Hydraulic, Ground-Driven & Self-Propelled Hay Rakes: Full Comparison

Hay rakes are divided by drive mechanism into three primary categories: ground-driven (traction-powered by wheel-to-ground contact), PTO-driven (powered by the tractor’s power take-off shaft), and hydraulically actuated (using the tractor’s hydraulic system for wheel drive, angle adjustment, or fold). A fourth category — self-propelled rakes — exists at the high end of the commercial market as dedicated self-powered machines. Each drive system has different power requirements, maintenance characteristics, crop-quality outcomes, and capital cost profiles.

Choosing the wrong drive type for your application results in measurable performance loss. A PTO rotary rake running legume hay at full speed will produce 3–5x the leaf shatter of a ground-driven wheel rake at the same throughput. A ground-driven rake on a heavy, wet silage grass swath may stall or produce inconsistent windrow formation where a hydraulic rotary would process the material cleanly. The drive mechanism is not a secondary specification — it is the primary technical decision in hay rake selection.

This article compares all four drive types in detail: mechanism, power consumption, crop quality implications, tractor requirements, maintenance, and the specific operational conditions where each type delivers its best performance.

Ground-Driven Hay Rakes: Mechanism and Performance

Ground-driven rakes — the dominant type in commercial hay production globally — use traction between the wheel tines and the ground surface to drive wheel rotation. As the tractor moves forward, the angled wheels roll along the ground surface; friction between tine tips and the stubble/soil surface causes each wheel to rotate, sweeping material laterally into a windrow. No PTO connection, no hydraulic motor, and no external power source is required for the raking mechanism itself — only tractor forward motion.

The defining performance characteristic of ground-driven rakes is proportional tine speed. Because wheel rotation speed is determined by ground speed, the tines move faster when the tractor is travelling faster and slower when the tractor slows down. This is mechanically self-regulating: when the operator reduces speed in heavy, tangled material, the tines automatically become less aggressive. When speed increases in light material, the tines increase their sweep rate proportionally. There is no separate speed control, no RPM setting to optimise, and no risk of the mechanism continuing at full speed while the tractor slows for an obstacle or headland turn.

Tine tip speed at typical operating speeds (10 km/h) on a standard wheel rake is approximately 3–5 m/s, depending on wheel diameter and angle. This is below the threshold at which leaf shatter becomes a significant loss mechanism in dry legume crops — the critical advantage of ground-driven over rotary for high-value forage. Research data from USDA forage quality studies consistently shows leaf shatter rates of 4–9% for ground-driven wheel rakes versus 8–16% for PTO rotary rakes on dry alfalfa at comparable throughput.

The limitation of ground-driven rakes is their behaviour in heavy or wet material. Because wheel rotation depends on traction, a wheel that cannot develop sufficient ground friction — due to wet conditions, loose soil, or material piled too thickly in front of the wheel — can slip and stop rotating, causing material buildup and an uneven windrow. In silage grass at 60% DM moisture, a 6.0 m ground-driven rake may produce 10–15% lower windrow consistency than a PTO rotary at the same throughput, particularly in the first pass through a heavy swath. The 9LZ-6.0 finger wheel rake and the wider 9LZD-9.0 are both ground-driven and perform best in conditions where traction is adequate — dry to slightly damp crop on firm, dry soil.

Power consumption for tractor traction (not PTO) at 6.0 m width and 10 km/h on firm ground is approximately 8–12 kW (11–16 HP) — well within the capability of a 30 HP tractor. The machine draws no power from the PTO, no power from the hydraulic system (beyond the minimal demand for height adjustment), and imposes no parasitic load on the tractor’s drivetrain beyond the rolling resistance of the implement frame and transport wheels.

