EP-55 Lawn Mower Gearbox – 50HP, 1:1.6 Ratio, 540RPM PTO Drive

★ The Most Field-Proven 50HP Right-Angle Mower Gearbox — 540RPM PTO

The EP-55 is Korea Ever-Power’s rotary mower gearbox built for tractors in the 40–55HP range. A 1:1.6 speed ratio and gear module 6.0 handle the shock-loads of pasture, roadside, and orchard mowing without the tooth-fatigue that plagues fine-pitch alternatives. The 1 3/8″ Z6 spline input (ISO 500) connects directly to Daedong, LS Mtron, TYM, Kubota, and Yanmar PTO shafts — no adapters. Cone-base spline shaft output matches European mower deck standards. Every unit is 100% load-tested before shipping. A proven replacement for comparable Comer and Bondioli models in the 50HP / 1:1.6 class.

Category: Lawn Mower Gearboxes

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Additional information

EP-55 Lawn Mower Gearbox — 50HP Right-Angle PTO Drive

EP-55 lawn mower gearbox 50HP right angle PTO drive Korea Ever-Power

EP-55 · 50HP · Ratio 1:1.6 · 28.7 kg

The EP-55 lawn mower gearbox is a right-angle bevel-gear drive unit designed for rotary mowers, brush cutters, and pasture management equipment requiring up to 50HP at 540RPM PTO input. With a 1:1.6 speed ratio and gear module 6.0, it converts tractor PTO rotation into high-torque blade output through a 15/24-tooth bevel gear pair, delivering the blade-tip velocity needed for clean, consistent cutting across grass, light brush, and roadside vegetation.

The housing is cast from nodular cast iron (ductile iron, GGG50 grade) — the same material specification used in heavy industrial gear drives. This gives the EP-55 a toughness-to-weight ratio that outperforms standard grey iron housings found on budget mower gearboxes: when a blade strikes a buried stone at full speed, the GGG50 wall flex-absorbs the energy rather than cracking. The input shaft accepts the industry-standard 1 3/8″ Z6 spline (ISO 500), while the output terminates in a cone-base aequilate spline shaft — the preferred interface on European and Asian rotary mower decks.

At 28.7 kg net weight, the EP-55 sits in the mid-range of the 50HP segment — substantial enough to absorb shock loads from field debris, yet light enough for single-person installation on 3-point linkage mowers. Every unit undergoes full-load bench testing before dispatch. Korea Ever-Power supplies the EP-55 to agricultural machinery dealers, OEM mower manufacturers, and maintenance workshops across South Korea, Japan, Vietnam, Thailand, Malaysia, and the wider Asia-Pacific region.

Replacement Reference: The EP-55 is engineered as a direct-specification replacement for comparable Comer Industries and Bondioli & Pavesi lawn mower gearbox models in the 50HP / 1:1.6 class. Korea Ever-Power is not affiliated with, sponsored by, or a distributor of these brands. Model references are provided solely to assist customers in identifying compatible specifications.

Technical Specifications & Dimensional Data

The table below lists the factory-verified parameters for the EP-55 agricultural mower gearbox. All figures are drawn directly from the manufacturer's official product datasheet. Module 6.0 denotes a coarse tooth pitch — a deliberate choice for shock-load environments where fine-pitch gearing risks tooth fatigue. The 15/24 tooth count achieves the 1:1.6 ratio while avoiding the resonance-frequency issues common in symmetrical 1:1.5 gearsets under continuous field operation.

