Feed Mixer Series Planetary Gearbox
Compatible TMR Mixer Types:
Vertical Twin-Auger Mixer
Horizontal Mixer Wagon
Stationary TMR Mixer
Self-Propelled Mixer
Trailed Mixer Wagon
Truck-Mounted Mixer
Multi-Auger Paddle Mixer
Why Choose Our Feed Mixer Series Planetary Gearbox? — Feed mixing is among the most demanding gearbox applications in agriculture: daily continuous operation, high shock loads from bale processing, abrasive material contact, and alternating torque spikes from auger blockages. The Feed Mixer Series is engineered specifically for these conditions — with ductile iron housing, carburised alloy steel gears, integral oil passages eliminating external plumbing failure points, and PTO-direct input for 540 or 1000 RPM tractor drive. We supply 20+ sizes covering vertical single and twin-auger drives, horizontal auger and paddle mixer drives, and stationary electric motor-driven configurations. Direct replacement for Auburn Gear, Comer, Bondioli, Bonfiglioli, and other major OEM feed mixer gearbox brands. CE certified. In stock for same-week despatch on the most common models.
Feed Mixer Series Planetary Gearbox — Product Overview
The Feed Mixer Series Planetary Gearbox is the specialist member of our planetary gearbox family — engineered from the ground up for the unique demands of total mixed ration (TMR) feed mixer drives, rather than adapted from a general-purpose industrial gearbox. This distinction matters in feed mixing: a TMR mixer gearbox must survive daily continuous operation under the most demanding agricultural conditions — silage bale processing, whole-crop bale ingestion, repeated auger blockage and torque spike events, wet and abrasive material contact, and wide seasonal temperature variation — while maintaining the precise low output speed (typically 20–25 RPM) and high torque that uniform TMR mixing requires. General-purpose industrial gearboxes adapted to this application typically fail at the oil seals, the bevel input stage, or the output shaft bearings within the first two seasons; a purpose-built feed mixer gearbox engineered with these specific failure modes in mind delivers three to five times the service life.
The Feed Mixer Series covers both vertical auger drives — the most common configuration in trailed TMR mixers, where the gearbox mounts at the base of a vertical mixing auger and receives PTO power from above through a right-angle bevel input stage — and horizontal auger drives — used in horizontal paddle mixers, reel mixers, and truck-mounted TMR systems, where the gearbox mounts inline with the horizontal auger shaft. Both configurations use the same planetary reduction gear set family, sharing gears, bearings, and output shaft components across sizes — reducing spare parts complexity and improving parts availability for fleet operators running multiple mixer machines.
We supply 20+ standard sizes in the Feed Mixer Series, covering the full range of mixer capacities from small single-auger machines (4–8 m³) through to the largest twin-auger and multi-auger commercial dairy TMR systems (30+ m³). PTO input at 540 RPM or 1000 RPM is standard for trailed machines; hydraulic orbit motor input and electric motor input (IEC flange) are available for stationary and self-propelled configurations. All models carry CE certification and are supplied with a complete quality documentation package including factory acceptance test report.
What Makes a Feed Mixer Gearbox Different
Feed mixer planetary gearboxes are designed to a different specification from general-purpose industrial planetary gearboxes in the same torque class. Understanding these differences explains why purpose-built feed mixer gearboxes outperform general-purpose alternatives in this application:
When a vertical auger encounters a large silage bale or a partially-frozen forage block, the auger stalls momentarily and then breaks through — generating a torque spike that can reach 3–5× the nominal rated torque in milliseconds. Feed mixer gearbox gear sets are designed and heat-treated to absorb these impact loads without tooth fracture, using higher-specification alloy steels and deeper case hardening depths than equivalent industrial gearboxes.
External oil lines and hoses on adapted industrial gearboxes are the most common failure point in feed mixer applications — they are exposed to impact from mixer material, to frost cracking in winter, and to vibration-induced fatigue cracking from daily tractor PTO operation. The Feed Mixer Series housing is machined with integral oil passages and channels, eliminating all external plumbing. This single design feature eliminates the most common cause of oil loss and gearbox seizure in the field.