PTO-Driven Rotary Rakes: Mechanism and Performance

PTO-driven rotary rakes use the tractor’s power take-off shaft (540 RPM standard, 1000 RPM on some larger units) to power a gearbox that drives one or more rotor heads carrying spring tines. Tine tip speed on a standard single-rotor rake at 540 RPM PTO input is typically 8–12 m/s — significantly higher than ground-driven wheel rakes. This elevated tip speed gives rotary rakes their key advantage: the ability to handle heavy, wet, and tangled material that would slow or stall a ground-driven machine.

In silage grass production, PTO rotary rakes are the standard choice because silage is typically raked at higher moisture levels (40–65% DM) than dry hay, and the heavier, wetter swaths require the constant-speed, positive-drive tine action that a PTO mechanism provides. The tines sweep at the same speed regardless of ground speed — forward motion can slow for a headland turn or an obstacle while the rotor continues operating, preventing material buildup at the wheel periphery that would occur in a ground-driven machine slowing below its minimum traction threshold.

The trade-off is forage quality impact. At 10–12 m/s tine tip speed, leaf shatter in dry legume crops increases substantially. Alfalfa, clover, and similar high-leaf-fraction crops lose significantly more leaf protein and energy value through a rotary rake than through a ground-driven wheel rake in equivalent dry conditions. For silage operations where the crop is ensiled at high moisture and fermentation preserves quality, this is largely irrelevant. For premium dry hay destined for horse or dairy rations, it is a meaningful quality loss that directly affects sale price per tonne.

PTO requirement for small to mid-range rotary rakes is 540 RPM at 15–35 HP PTO. Larger twin-rotor units at 10–12 m working width require 60–90 HP at PTO, which limits tractor compatibility to mid-large commercial machines. The 9GL-2.5/2.9 mower-windrower operates at 540 RPM PTO across a 2.5–2.9 m cut width and is suited to tractors in the 35–75 HP range — a practical entry point for operations transitioning from ground-driven wheel rakes to PTO-driven equipment.

Hydraulic Hay Rakes: Where Hydraulics Add Function

Hydraulic actuation in hay rakes refers to multiple different systems, which are sometimes conflated under the single term “hydraulic rake.” It is important to distinguish between them because each adds a different function and different cost.

Hydraulic wheel angle adjustment: Allows the operator to change the rake’s windrow width from the tractor cab without stopping and manually adjusting wheel mounting brackets. This is useful for operations that frequently switch between baler types (round to square, or different pickup widths) or that rake different crops that optimally require different windrow widths. The hydraulic circuit demand is low — a single-acting remote with flow of 5–10 L/min at low pressure is adequate. The drive mechanism remains ground-driven; hydraulics only control wheel angle.

Hydraulic fold for transport: Wide rakes (9.0 m+) use hydraulic cylinders to fold the outer wheel sections inward for road transport, reducing transport width to under 3.0 m. This is a safety and compliance feature — driving a 9.0 m wide implement on a public road is illegal in most jurisdictions. The fold mechanism requires a double-acting hydraulic remote and approximately 15–25 L/min flow for smooth folding operation. Again, this is a structural function; the raking mechanism itself remains ground-driven.

Hydraulic wheel drive (fully hydraulic rake): A smaller category where hydraulic motors directly drive the rake wheels or rotor heads instead of ground traction or PTO shaft. Hydraulic wheel drive provides constant tine speed regardless of ground speed — similar to PTO drive in this respect — while allowing the operator to adjust tine speed independently of travel speed via hydraulic flow rate. The tractor must provide adequate hydraulic flow and pressure for continuous operation: typically 30–50 L/min at 180–210 bar for a full-width hydraulically driven rake. This is a high-end specification not standard on all tractors and adds significant system complexity and maintenance cost relative to both ground-driven and PTO alternatives.

For most commercial operations, “hydraulic hay rake” in practice means a ground-driven or PTO rotary rake with hydraulic fold and hydraulic wheel angle adjustment — not a hydraulically motor-driven machine. Fully hydraulic motor-driven rakes represent a small niche at the high end of the market and are not the standard when buyers ask about hydraulic rakes.