EP-HC-55 Lawn Mower Gearbox Dimension

Parameter	Value	Technical Notes
Model	EP-55	Lawn Mower Series — cast iron, red powder coat
Speed Ratio	1 : 1.6	Speed increaser — output rotates faster than input
Teeth Count	15 / 24	Pinion / Crown gear
Gear Module	6.0	Coarse pitch — optimal for shock-load resistance
Rated Power	50 HP	≈ 37.3 kW continuous duty rating
Rated Input Speed	540 RPM	Standard agricultural tractor PTO speed
Input Shaft	1 3/8″ Z6 spline	ISO 500 / ASABE S205.7 universal standard
Output Shaft	Cone-base aequilate spline	Standard European/Asian mower deck interface
Housing Material	Nodular cast iron (GGG50)	High toughness, excellent vibration damping
Net Weight	28.7 kg	Excluding PTO shaft and blade hub
Dimensions (approx.)	221 × 178 × 115.5 mm	L × H × W per engineering drawing

agricultural gearbox features 1

Internal bevel gear and bearing arrangement

Looking at the cross-section above, three design elements stand out. The housing wall thickness is consistent at all load-bearing faces — unlike some cast housings that thin out at the corners to save weight, creating stress-concentration points. The bearing seats are machined to H7 tolerance on both input and output sides, ensuring the bevel gear mesh stays within the designed tooth contact zone under load. The oil drain sits at the lowest point of the housing in all standard mounting orientations, meaning a gravity drain removes all used oil without residue.

The gear module of 6.0 means each tooth is 6 mm in pitch — visible in the image as the clearly separated, robust tooth profile. This coarse pitch carries higher bending loads per tooth than the M4–M5 gearing found on lighter mower units, directly translating to the EP-55's ability to handle the abrupt torque spikes that occur when blades contact buried obstacles at full rotational speed.

How the EP-55 Bevel Gear Drive Works

Understanding the mechanical logic behind this PTO gearbox helps you get the most from it and diagnose early warning signs before they become costly failures. Power travels through four sequential stages:

① PTO Input & Primary Drive

The 540 RPM tractor PTO shaft slots directly into the 1 3/8″ Z6 spline socket. Spline engagement transmits torque without backlash from the instant the PTO clutch engages. The input shaft runs on a deep-groove ball bearing at the front and a cylindrical roller bearing at the inner housing wall, managing radial load from the bevel pinion and axial thrust from gear mesh simultaneously.

② Bevel Gear Mesh & Speed Change

The 15-tooth drive pinion meshes with the 24-tooth crown gear at 90°, converting horizontal PTO rotation to vertical blade-drive rotation. The 15:24 ratio steps output speed up 1.6× — so 540 RPM input becomes 864 RPM at the blade hub. Both gear faces are carburised to 0.8–1.2 mm case depth and quench-hardened to HRC 58–62, resisting pitting and micro-spalling under sustained field loads.

③ Output Shaft & Blade Coupling

The output terminates in a cone-base aequilate spline shaft — the standard for European rotary mower decks and blade hubs. The taper self-centres the blade hub at assembly, providing repeatable concentricity and eliminating vibration from hub float. Double-lip NBR oil seals on both shaft ends keep gear oil in and field contamination out throughout the service life.

④ Lubrication & Thermal Management

Splash-lubricated with SAE 90 gear oil (GL-4 or GL-5). Fill to the centre of the sight glass — approximately 350–400 ml. Drain and refill at 50 hours (break-in), then every 200 hours. The nodular iron housing dissipates heat more efficiently than sheet-steel alternatives, keeping oil temperature stable during extended mowing runs in warm climates.

The combined result of these four stages — direct PTO coupling, hardened bevel mesh, tapered spline output, and sealed splash lubrication — is a rotary mower gearbox built to handle continuous full-load operation with minimal maintenance between service intervals.

Six Reasons This Gearbox Handles Seasons, Not Just Sessions

🏗️

Nodular Cast Iron Housing (GGG50)

GGG50 ductile iron absorbs impact energy 3–4× better than grey iron. When a blade strikes a buried stone, the housing flex-absorbs the shock rather than cracking — a critical difference during full-speed field operation where impacts are unpredictable.

⚙️

Quench-Hardened Gear Faces (HRC 58–62)

Both bevel gears are carburised to 0.8–1.2 mm case depth and quench-hardened to HRC 58–62. This surface hardness resists pitting and micro-spalling under repetitive load cycles, extending tooth life well beyond standard induction-hardened gears used in lower-cost alternatives.