The output shaft of a vertical feed mixer gearbox must simultaneously carry the full radial load of the auger weight and material load, the torsional load of the mixing torque, and the bending moment of off-centre load application — while rotating at 20–25 RPM for up to 4–6 hours per day throughout a 10–20-year machine life. The Feed Mixer Series uses a one-piece forged alloy steel output shaft — not a fabricated assembly — to eliminate the fretting corrosion and fatigue failure points that develop at fabricated joint interfaces under these combined loads.
The Feed Mixer Series is designed for direct PTO input — the gearbox input flange matches the standard 6-spline (540 RPM) or 21-spline (1000 RPM) PTO shaft profile as the primary input, not as an adaptor added to a motor-input gearbox. PTO input speed must not exceed 540 RPM to achieve the target output speed of 20–25 RPM across the standard gear ratio range. This direct PTO compatibility ensures the gearbox centreline is correctly positioned relative to the mixer frame without requiring additional adaptor structure.
Feed mixer gearboxes operate in environments where direct material impact on the gearbox housing is routine — forage bales, stone contamination in silage, and auger-ejected material can all strike the gearbox housing during normal operation. Ductile iron (GGG-50) housing provides the impact and notch resistance needed to withstand these field conditions without cracking — grey cast iron alternatives commonly used in budget gearboxes fracture under these impact conditions.
All Feed Mixer Series models are compatible with standard shear bolt overload protection on the PTO input — shear bolts sized to protect the gearbox are specified in the installation documentation. Cam-type torque-limiting clutch input shafts are also available as a factory option for operators who prefer automatic reset overload protection. The shear bolt interface dimensions match standard PTO shaft shear bolt patterns used by Weasler, Walterscheid, and other PTO shaft manufacturers.
Feed Mixer Gearbox — OEM Brand Replacement Coverage
Our Feed Mixer Series gearboxes are engineered as direct dimensional and performance replacements for the following OEM feed mixer gearbox brands. Submit the existing gearbox brand and model number from the nameplate and we confirm the correct Feed Mixer Series replacement with dimensional drawing within 48 hours.
① Auburn Gear — VM / HM Series Feed Mixer Drives
Auburn Gear (USA) VM and HM Series feed mixer drives are the most widely specified North American OEM feed mixer gearbox — used as original equipment on Jaylor, Supreme, Kuhn Knight, Patz, Roto Mix, and numerous other North American TMR mixer brands. Our Feed Mixer Series replicates all critical dimensions — housing bolt pattern, output shaft interface, PTO input flange, and SAE A/C/D hydraulic motor mounting face — for confirmed direct replacement. Key models covered: VM10, VM20, VM30 (vertical) and HM10, HM20, HM30 (horizontal). Both planetary gear set and right-angle bevel input assembly are available as complete units or as separate replacement sub-assemblies.
② Comer Industries — PG / PGA / PGR Series
Comer Industries (Italy) PG, PGA, and PGR series planetary gearboxes are the most widely used European OEM feed mixer drives — original equipment on Penta, BvL, Faresin, Seko, Marmix, and other European and South American TMR mixer brands. Our Feed Mixer Series covers the full Comer PG/PGA agricultural series with confirmed dimensional replacement, including the planetary gear set, bevel input stage, output shaft, and housing bolt pattern. The Comer PGA1602 is among the most frequently ordered replacement models in the Feed Mixer Series range.
③ Bondioli & Pavesi — Feed Mixer Gearbox Series
Bondioli & Pavesi (Italy) feed mixer planetary gearboxes are widely used as original equipment and service replacement parts across European and Australian TMR mixer markets. Our Feed Mixer Series covers the corresponding Bondioli models with matched planetary gear set dimensions, output shaft geometry, and PTO input flange standards.