Hydraulic Feature	Function	Flow Required	Value Proposition
Height adjustment	Raise/lower wheel assembly	<5 L/min (intermittent)	Standard; available on all tractors with 1 remote
Wheel angle adjust	Change windrow width from cab	5–10 L/min (intermittent)	Useful if switching crops/balers frequently
Transport fold	Reduce width for road transport	15–25 L/min (intermittent)	Essential on 9.0 m+ rakes for road compliance
Hydraulic wheel drive	Motor-driven tines (independent of ground speed)	30–50 L/min (continuous)	High-end; high-capacity operations only

Self-Propelled Hay Rakes

Self-propelled rakes are standalone machines with their own engine, drivetrain, and operator cab. They are not a category most farms will purchase — the capital cost is substantial, and the machine does a single function (raking) that can be performed adequately by a tractor-mounted implement at a fraction of the cost. Self-propelled rakes are used primarily by large custom operators and farming enterprises processing thousands of hectares per season where the machine utilisation rate justifies the capital investment.

The operational advantage of a self-propelled rake is complete independence from tractor scheduling — the rake operates simultaneously with the tractor doing another task (mowing, baling), allowing a two-person operation to run mowing, raking, and baling concurrently with three machines and two operators. For custom operators charging per hectare and managing multiple client properties, self-propelled equipment allows maximum throughput during narrow weather windows. For single-farm operations under 1000 ha/year, the economics rarely support the investment.

Drive Type Comparison: Side-by-Side Summary

Criterion	Ground-Driven	PTO Rotary	Hydraulic Rotary	Self-Propelled
Leaf shatter risk	Low	Moderate–High	Moderate	Variable
Heavy/wet material handling	Moderate	High	High	Very High
Tractor HP required	Low (18–65 HP)	Moderate (35–90 HP)	Moderate–High	Self-powered
Maintenance complexity	Low	Moderate	High	Very High
Capital cost	Low–Medium	Medium	Medium–High	Very High
Best crop	Hay, legumes, straw	Silage, grass, heavy swaths	Silage, variable density	All crops, large scale
Minimum tractor size	18 HP (compact)	35 HP + PTO	55 HP + hydraulics	N/A

Operating Conditions That Determine Drive Type Selection

The decision between drive types is most reliably made by mapping your specific operating conditions against the performance profile of each type. The following scenarios represent the most common decision points in practice.

Scenario 1 — Dry hay operation, alfalfa or mixed legume/grass, moderate scale (50–200 ha/year): Ground-driven finger wheel rake is the correct choice. Low leaf shatter, no PTO required, compatible with 35–65 HP tractors, and lower capital and maintenance cost than PTO alternatives. Windrow quality is equal to or better than PTO rotary in dry conditions. The 9LZY-9.0 finger type hay rake at 9.0 m covers this volume range efficiently with 45–65 HP tractor compatibility.

Scenario 2 — Silage operation, grass dominant, wet conditions frequent: PTO rotary rake is the correct choice. Constant tine speed at full PTO RPM regardless of crop density ensures consistent windrow formation in heavy, wet material. Leaf shatter is irrelevant in silage production because fermentation in the clamp preserves protein and energy value independently of physical leaf attachment to stem.

Scenario 3 — Mixed operation, both silage and dry hay in the same season: A ground-driven 9.0 m wheel rake handles dry hay with lower leaf shatter. For silage raking, accept the slight compromise in windrow consistency of the ground-driven machine on wet material, or invest in a second PTO rotary implement dedicated to silage. Most operations in this situation use the wheel rake for both crops, accepting the 10–15% reduction in windrow consistency during silage runs rather than maintaining two machines.

Scenario 4 — Narrow weather windows, high throughput priority: Mower-rake combination eliminates one field operation entirely. The 9GL-5.0/5.6 mower-windrower cuts and windrrows in a single 5.0–5.6 m pass, saving one tractor pass over the entire field area per cut. This is the highest-throughput option for operations constrained by weather rather than by machine capacity.