🔒

Double-Lip NBR Oil Seals

High-quality NBR double-lip seals on both shaft ends prevent oil seepage even at slopes up to 30°. The secondary lip acts as a dust wiper, keeping grit out of the bearing race — a common entry point for premature wear on budget gearboxes used in dry or dusty field conditions.

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100% Factory Load Test

Every EP-55 is run under full rated load on a calibrated test bench before packing. This catches assembly defects, bearing pre-load errors, and gear-mesh misalignment that visual inspection cannot detect — so you receive a verified working unit, not a production-line sample that was never run.

🔌

ISO 500 Universal PTO Interface

The 1 3/8″ Z6 input spline conforms to ISO 500 / ASABE S205.7. Direct fit with any standard agricultural tractor PTO shaft — compatible with Daedong/Kioti, LS Mtron, TYM, Kukje, Kubota, Yanmar, John Deere, and New Holland in the 40–60HP range. No adapters or machining required.

🚢

Fast Asia-Pacific Dispatch (3–7 Days)

Korea Ever-Power maintains stock inventory for HC series units, enabling short lead times for buyers in South Korea, Japan, Vietnam, Thailand, Indonesia, Malaysia, and the Philippines. Bulk OEM orders are quoted individually with dedicated production slots.

Tractor Compatibility & Model Selection Guide

Choosing the right lawn mower gearbox starts with three numbers: your tractor's PTO horsepower, your mower's cutting width, and the PTO shaft speed. The EP-55 covers a well-defined operating range — use the matrix below to confirm fit, or contact our team for personalised recommendations.

Tractor PTO HP	Cutting Width	Recommended Model	Typical Application
20–30 HP	1.2 – 1.5 m	EP-LF211 / EP-RC30	Compact tractors, orchard alleys
30–40 HP	1.5 – 1.8 m	EP-RC31 series	Mid-range mowers, roadside maintenance
40–55 HP	1.8 – 2.2 m	✔ EP-55 <— You are here	Pasture, sports fields, roadside strips
55–70 HP	2.0 – 2.5 m	EP-RC61 (60HP)	Commercial mowing, tough pasture
70–90 HP	2.2 – 3.0 m	EP-RC81 (80HP)	Large-scale operations, heavy brush

Three things to confirm before ordering:

1. PTO Speed
Confirm your tractor's live PTO runs at 540 RPM — not 1000 RPM. The EP-55 is rated specifically for 540 RPM input.
2. Input Shaft Size
Verify the PTO drive shaft is 1 3/8″ Z6 spline. Most 40–60HP tractors use this standard; older models may differ.
3. Mower Deck Interface
Check the existing output termination — the EP-55 uses a cone-base spline shaft. If your deck uses a plain round bore, contact us for coupling adapters.

Where the EP-55 Works Best — Field Applications

The 50HP rating and 1:1.6 ratio of this agricultural gearbox place it at the centre of a wide band of practical mowing applications across Korea, Japan, and Southeast Asia.

🌿 Pasture & Grassland Management — Korea & Northern Japan

Livestock pastures in South Korea's Jeollabuk-do and Gangwon-do provinces, and northern Japan's Hokkaido region, typically require mowing cycles two to four times per season at cutting heights of 80–150 mm. The EP-55's 50HP rating handles dense, mature grass on 1.8–2.2 m deck widths without overloading — a common failure scenario when underpowered gearboxes are pushed by high-blade-speed settings. The 1:1.6 ratio delivers approximately 85 m/s blade tip speed at a standard 500 mm blade radius, sufficient for a clean cut rather than the tearing action seen with low-speed blades.

🚧 Roadside & Embankment Maintenance — National & Provincial Roads

Highway maintenance contractors and municipal road departments across Korea and Southeast Asia run PTO-driven rotary mowers on tractor-mounted configurations for roadside strip management. These operations involve uneven terrain, concealed stones, and intermittent heavy-grass patches — all high shock-load scenarios. The nodular iron housing and hardened gear faces make the EP-55 a preferred choice for contractors who cannot afford mid-season gearbox failures on active road contracts.