④ Bonfiglioli — 300 Series Auger & Cutter Drives
Bonfiglioli (Italy) 300 Series inline and right-angle planetary gearboxes in the 1,000–18,000 N·m torque class are specified as auger and cutter drives on a range of European self-propelled and stationary TMR mixers. Our Feed Mixer Series covers the relevant Bonfiglioli 300 Series configurations with confirmed dimensional replacement — particularly the 301R, 303R, and 306R right-angle configurations most commonly used in feed mixer auger drives.
⑤ Additional OEM Brand Coverage
Beyond the four primary OEM brands above, our Feed Mixer Series cross-reference database covers replacement gearboxes for the following TMR mixer brands where the OEM gearbox brand is one of those listed above:
Jaylor · Supreme Industries · Kuhn Knight · Patz Corporation · Roto Mix · NDE (New Direction Equipment) · Oswalt · Schuler · Gehl · Henke · Harsh International · Farmaid · Kirby · Lucknow
Penta · BvL (van Lengerich) · Faresin · Seko · Marmix · Euromix · Kuhn · Keenan · Strautmann · Siloking · Teagle · Buschhoff · Tatoma · Sgariboldi
Cattlelac · Monomixer · Turbo Max · Digi-Star (drive components) · Weasler (driveline) · Walterscheid (driveline) · Schwartz · Val Metal · Multiple OEM brands on request
Free OEM Replacement Cross-Reference: Send us the brand name and model number from the gearbox nameplate, the mixer machine brand and model, and — if available — the output torque or mixer capacity. We confirm the Feed Mixer Series replacement model, part number, and price within 48 hours. For urgent breakdown situations, contact us directly for expedited same-week despatch on stocked models. Submit your cross-reference request →
How the Feed Mixer Planetary Gearbox Works
The Feed Mixer Series gearbox achieves the high output torque and low output speed required for TMR auger mixing through a multi-stage planetary reduction system — either with or without a right-angle bevel input stage, depending on the mixer configuration:
PTO Input — 540 or 1000 RPM
The tractor PTO shaft drives the gearbox input at 540 RPM (6-spline) or 1000 RPM (21-spline). For vertical auger mixers, a spiral bevel gear first stage redirects the horizontal PTO input to the vertical output centreline. For horizontal auger mixers, the PTO input is coaxial with the output and the bevel stage is omitted. Input speed must not exceed 540 RPM to achieve the target output speed of 20–25 RPM.
Bevel Stage (Vertical Only)
A spiral bevel gear pair redirects the tractor PTO power from horizontal (longitudinal) to vertical. This 90° turn is essential for vertical auger mixers — the PTO shaft enters horizontally at the rear of the mixer, and the auger must rotate on a vertical axis. The bevel stage also provides a first stage of speed reduction before the planetary stages.
Multi-Stage Planetary Reduction
One to three planetary gear stages multiply torque while reducing speed to the target output range of 20–25 RPM. Each stage uses multiple planet gears sharing load — providing the torque density needed to mix silage, whole bales, and concentrated supplements simultaneously. The planetary arrangement is far more compact than an equivalent spur gear or worm gear reduction in the same torque class.
High-Torque Low-Speed Output
The final planetary carrier drives the one-piece forged alloy steel output shaft at 20–25 RPM with the full rated output torque applied continuously across the auger mixing cycle. The output shaft interface matches the auger shaft coupling standard of the original OEM mixer machine — confirming that no modification to the auger shaft coupling or mixer frame is required for a bolt-on replacement.
Overload Protection — Shear Bolt
The PTO input shaft includes a shear bolt protection system — shear bolts sized to fail before the peak torque exceeds the gearbox's structural limit protect both the gearbox and the tractor PTO from blockage damage. Cam-type torque-limiting clutch input is available as a factory option. The shear bolt rating is specified in the installation documentation for each Feed Mixer Series model.
Core Advantages
Eight reasons livestock farm managers and mixer machine dealers specify our Feed Mixer Series as their first-choice OEM replacement:
Every design decision — gear material, case hardening depth, housing casting method, output shaft manufacturing process, and oil passage routing — is made with the specific failure modes of feed mixer gearboxes in mind. This is not a general-purpose gearbox adapted to feed mixing; it is a feed mixer gearbox that happens to share planetary technology with our industrial range.
