine oil changes."