⚽ Sports Field & Turf Renovation — Korea & Japan

Soccer pitches, school grounds, and golf course rough areas require seasonal scarification and heavy mowing. The precision of the 1:1.6 ratio delivers consistent blade tip speed that produces uniform cut height without scalping. At 28.7 kg, the gearbox adds controlled mass to the mower deck, reducing bounce on the firm, compacted turf typical of Korean school and municipal sports grounds.

🍎 Orchard & Vineyard Floor Management — Japan, Korea, Vietnam

In apple, pear, and citrus orchards across Japan's Tohoku region, Korea's Chungcheong provinces, and northern Vietnam's highland growing areas, growers use compact tractor-mounted rotary mowers to manage floor cover between tree rows. The EP-55's compact mounting footprint (221 mm longest dimension) fits the narrower deck designs used in orchard work, while 50HP provides margin for the thick-vegetation patches found under drip-irrigated tree lines.

🌾 Cover Crop Termination Before Planting — Rice & Grain Regions

Before planting rice, vegetables, or grain crops, many Korean and Japanese farmers use rotary mowers to knock down and incorporate cover crops (rye, vetch, clover) prior to tillage. The EP-55's rated power matches the 40–55HP compact tractors typical on 1–5 ha plots in these markets. Using a lawn mower gearbox properly rated for the job prevents the chronic overheating that shortens the life of under-specified units.

EP-55 lawn mower gearbox application in pasture and field mowing across Asia Pacific

Korea Ever-Power EP-55 vs. Comparable Imported Gearboxes

Many buyers in Korea and Southeast Asia have traditionally sourced replacement mower gearboxes from European catalogue brands. The comparison below is based on publicly available product data and typical landed-cost structures to help you make a practical purchasing decision.

Comparison Point	Korea Ever-Power EP-55	Typical European Equivalent
Power Rating	50 HP	50 HP (comparable class)
Housing Material	Nodular cast iron GGG50	Typically nodular or grey iron
Gear Treatment	Carburised & quench-hardened	Hardened (process varies)
Unit Price (approx.)	Competitive — contact us	30–60% higher landed cost in Korea
Lead Time to Korea	3–7 business days	4–8 weeks (sea freight)
Minimum Order	1 unit (spares); OEM MOQ on request	5–10 units min. via distributor
Custom / OEM Options	Available — shaft, ratio, colour	Factory-only; limited channel access

Disclaimer: Korea Ever-Power Agricultural Machinery Co., Ltd. is not affiliated with, sponsored by, or an authorised distributor of Comer Industries S.r.l., Bondioli & Pavesi S.p.A., or any other brand referenced herein. Comparisons are provided as neutral purchasing reference only and do not imply any competitive or counterfeit relationship.

Why Agricultural Machinery Buyers Choose Korea Ever-Power

agricultural gearbox workshop 1

Production facility — 3,800 m² dedicated gear manufacturing floor

Korea Ever-Power Agricultural Machinery Co., Ltd. is the Asia-Pacific supply and distribution partner for precision-manufactured agricultural gearboxes from a manufacturer with 19 continuous years of gear production. Our manufacturing base occupies 3,800 m² of dedicated floor space, employs 90 skilled technicians and engineers, and operates annual output capacity exceeding RMB 40 million.

The quality management process covers every production stage: incoming raw material verification, gear hobbing and grinding to ISO 1328 tolerance class 6–7, carburising and quench-hardening in controlled-atmosphere furnaces, precision assembly with pre-loaded bearings, and 100% final load testing on calibrated bench rigs. More than 95% of production is exported to Europe, North America, Australia, and across Asia — a track record that reflects sustained customer confidence in product consistency.