We supply 20+ standard Feed Mixer Series sizes covering mixer capacities from 4 m³ to 30+ m³, single and twin auger drives, horizontal and vertical configurations, and PTO, hydraulic motor, and electric motor inputs. This is the broadest single-source feed mixer gearbox range available from a Chinese manufacturer, eliminating the need to source different gearbox brands for different mixer machines in the same fleet.
The most common Feed Mixer Series models — covering the Auburn Gear VM10/VM20, Comer PGA1602, and equivalent sizes — are held in finished-goods stock for same-week despatch. Feed mixer gearbox failures are typically breakdown events that stop daily feeding operations; a stocked replacement available within 5 working days is the defining purchasing criterion for most farm managers and dealers.
Ductile iron housing resists impact from feed material without cracking. Integral machined oil passages in the housing eliminate the external hoses and fittings that are the primary source of oil leaks and gearbox seizure in field conditions — replicating the Auburn Gear integral oil passage design that defines the North American feed mixer gearbox standard.
The one-piece forged alloy steel output shaft eliminates the fretting corrosion and fatigue failure risk of fabricated shaft assemblies at the combined radial, torsional, and bending loads of vertical auger drive service. This is the same construction standard as Auburn Gear OEM specification and provides the service life needed for a 10–15-year mixer machine working life.
Our cross-reference database covers Auburn Gear, Comer, Bondioli, Bonfiglioli, and the full range of North American and European mixer machine brands that use these gearboxes as original equipment. A dealer or farm manager can order a single Feed Mixer Series part number for replacement across their entire mixed-brand mixer fleet.
Where only the planetary gear set (planet gears, planet carrier, sun gear, and ring gear) has failed — and the bevel input stage and housing are still serviceable — we supply the planetary sub-assembly as a separate replacement kit. This significantly reduces the cost of field repair versus full gearbox replacement, and aligns with the Auburn Gear and Comer aftermarket service model.
Every Feed Mixer Series unit carries CE certification and is supplied with a factory acceptance test report, material certificates, gear tooth inspection records, and an installation/maintenance manual in English. This documentation package satisfies the requirements of European machinery directive compliance for mixer machine service replacements.
Feed Mixer Gearbox Application Scenarios
The Feed Mixer Series covers the full range of TMR feed mixer configurations used in modern livestock production worldwide:
Vertical Single-Auger Trailed Mixer
The most common TMR mixer configuration in North American and European dairy farming — a trailed wagon with one or two vertical augers driven by tractor PTO. The gearbox mounts at the base of the auger on a vertical centreline and receives PTO power through a right-angle bevel input. Capacity range typically 8–30 m³. Brands: Jaylor, Supreme, Kuhn Knight, Patz, Penta, BvL, and many others.
Vertical Twin-Auger Mixer
Large-capacity vertical mixers with twin counter-rotating augers — each auger requires its own independent gearbox drive, with the two gearboxes typically mirror-imaged to drive the counter-rotation direction. Used on large commercial dairy operations with 500+ head. Requires matched pairs of Feed Mixer Series gearboxes with opposite output rotation direction specifications.
Horizontal Reel & Paddle Mixer
Horizontal reel mixers and horizontal paddle mixers use a coaxial (inline) gearbox configuration — the PTO input shaft and the horizontal auger output shaft are on the same centreline. This configuration omits the bevel input stage and uses only the planetary reduction stages, providing a simpler and more compact gearbox than the vertical configuration. Common on Roto Mix, NDE, and certain Kuhn models.
Stationary Electric Motor-Driven Mixer
Stationary TMR mixers in large-scale commercial dairy and feedlot operations are typically driven by electric motors rather than tractor PTO — enabling continuous or scheduled automated feeding without a tractor. The Feed Mixer Series with IEC B5 electric motor input flange or variable frequency drive motor connection replaces the original gearbox in these fixed installations with the same output shaft interface and torque rating.
