Splined Yoke 04-With Ball Attachment

Splined Coupling Interface

The internal spline bore mates with the PTO output shaft on a tractor or prime mover. Standardised to 1 3/8-inch diameter in both 6-tooth (Z6) and 21-tooth (Z21) profiles, the spline distributes torque across multiple contact flanks simultaneously. This spread of load eliminates the concentrated stress points that would otherwise cause fretting wear and premature spline failure under cyclical loading — a common failure mode on older, plain-bore yoke designs that are still found on some legacy UK farm machinery.

Ball Detent Retention System

The ball attachment collar contains a hardened steel ball bearing seated in a radially drilled channel. When the yoke is pushed onto the PTO stub, the ball snaps into the corresponding annular groove machined into the stub shaft. This positive lock prevents axial disengagement under vibration, shock loading, or direction reversal — situations that cause plain collar designs to walk free. Disconnection requires deliberate manual retraction of the outer sleeve, a feature that meets the EN ISO 5674 safety requirements routinely specified by UK OEM procurement teams and farm equipment dealers.

Material & Surface Treatment

Each Splined Yoke 04 body is cold-forged from medium-carbon steel, then CNC-machined to final dimension. The spline teeth are induction-hardened to a surface hardness of 55–62 HRC while retaining a tough, ductile core — this combination resists both surface fatigue and brittle fracture under impact loads. External surfaces receive a zinc-phosphate pre-treatment followed by an electrophoretic paint coating, giving corrosion resistance suitable for the wet, muddy field conditions typical across the UK agricultural belt from Lancashire through to the Scottish Borders.

Multi-Series Compatibility

Dimensionally matched to Series 1 through 8 shaft assemblies, reducing the part numbers a workshop must hold in stock. A single procurement decision covers a wide spread of implements.

Rapid Field Swap

The ball detent engages and releases in under ten seconds without tools, cutting implement changeover time during busy harvest windows. Reduced downtime translates directly into more productive field hours per day.

Extended Service Intervals

Induction-hardened spline teeth combined with the phosphate-epoxy coating allow extended greasing intervals even in dusty cereal harvesting environments, reducing routine maintenance costs over a full season.

OEM-Grade Tolerances

CNC-machined to ISO 286 fit tolerances with spline accuracy to DIN 5480, making these components a direct drop-in for OEM supply programmes. UK machinery manufacturers and independent dealers can list this part with full confidence in dimensional repeatability across production batches.

UK & European Shipping

Stocked for rapid despatch to agricultural merchants, engineering wholesalers, and direct farm buyers across England, Wales, Scotland, and Northern Ireland, with full export documentation available for mainland European orders post-Brexit.

Arable & Mixed Farming

Rotary harrows, power harrows, seed drills, and fertiliser spreaders across the cereal belts of East Anglia, Lincolnshire, and the East Midlands.

Livestock & Grassland

Mowers, tedders, rakes, forage wagons, and slurry tanker pumps throughout the dairy counties of Cheshire, Somerset, and Devon.

Construction & Groundcare

Sweepers, augers, post-hole borers, and hydraulic power packs on compact tractors used by local authorities, groundskeepers, and civil engineering contractors.

Industrial Drive Systems

Stationary engine-driven pumps, generators, compressors, and processing machinery in food production, quarrying, and light manufacturing facilities throughout the UK.

Greenacre Field Services, a contract farming operation based near Fakenham in North Norfolk, runs a fleet of six tractors across approximately 4,200 hectares of arable ground. During the 2024 autumn drilling campaign, the team experienced repeated shaft disconnection on their primary power harrow — a failure traced to worn collar retention on the original equipment yoke. Unplanned downtime during a narrow weather window was costing them three to four hours per incident.

Their workshop manager sourced a set of Splined Yoke 04 with ball attachment units in the correct 4.0504D specification. Installation took under twenty minutes per shaft. Through the remainder of the drilling campaign — covering some 1,600 hectares — there was not a single unplanned disconnection. The positive ball-lock proved its value particularly in the heavy clay headlands where shock loading during tight turns had been the most common trigger for the previous failures.

“We have been buying these splined yokes for our power harrow rebuild programme for two seasons. The dimensional accuracy is genuinely impressive — they drop in without any fitting, and the ball detent has that satisfying positive click that tells you it is properly seated. We will not go back to the old open-collar type.”

“Our OEM supply agreement for compact tractor attachments required a yoke with EN ISO 5674 compliance. These parts arrived with full dimensional certification, passed our incoming inspection on the first batch, and the lead times from initial inquiry to delivery were well inside what our production schedule required. Good supplier to work with.”

“Running a groundcare contracting business in the South West means the kit takes a hammering on rough terrain. We switched our mower shafts over to these yokes two years ago and the ball attachment has not given us a single issue. The corrosion resistance is also noticeably better than what we were using before — important when the machines are out in all weathers.”

PTO Drive Shaft G Series

The G Series is the workhorse of the range — a general-purpose shaft assembly engineered for the broadest range of agricultural implements and tractor outputs up to mid-range horsepower. Suited to mixed farming operations across the UK.