✔ 19 years of agricultural gear manufacturing (established 2006)
✔ 3,800 m² dedicated production facility with CNC gear machining
✔ 90 professional engineers and production staff
✔ ISO-compliant workflow — 100% load-tested before dispatch
✔ >95% of production exported globally — Europe, USA, Australia, Asia
✔ OEM and custom specifications accepted (ratio, shaft size, housing colour)
✔ Regional stock for fast Asia-Pacific dispatch — 3–7 business days to Korea, Japan, SEA

Complete Your Drive System — Accessories & Compatible Products

A mower gearbox delivers full value only when matched with the right surrounding components. The following products are commonly ordered alongside the EP-55 by Korea Ever-Power customers building or rebuilding complete rotary mower drive systems.

Agricultural gearbox accessories including PTO drive shafts and complementary drive components

🔩 PTO Drive Shafts

The link between your tractor and the EP-55. We supply cross-joint PTO drive shafts in standard lengths from 500–1,500 mm, with safety guards, slip clutches, and overrunning clutch options. Sized for 1 3/8″ Z6 input — direct fit with the EP-55.

→ cvjointdriveshaft.com

⚙️ Worm Gear Reducers

For secondary reduction stages — such as slow-speed conveyor drives on harvesting rigs or seed-drill metering systems — our range of worm gear reducers provides ratios from 5:1 to 80:1 in compact right-angle housings.

→ worm-reducers.xyz

🌾 More Lawn Mower Gearboxes

If the EP-55 doesn't match your power or ratio requirement, browse the full range of lawn mower gearboxes — from 20HP light-duty units to 80HP heavy-duty models — plus rotary cultivator, round baler, and fertiliser spreader gearboxes.

→ agriculturalgear-boxes.com

What Our Customers Say

Kim Jae-won Farm Equipment Dealer · Gyeonggi Province, South Korea · 2024

We've stocked the EP-55 for about a year and it's now one of our top sellers in the 50HP segment. Before we switched, we were selling a European equivalent that cost about 40% more landed. Our customers — mostly rice and orchard farmers running 45–55HP Korean tractors — haven't flagged any quality issues. Three units came back for inspection; all turned out to be installation errors, not product faults.

Tanaka Hiroshi Agricultural Contractor · Niigata Prefecture, Japan · 2024

I manage roadside mowing contracts for about 120 km of national highway in Niigata. The work is hard on gearboxes — lots of hidden stones, wet grass after rain, 8-hour days in peak season. The EP-55 has been on one machine for two full seasons now with no issues beyond the standard 200-hour oil change. The nodular iron housing feels noticeably stiffer than the grey iron casting I replaced.

Nguyen Thi Lan Agri-Machinery Importer · Ho Chi Minh City, Vietnam · early 2025

Our customers buy for sugar cane edge mowing and cover crop management before the dry season. The 28.7 kg weight is a plus — we replaced cast alloy units that cracked after one season in the heat and humidity. Zero warranty claims on the EP-55 so far. Delivery was 6 days from order to our warehouse in HCMC. Good communication throughout.

Park Sung-min Municipal Parks Department · Daejeon, South Korea · 2024

We maintain 14 sports grounds and around 40 km of green corridor in Daejeon. After a two-month trial we ordered five more. The noise level is noticeably lower than our old gearboxes, even after 300 hours of use. Oil seals held perfectly across all units — not a single drop of leakage. For a public works team, consistent quality across a batch matters more than any single feature.

Sombat Charoenwong Orchard Equipment Supplier · Chiang Mai, Thailand · 2025

Selling into the longan and lychee orchard market here. Farmers need something that fits their 50HP tractors and handles thick grass under trees without overheating. I ordered 10 initially, sold them in six weeks, and placed a second order for 20. Price is right, documentation complete for customs, and packaging survived sea freight without damage.

Müller Rainer Equipment Exporter · Seoul (European re-distribution) · 2024

We source for mid-Eastern European markets where price sensitivity is high. The EP-55 passes all mechanical checks our engineers run — tooth contact pattern, bearing pre-load, oil seal integrity. It's not identical to a premium European brand, but for a 35–40% price difference the performance is well within our acceptance spec. We've placed three container orders and will continue.