Self-Propelled & Truck-Mounted Mixer
Self-propelled TMR mixers and truck-mounted mixer bodies use hydraulic motor-driven gearboxes rather than PTO — the vehicle or truck engine powers a hydraulic pump which drives the mixer auger through a hydraulic orbit motor mounted on the Feed Mixer Series gearbox. SAE A, B, C, and D hydraulic motor flange options are available in the Feed Mixer Series for these applications, replacing Siloking, Faresin, and other self-propelled mixer OEM gearboxes.
Multi-Auger Feed Processing Systems
Large-scale automated feeding systems with multiple simultaneous auger drives — including feed distribution systems in covered yards and housed beef operations — require multiple gearbox units per installation. The Feed Mixer Series' 20+ size range, consistent mounting interface, and shared spare parts across sizes make it the practical choice for multi-machine fleet procurement by integrators and large-scale livestock operators.
Feed Mixer Gearbox — Frequently Asked Questions
Common questions from farm managers, machinery dealers, and service technicians sourcing TMR feed mixer gearbox replacements:
The Auburn Gear VM20 is covered by a confirmed Feed Mixer Series equivalent in our cross-reference database. To confirm the correct part number, provide the Auburn Gear VM20 part number from the gearbox nameplate — Auburn Gear uses a specific suffix code that identifies the planetary gear ratio and output shaft configuration. If the nameplate is unreadable, provide the Supreme mixer model number and mixer capacity (m³ or cubic feet) and we identify the correct gearbox specification from our Supreme mixer compatibility database. We aim to confirm the part number and deliver within 5 working days on stocked models.
Yes. Where the bevel input stage and housing are still serviceable and only the planetary gear set has failed, we supply the planetary sub-assembly as a separate replacement kit — including planet gears, planet carrier, sun gear, ring gear, and all bearings. This approach is more cost-effective than full gearbox replacement and is the preferred method for Auburn Gear and Comer gearbox service. Provide the complete gearbox model number and we confirm the correct planetary kit part number and ratio for your specific unit.
For tractor PTO-driven feed mixer gearboxes, the input speed must not exceed 540 RPM to achieve the standard output speed of 20–25 RPM. Running a 540 RPM PTO-standard gearbox from a 1000 RPM PTO without the correct ratio gearbox will result in output speeds of 35–45 RPM — too fast for effective TMR mixing and damaging to the gearbox in high-torque mixing conditions. Always verify that the tractor PTO speed matches the gearbox input rating. If your tractor operates at 1000 RPM PTO only, specify a Feed Mixer Series model with a 1000 RPM input rating when ordering.
Shear bolts are the simplest and least expensive overload protection — they fail at a defined torque, require the machine to be stopped for replacement, and provide very direct protection for the gearbox. They are the standard specification for the majority of feed mixer gearboxes and are the correct choice for most farm operations. Torque-limiting (cam-type) clutches automatically reset after an overload without stopping the machine — they are preferred on large commercial operations where stopping the mixer to replace a shear bolt represents significant operational disruption, or where the risk of operator injury from repeated shear bolt replacement is a concern. We supply both options; specify your preference when ordering.
The three most common causes of feed mixer gearbox failure in order of frequency are: (1) oil loss through seal or external plumbing failure — leading to gear and bearing wear and eventual seizure; (2) planetary gear tooth fracture from overload shock — typically caused by auger blockage without shear bolt protection in place, or by operating at incorrect PTO speed; (3) output shaft bearing failure from overloading — typically from operating the mixer beyond its rated capacity or from failure to replace worn bearing seals. The Feed Mixer Series addresses all three failure modes with integral oil passages, high-specification gear materials, and heavy-duty output shaft bearings rated for the combined radial, torsional, and bending loads of vertical auger drive service.
