Pull-Behind Mower PTO Gearbox | Replaces Comer T-279D

Product Overview

The EP-GC281 is a trailing mower PTO gearbox designed for pull-behind (trailed) disc mower assemblies — the large-format mowing systems that connect to the tractor's drawbar rather than the 3-point hitch. These machines cut wider swaths (2.4 m to 3.5 m+) at higher travel speeds than mounted mowers, and their gearboxes must handle correspondingly higher power levels. The EP-GC281 delivers 85 kW (114 HP) continuous input capacity through a 1:1 Gleason helical bevel gear set, producing 1,400 Nm of output torque at 540 RPM — enough to drive the full cutter bar assembly at operating speed without power loss. For operators who also need standalone gearboxes, our agricultural gearbox covers 400+ replacement models.

This PTO gearbox replaces the Comer Industries T-279D with matching shaft dimensions, mounting geometry, and torque capacity. The cast iron housing is engineered for the vibration and dust environment of high-speed field mowing, and the Gleason helical tooth profile runs quieter and smoother than straight bevel alternatives — reducing operator fatigue during 8-10 hour mowing shifts.

Specifications and Dimensions

Gleason Helical Bevel Gear Technology

The EP-GC281 uses Gleason-type helical spiral bevel gears rather than the straight bevel gears found in most agricultural PTO gearbox units. The difference matters in trailing mower service for three reasons. First, the curved tooth contact pattern in helical gears engages gradually rather than all at once — reducing the impulse noise and vibration that straight bevel gears produce at high rotational loads. Second, the load-bearing contact area on helical teeth is larger than on straight teeth of the same module, which increases the torque capacity for a given gear size. Third, the gradual engagement produces smoother power transmission, reducing the cyclic torsional spikes that accelerate bearing fatigue in high-duty-cycle mowing applications where the PTO gearbox runs at full load for hours at a time.

Applications

Trailed Disc Mower Systems

The primary application is driving the cutter bar on large trailing disc mowers used for hay and forage production. These mowers connect to the tractor drawbar and run a PTO driveshaft back to the PTO gearbox mounted on the mower frame. The 1:1 ratio passes full PTO speed (540 RPM) to the cutter bar input, which then uses its own internal gear train to drive individual disc modules at 2,500-3,000 RPM. Browse all available models at our PTO gearbox product range.

Mower-Conditioner Combinations

Some trailing mower-conditioner machines (which cut and crimp forage in a single pass) use a gearbox in this power class to drive both the cutter bar and the conditioning rollers. The 85 kW capacity and 1,400 Nm torque handle the combined load of disc cutting and crop conditioning without oversizing the tractor requirement.

Large-Scale Forage Operations

Korean forage producers serving the dairy cattle industry harvest ryegrass, timothy, and alfalfa across 20-100+ hectare operations. Trailing disc mowers with this PTO gearbox cut 2-3 times per season at travel speeds of 8-15 km/h, covering significantly more ground per hour than mounted mowers. The 85 kW capacity ensures the cutter bar receives full power even at high travel speeds in dense, mature forage stands where the cutting resistance per metre of working width is at its peak.

PTO Shaft and Companion Products

Trailing mowers run longer PTO driveshafts than 3-point hitch machines — often 1.5 to 2.5 metres between tractor PTO stub and gearbox input — and the shaft must accommodate the angular changes that occur as the trailed mower tracks across uneven ground. Wide-angle universal joints (up to 80 degrees working angle) and adequate shaft guard coverage are non-negotiable safety and durability requirements for this configuration. Korea Ever-Power manufactures heavy-duty PTO shaft assemblies specifically designed for trailing implement service, with the extended length options and wide-angle joints that pull-behind mowers need.

We also supply the EP-GT series trailing mower cutter bar assemblies that pair with the EP-GC281 gearbox, available in working widths from 2.4 m to 3.5 m. Contact our technical team for complete mower system packages including gearbox, cutter bar, PTO shaft, and spare blade sets — shipped as a single coordinated order.

Operating Tips for Trailing Mower Gearboxes

Trailing mower PTO gearbox units operate under different conditions than 3-point hitch mower gearboxes. The longer driveshaft introduces more angular variation as the mower tracks over uneven terrain, which changes the loading pattern on the gearbox input bearing. Check oil level before every mowing session — even a small seal leak on a trailing mower can drain the reservoir faster than expected because the gearbox may tilt as the mower follows ground contours. Change oil after the first 50 hours, then every 300-500 hours depending on operating severity. Clean the breather vent regularly — trailing mowers kick up more debris toward the gearbox than rear-mounted machines because the mower runs directly behind the tractor wheels.

When storing the mower for winter, run the PTO gearbox briefly to circulate warm oil through all bearing surfaces, then top up the oil level. This leaves a protective film on internal components that prevents corrosion during the idle months. Korea Ever-Power's technical team can advise on maintenance intervals specific to your operating conditions — contact us with your mower model and typical annual usage hours.

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