Frequently Asked Questions

What does the 1:1.6 ratio mean — is the EP-55 a speed increaser or reducer?

The EP-55 is a speed increaser. For every one revolution at the PTO input shaft, the output shaft turns 1.6 times. At 540 RPM input, the blade-drive output rotates at approximately 864 RPM — the stepped-up speed that produces clean mowing blade tip velocity. A ratio below 1:1 would be a reducer, which is the opposite and unsuitable for rotary mowing.

Is the EP-55 compatible with Daedong (Kioti), LS Mtron, or TYM tractors?

Yes, provided the tractor's PTO runs at 540 RPM and uses a 1 3/8″ Z6 spline. The major Korean brands — Daedong/Kioti, LS Mtron, TYM, and Kukje — use ISO 500-compliant PTO shafts in the 40–60 HP range. Check your operator manual under "PTO specifications" to confirm shaft size and speed.

What gear oil does the EP-55 use and how often should it be changed?

Use SAE 90 gear oil, GL-4 or GL-5 spec. Fill to the centre mark of the oil level plug — approximately 350–400 ml. Change at 50 hours for break-in, then every 200 operating hours. In climates above 35°C, reduce the interval to 150 hours. Water in the drain oil indicates a seal failure requiring immediate attention.

Can the EP-55 replace my existing Comer or Bondioli mower gearbox?

In most cases yes — if the original is also around 50HP, 1:1.6 ratio, 540 RPM input, with cone-base spline output. Verify three dimensions: input spline (1 3/8″ Z6), output shaft interface (cone spline taper), and mounting bolt pattern. Send us the model number or a photo and we'll confirm compatibility before you order.

My gearbox is making a grinding noise after 300 hours — gears or bearings?

Gradual grinding typically points to bearing wear on the input shaft. A high-pitched squeal suggests seal failure and dry running. A sudden metallic knock during engagement usually signals a gear tooth fracture. Diagnose by draining the oil: fine grey particles indicate bearing wear; large silvery chips indicate gear tooth damage. Contact our technical team with a description for rebuild vs. replacement advice.

What is the difference between the EP-55 and the EP-RC31 series?

The EP-55 is 50HP with a fixed 1:1.6 ratio. The EP-RC31 series is rated 30–40HP and comes in three ratio variants (1:1.47, 1:1.93, and dual-ratio). Choose the EP-55 for tractors in the 45–55HP range with wider mower decks (1.8–2.2 m); choose the EP-RC31 for more compact setups where lower power is sufficient and multi-ratio flexibility is valued.

Do you offer OEM supply for mower manufacturers in Korea or Japan?

Yes. Korea Ever-Power accepts OEM specifications: modified shaft dimensions, alternative gear ratios, custom housing colours, and private-label marking. MOQ is negotiated per specification. First-article sample lead times are typically 25–35 days; production runs follow in 30–45 days. Contact us with a technical drawing or specification sheet.

How do I prevent premature oil seal failure?

Three common causes: over-filling (excess pressure blows the seal — fill only to the mark), PTO shaft misalignment above 15° (creates side-load on the input seal), and continuing to run after a seal has begun to weep. At every 200-hour service, wipe the shaft areas clean and check for oil film around the seal lips before refilling.

What are the shipping options to South Korea, Japan, and Southeast Asia?

For 1–5 units: DHL, FedEx, or EMS courier — 3–5 business days to Korea and Japan. For 10+ units: sea freight LCL — 10–18 days to Busan, Yokohama, or Ho Chi Minh City. We handle all export documentation. Certificate of Origin and test reports are available on request for customs clearance in Korea, Japan, and ASEAN countries.

What warranty does the EP-55 carry?

12 months from dispatch against manufacturing defects in materials and workmanship. Covers housing fracture under rated loads, gear tooth failure within rated HP, bearing failure not caused by contamination or oil starvation, and seal defects present at delivery. Not covered: impact damage from foreign objects, over-speed operation, incorrect installation, or oil neglect. To claim, contact us with the unit serial number and a description of the failure.

Additional information

Editor	Cxm