Yes. The Comer PGA1602 and PGA2002 are among the most frequently ordered Feed Mixer Series replacement models in our range — used as original equipment on Penta, BvL, and numerous European and South American mixer brands. We maintain finished-goods stock of the Feed Mixer Series equivalents for same-week dispatch. Provide the Comer PGA part number from the gearbox nameplate and we confirm the exact replacement model, including the planetary gear ratio and output shaft configuration.
Quality Assurance
- ✓ ISO 9001:2015 Certified Production — all manufacturing processes from raw material incoming inspection to final assembly and test are controlled under our certified QMS.
- ✓ CE Declaration of Conformity — all Feed Mixer Series units carry CE certification, satisfying EU Machinery Directive requirements for mixer machine service replacements in the European market.
- ✓ 100% Loaded Factory Acceptance Test — every unit run at rated torque and input speed; oil temperature, vibration, noise, and seal integrity recorded; full test report supplied with every unit.
- ✓ High-Specification Alloy Steel Gears — planetary and bevel gears manufactured from 20CrMnTi / 18CrNiMo7-6 alloy steel; carburised and hardened to 58–62 HRC with greater case depth than standard industrial gearboxes to absorb the impact loads of bale processing.
- ✓ One-Piece Forged Output Shaft — one-piece alloy steel forged output drive shaft on all Feed Mixer Series models; no welded or multi-piece shaft assemblies.
- ✓ OEM Cross-Reference Verified — every Auburn Gear, Comer, Bondioli, and Bonfiglioli cross-reference in our database is confirmed against OEM installation drawings before being confirmed to a customer.
How to Order a Feed Mixer Series Replacement
Read the Nameplate
Record the gearbox brand (e.g., Auburn Gear, Comer) and full model/part number from the nameplate. Also, note the mixer machine brand and model if available.
Submit Cross-Reference
Send nameplate data to our team. We confirm the Feed Mixer Series equivalent part number and delivery time within 48 hours — often same-day for stocked models.
Confirm Options
Confirm whether a complete gearbox or planetary sub-assembly only is required, shear bolt or torque-limiting clutch preference, and PTO input speed (540 or 1000 RPM).
Receive Quotation
Price, lead time, and installation drawing supplied. For stocked models, invoice and despatch notification is typically the same day as order confirmation.
Tested & Shipped
Every unit FAT-tested at rated load before shipment. Test report, material certificates, and CE documentation included. Packaging designed to withstand agricultural supply chain handling.
Related Products — Feed Mixer Driveline
PTO Shafts & Driveline Components for Feed Mixers
A feed mixer replacement gearbox is only as reliable as the PTO shaft and driveline components connecting it to the tractor. Our partner site supplies a comprehensive range of CE-rated PTO shafts, overrunning clutches, shear bolt assemblies, and torque limiter shafts — purpose-spec'd for feed mixer duty with the correct torque rating, shaft profile, and guard specification for vertical auger mixer applications. One-stop supply of both the gearbox and the complete replacement driveline reduces the time the mixer is out of service.
Profile 6 and Profile 8 telescopic shafts for 540 and 1000 RPM PTO — rated to the torque class of the Feed Mixer Series gearbox and supplied with CE-compliant guard assemblies for agricultural PTO safety regulation compliance.
Freewheel clutches prevent inertia back-torque from the high-momentum vertical auger reaching the tractor PTO when the tractor decelerates — a common cause of PTO shaft and gearbox input shaft fracture on vertical mixer drives.
Cam-type torque-limiting clutches — preset to the Feed Mixer Series gearbox protection rating — automatically reset after overload without stopping the machine. Replaces shear bolt protection on high-throughput commercial operations.
Ready to Replace Your Feed Mixer Gearbox?
Whether you need a complete replacement gearbox for an Auburn Gear VM/HM Series, Comer PGA/PGR, Bondioli, or Bonfiglioli feed mixer drive — or just the planetary sub-assembly for a gearbox whose housing is still serviceable — send us the gearbox brand and part number from the nameplate and we confirm the Feed Mixer Series replacement within 48 hours. For urgent breakdowns, contact us directly for same-week despatch on stocked models. Contact our team now →