Scenario 5 — Large-scale operation, 12.0 m working width requirement: The 9LH-12 horizontal hay rake at 12.0 m working width and 6–12 ha/h output serves operations with large open paddocks where the headland turn time is proportionally small. PTO and hydraulic fold capability are required; minimum tractor HP is 75+.

Maintenance Differences Between Drive Types

Ground-driven wheel rakes have the simplest maintenance profile of all rake types. The only moving parts subject to wear are the tines, tine hubs, and wheel bearings. There is no gearbox, no PTO shaft, no hydraulic motor, and no driveline to maintain. Seasonal maintenance is limited to tine inspection and replacement, bearing inspection and lubrication (or replacement on sealed-for-life units), and frame inspection for fatigue damage.

PTO-driven rotary rakes add a gearbox, PTO shaft with universal joints, and in twin-rotor units a distribution shaft and secondary gearboxes. Gearbox oil level must be checked and changed on the manufacturer’s specified interval — typically annually or every 200 operating hours. Universal joint wear is the most common failure mode on PTO rakes operated without adequate maintenance; a worn u-joint produces vibration that accelerates bearing wear throughout the driveline. PTO shaft protection (overrun clutch or shear bolt) must be functional — a PTO shaft that locks up on stone contact without a slip mechanism will damage the tractor PTO and potentially the gearbox.

Hydraulic systems add fluid condition, filter condition, hydraulic hose integrity, and cylinder seal condition to the maintenance checklist. Hydraulic oil in constant-duty systems (hydraulic wheel drive) must be changed on schedule; contaminated hydraulic oil destroys pump and motor components at high cost. Intermittent-use hydraulic systems (fold and angle adjust) are less demanding — check hose condition and cylinder rod seals annually and replace at first sign of fluid weeping.

Häufig gestellte Fragen

What is a hydraulic hay rake?

A hydraulic hay rake is most commonly a ground-driven or PTO rotary rake that uses hydraulic cylinders for transport fold, wheel angle adjustment, or implement height control — not a machine where hydraulics power the raking mechanism itself. Fully hydraulic motor-driven rakes are a specialist high-end category. When comparing rakes described as “hydraulic,” confirm specifically which functions are hydraulically actuated and whether the raking mechanism itself is ground-driven, PTO-driven, or hydraulic motor-driven.

Is a ground-driven hay rake better for hay quality than a PTO rake?

For dry hay, particularly legumes, yes. Ground-driven wheel rakes produce lower leaf shatter losses than PTO rotary rakes because tine speed scales with ground speed rather than operating at constant high RPM. For silage and heavy grass crops, PTO rakes provide better material handling and more consistent windrow formation in heavy or wet swaths.

Do I need a PTO to run a hay rake?

Only for PTO-driven models. Ground-driven finger wheel rakes require no PTO — they operate entirely from forward traction. This makes ground-driven rakes compatible with older tractors, compact tractors, and utility vehicles that have no live PTO. Confirm drive type on any rake you are evaluating — PTO is required for mower-rake combinations and rotary rakes, but not for standard finger wheel rakes.

What are the advantages of a self-propelled rake over a tractor-mounted one?

Operational independence — the rake works without tying up a tractor, allowing simultaneous mowing, raking, and baling with separate machines. This maximises throughput during narrow weather windows. The disadvantage is very high capital cost and dedicated maintenance for a single-function machine. Self-propelled rakes are economically justifiable only for large custom operators and enterprises processing 1000+ ha per season.

How much hydraulic flow does a hay rake need?

For height adjustment only: under 5 L/min, available from any tractor remote. For hydraulic fold on a 9.0 m+ rake: 15–25 L/min intermittent. For hydraulic wheel angle adjust: 5–10 L/min intermittent. For a full hydraulic motor-driven rake: 30–50 L/min continuous. Check your tractor’s hydraulic pump output and remote valve rating against these figures before specifying a hydraulic-fold or hydraulic-drive model.