Description
How the C3A Gearbox Works — Engineering Behind the Design
Power flows from the tractor’s PTO shaft at 540 r/min into the input connection — a 6-spline, 1-3/8 inch interface that matches standard UK agricultural tractors from 40 hp upward. Inside the cast iron housing, a set of precision-cut gears maintains the 1:1 ratio, preserving input torque while routing drive through 90 degrees to the mixer auger shaft — a 20-spline, 1-3/4 inch output optimised for high-torque mixing loads up to 92 kW. The sealed oil-bath lubrication system keeps all gear faces and bearing races bathed in SAE 90 gear oil throughout operation, preventing metal-to-metal contact even during extended multi-hour TMR (total mixed ration) batching sessions common on large-scale UK dairy units. The reinforced cast iron housing resists the constant vibration and shock loading inherent in mixing fibrous silage, whole-crop cereal, and chopped straw, without flexing or developing stress fractures over time. Machined input and output shaft bores maintain sub-0.05 mm alignment tolerances, so side-loading on bearings is minimised — a major factor in gearbox longevity. The entire assembly is a dimensional match to the original Comer C3A, meaning swap-out time on-farm is typically under two hours with standard hand tools.
Why UK Farm Engineers Specify This Gearbox
Direct-Fit Compatibility
Manufactured to Comer C3A dimensional drawings. Bolt pattern, shaft sizes, and housing footprint match exactly — no machining, no adapters, no delays.
92 kW / 540 rpm Rated
Handles the heaviest TMR loads — wet silage, wholecrop, mineral blocks — without heat stress or torque overload. Matches the power ceiling of most UK 100–130 hp tractor PTO outputs.
Sealed Lubrication System
Oil-bath design eliminates the daily greasing routine. First change at 50–70 hours, then every 500–700 hours — or annually. Perfectly suited to year-round UK livestock feeding schedules.
Cast Iron Durability
Heavy-wall cast iron housing resists cracking, vibration fatigue, and chemical attack from silage effluent — conditions that destroy lighter alloy alternatives within a single winter season.
Uniform Ration Quality
Consistent 1:1 power transfer keeps auger speed stable across the full mixing cycle — preventing ingredient stratification that results in variable dry matter intake between cows or batches.
Reduced Total Ownership Cost
Longer service intervals, fewer unplanned breakdowns, and a competitively priced unit compared to OEM replacements mean the total cost per year of operation is significantly lower.
Where This Gearbox Performs Across UK Agriculture
The horizontal feed mixer gearbox earns its place across the full spectrum of British livestock enterprises. On high-output dairy units in Cheshire or Devon, it sustains the continuous PTO demand of multiple TMR batches per day without temperature rise or power loss. Beef finishing units in the North of England rely on its torque capacity when processing dense, high-energy diets containing rolled barley, distillers’ grains, and baled straw. Sheep and goat operations on hill farms in Wales and Cumbria benefit from its efficiency at part-load — the gearbox transfers power cleanly even when the wagon is only partially filled. At equine livery yards, dietary precision matters for horse health and temperament; a gearbox that delivers consistent shaft speed ensures chaff, pellets, and supplements are integrated without dead zones in the mixing chamber. Poultry integrators running on-site feed preparation lines also find the 92 kW capacity sufficient for commercial-volume ingredient blending. In every scenario, the value is the same: dependable mechanical transmission that keeps the mixing system moving through the busy UK autumn and winter feeding period.
Customer Success — Real Farms, Real Results
Bradfield Dairy — North Yorkshire, UK
300-Cow Dairy Unit Cuts Gearbox Downtime by 70%
Bradfield Dairy had been replacing the gearbox on their Kuhn vertical-converted wagon every 18 months due to housing cracks from silage vibration. After switching to this horizontal feed mixer gearbox C3A replacement in autumn 2022, they completed two full winter feeding seasons — roughly 420 operating hours — without any mechanical intervention. Feed manager Rob Halley noted that ration consistency improved noticeably, with less variation in the cow diet leading to a 0.3 L/cow/day gain in average milk yield during housed periods. The sealed lubrication system was highlighted as a key factor: previously, staff had to manually grease the gearbox before each morning and afternoon feed, adding 20 minutes to daily labour.
“We’ve tried three different replacements over the years. This one is the first that’s genuinely matched the original Comer in terms of fit and durability. We won’t go back.” — Rob Halley, Feed Manager
“Ordered on a Tuesday, fitted by Thursday morning. Perfect match for our Trioliet wagon. The 1-3/4 inch output shaft slid straight in — not a millimetre of play. Excellent build quality for the price.”
“Our equine yard runs two feed mix cycles a day, 365 days a year. Previous gearboxes lasted maybe 14 months. This one is now into its second year with no sign of trouble. The oil-bath design is the difference.”
“I was sceptical about ordering a non-OEM part. The technical team emailed me a dimensional drawing before I placed the order, which confirmed the fit. Fitted in less than two hours. Running quietly — very happy.”
Custom Gearbox Engineering — Built Around Your Application
No two mixing wagon installations are identical. Our engineering team works directly with UK dealers, farm machinery workshops, and OEM mixer manufacturers to develop custom horizontal feed mixer gearbox configurations when the standard C3A specification does not fit. Variables we can adjust include shaft rotation direction, gear ratio (single-stage and multi-stage), input speed, output speed, input and output torque ratings, mounting face orientation, and housing dimensions. We also offer modified spline counts and shaft diameters for integration with non-standard PTO equipment or proprietary mixer auger drives. Prototyping, dimensional certification, and batch production are all handled in-house — no intermediary, no communication delays. UK customers working to a seasonal deadline (pre-winter housing, for example) can discuss priority lead times directly with our sales engineers. We also supply replacement gearboxes compatible with Bondioli & Pavesi, Brevini, Kuhn, Storti, Trioliet, Jaylor, and Schuler mixing wagons in service across England, Scotland, Wales, and Northern Ireland.
✓ Modified Shaft Configs
✓ OEM-Style Batch Supply
✓ Multi-Brand Replacement
✓ UK Technical Support
Internal Components & Construction Quality
Every horizontal feed mixer gearbox leaving the production line contains six interdependent subsystems, each selected and manufactured to the same performance brief. The cast iron housing provides the structural reference for all internal geometry — gear centre distances, bearing bore positions, and shaft exit angles are all held to tight machining tolerances from this single datum. Inside, the gear set is typically helical-cut for lower noise and more gradual load engagement compared to spur-tooth alternatives. High-load bearings are selected based on the specific radial and axial forces generated by the 92 kW input — undersized bearings are the most common cause of premature gearbox failure in this class of machine. Input and output shafts are made from alloy steel, induction-hardened at the spline roots to resist the fretting wear that develops when shaft-to-yoke fits loosen under vibration. Labyrinth seals and lip seals at both shaft exits prevent oil loss and block the ingress of silage dust and fine feed particles, which are abrasive enough to score bearing races within weeks if left uncontrolled. The complete assembly is pressure-tested before despatch.
Frequently Asked Questions
Ready to Order or Need a Custom Configuration?
Our UK-focused sales team responds quickly to enquiries for standard and custom horizontal feed mixer gearboxes. Whether you need one unit or a batch supply agreement, we can help.
agriculturalgearboxes.top — Horizontal Feed Mixer Gearbox specialists supplying UK agriculture | edit by gzl