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PTO Drive Shaft S Series

The S Series features an integrated safety guard and is designed specifically for applications where operator protection standards are paramount — including CE-marked machinery supplied to UK and European markets.

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PTO Drive Shaft L Series

The L Series is configured for extended-length applications where the distance between tractor output and implement input exceeds standard shaft coverage — used on trailed implements and wide-span machinery common in large-scale arable contracting.

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PTO Drive Shaft T Series

The T Series is the high-torque option in the catalogue, built for heavy implements such as stump grinders, rotary cutters, and industrial pumps where peak driveline loads regularly approach the shaft series limit.

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Our manufacturing facility operates a complete in-house production process covering cold forging, CNC turning and milling, induction hardening, spline broaching, and surface treatment — all under one roof. This vertical integration is what allows us to hold close tolerances across production batches and to respond quickly when a customer needs something outside the standard catalogue. For UK buyers, this matters most when you are specifying a replacement for a legacy machine that uses a non-standard bore diameter or a unique spline tooth count not covered by current catalogue dimensions.

Custom product development services include modified C-dimension assemblies for unusual implement geometries, alternative surface treatments for marine or chemical-splash environments, and bespoke packaging or part-marking for branded OEM supply chains. Minimum order quantities for custom runs are negotiable and we regularly support both small batch prototype programmes and high-volume annual supply agreements for UK and European equipment manufacturers. Our engineering team can review customer-supplied drawings or work from a sample part — whichever suits your procurement process.

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What is the difference between the Z6 and Z21 spline profiles on a splined yoke, and which one should I order for my tractor in the UK?

The Z6 profile (six-tooth, 1 3/8-inch diameter) is the older standard found on most tractors manufactured before the 1990s and on many smaller horsepower tractors still sold today, while the Z21 profile (twenty-one tooth, same outer diameter) is the finer spline introduced for higher-torque drives where the additional contact teeth distribute load more evenly. Check your tractor PTO shaft or the original implement shaft to count the teeth — a ten-second visual inspection is the most reliable method. Both profiles are available across all series in our catalogue, and we can supply matched pairs for shaft rebuilds.

How much does a Splined Yoke 04 with ball attachment cost, and where can I get a price or a bulk order quote for agricultural use in England?

Pricing depends on the series reference, spline profile, and order quantity — single-unit prices for replacement applications differ from the unit costs available on pallet or container quantities for OEM and wholesale buyers. The most direct route to an accurate price is to send your series number and quantity to [email protected] and we will respond with a formal quotation, usually within one business day. Volume pricing is available for orders of ten or more units of the same series reference.

Which series number should I choose when replacing a broken yoke on a Series 4 power harrow PTO shaft used on mixed arable farms across the UK Midlands?

For a Series 4 power harrow application, the 4.0504B (Z6 spline) or 4.0504D (Z21 spline) is the correct standard replacement. Measure the A, B, and C dimensions from the original yoke if possible and cross-reference against the specification table on this page to verify the match. If the original yoke has been discarded or is too damaged to measure, the implement serial number or manufacturer’s parts catalogue will carry the shaft series designation. When in doubt, send us the measurements and we will identify the correct part for you.

Do you supply Splined Yoke 04 components for OEM machinery manufacturers in the UK, and what is your typical lead time for a new supply agreement?

Yes, we actively supply UK and European OEM machinery manufacturers, both for serial production and for spare parts programmes. For standard catalogue items in volume, lead times after approval of a supply agreement are typically four to six weeks for initial shipment, with subsequent replenishment orders processed against agreed call-off schedules. For custom specifications — non-standard bore, modified length, or proprietary surface treatment — engineering review and tooling lead time should be discussed at the outset of the supply agreement discussion. Contact us at [email protected] to begin the conversation.

How do I safely disconnect a ball-attachment PTO yoke from the tractor stub shaft when swapping implements on a busy farm day?

Always disengage the tractor PTO and allow the shaft to come to a complete stop before attempting to disconnect. With the shaft stationary, grip the outer release sleeve of the ball collar and slide it rearward toward the implement — this retracts the ball bearing from its locking groove in the tractor stub shaft. While holding the sleeve retracted, pull the yoke axially off the stub. Never attempt to disconnect under load or while the shaft is rotating. If the sleeve feels stiff, a light application of general-purpose grease to the collar mechanism usually resolves the issue — a seized collar is most commonly caused by dried mud packing into the release channel.

Where in the UK can I find a reliable supplier of PTO drive shaft yoke components for agricultural and industrial machinery with fast delivery?

We supply directly to agricultural engineering workshops, farm machinery dealers, and end-user farms throughout England, Scotland, Wales, and Northern Ireland. Orders are processed and despatched from our distribution partner network with standard delivery timescales competitive for UK mainland destinations. Express delivery options are available for urgent harvest-season or emergency repair situations. To place an order or check stock availability for a specific series, email [email protected] with your required series reference and postcode for a delivery estimate.