Zetor 25K

The Zetor 25K, an enduring symbol of agricultural heritage, embodies the essence of reliability and simplicity. With its iconic design and robust construction, this historic tractor remains a beloved choice for farmers and collectors alike. Renowned for its rugged performance and versatility, the Zetor 25K continues to command admiration for its timeless charm and enduring legacy in the annals of tractor history. Whether working the fields or showcased as a prized collectible, the Zetor 25K stands as a testament to the ingenuity and craftsmanship of its era, capturing the imagination of enthusiasts around the world.

TypeTwo-cylinder, vertical, four-cycle high-pressure Diesel
ValvesIn head, replaceable, wet cylinder liners
Bore4 1/5 in.
Stroke4 3/4 in.
Displacement1/4 gallon
Compression ratio18:1
Cylinder headWith precombustion chambers common for both cylinders
Fuel consumption7 ounces HP/hr
TypeWorm and worm gear
Reduction ratio1:17
Steering wheel diameter16 1/2 in.
AdditionalElectric horn button
Minimum turning radius21 ft. 3 3/4″
TypeDry, single-disc
Diameter11 in.
Pressure springs9
Speeds6 forward, 2 reverse
Speeds(miles per hour/hr)
First gear2.40
Second gear3.12
Third gear4.00
Fourth gear6.62
Fifth gear8.66
Sixth gear11.25
First reverse1.65
Second reverse4.25
Differential driving pinionMade of nickel chromium alloy steel
Bearings2 tapered roller bearings
Reduction ratio (pinion and differential crown wheel)4.7/1
Final reduction ratio (to rear wheel axles)48/1
TypeSteel casting, square section
FrontAutomotive with pneumatic tyres 6,50—16
RearDiscs with pneumatic tyres 9,00—36
Speed535 RPM at rated engine speed (1,600 RPM)
Spline shaft diameter1 3/8 in. (S. A. E. standard)
Diameter9 7/8 in.
Speed880 RPM at rated engine speed (1,600 RPM)
Belt speed3 ft. 9 3/5”/sec
Special orderBelt pulley shield available
InstrumentsOil pressure gauge, water temperature gauge (both with indirect light), headlights switch, glowing plug and starter switch, charging pilot lamp (ammeter substitution available on request)
Zetor 25K Overview

As a historical model in today’s context and a cherished piece among collectors, the Zetor 25K holds a special place in the annals of tractor history. Introduced during a period when agricultural mechanization was undergoing significant advancements, the Zetor 25K represented a pinnacle of tractor technology of its time, offering farmers a reliable and efficient solution for their farming needs.

From an overview perspective, the Zetor 25K exudes a timeless charm with its rugged yet elegant design, reflecting the craftsmanship and attention to detail characteristic of vintage tractors. Powered by a two-cylinder, vertical, four-cycle high-pressure Diesel engine, the Zetor 25K boasted formidable performance capabilities tailored to the agricultural demands of its era. With a displacement of 1/4 gallon and a compression ratio of 18:1, this engine delivered ample torque and power for a variety of farm tasks, from plowing fields to hauling loads.

The steering system of the Zetor 25K, featuring a worm and worm gear type mechanism with a reduction ratio of 1:17, epitomized simplicity and reliability, providing operators with precise control over the tractor’s movements. Paired with a minimum turning radius of 21 feet 3 3/4 inches, this steering setup facilitated maneuverability in tight spaces, ensuring efficient operation in the field.

The clutch system of the Zetor 25K, with its dry, single-disc configuration and nine pressure springs, exemplified durability and ease of use, allowing for smooth engagement and disengagement of power transmission during various agricultural tasks. Combined with a gearbox offering six forward and two reverse speeds, the Zetor 25K provided farmers with versatility and flexibility in adapting to different operating conditions, enhancing productivity on the farm.

The rear axle of the Zetor 25K, equipped with a differential driving pinion made of premium nickel chromium alloy steel and a reduction ratio of 4.7:1, symbolized robustness and reliability, ensuring optimal torque distribution to the rear wheel axles for enhanced traction and stability, even in challenging terrain.

Zetor 25K featured front automotive wheels with pneumatic tires and rear discs with pneumatic tires, offering a balanced combination of comfort and performance for agricultural operations. This tire configuration, along with the tractor’s sturdy construction, made the Zetor 25K a dependable workhorse on the farm, capable of withstanding the rigors of daily use.

As a historical model in today’s context, the Zetor 25K holds significant value among collectors and enthusiasts of vintage tractors. Its iconic design, coupled with its technological prowess for its time, makes it a sought-after piece for those passionate about preserving agricultural heritage. Whether showcased in collections or restored to its former glory for exhibition purposes, the Zetor 25K serves as a testament to the evolution of tractor technology and its enduring legacy in shaping modern agriculture.