707-01-0J070 Komatsu WD600-3 Steering Cylinder Aftermarket Replacement

Product Overview

SEIGO’s aftermarket steering cylinder, part number 707-01-0J070, is a direct drop-in replacement for the Komatsu WD600-3 articulated wheel dozer — a roughly 43-tonne machine powered by the SAA6D170E-3 engine, used for heavy dozing, stockpile work and site preparation. Komatsu catalogues this part as Cylinder Assembly, Steering. The WD600-3 uses an articulated, full-hydraulic power steering system with two steering cylinders, each running a 140 mm bore and a 495 mm stroke.

On an articulated machine, the steering cylinders do the entire job of turning the machine — there is no steered axle. They extend and retract to pivot the front and rear frames about the centre hinge, working continuously every time the operator changes direction, under the full articulation load of a 43-tonne machine. This is a high-duty-cycle, high-side-load application: the cylinders see constant reversing loads, and the rod and gland take side loading as the frames articulate. Steering cylinder failure takes the machine out of service completely, because a wheel dozer cannot be steered with a failed steering cylinder.

The failure pattern is driven by that duty cycle: rod chrome wear and scoring from the constant reversing motion and site contamination, gland seal leakage, and bushing wear at the mounting eyes from the articulation load. SEIGO manufactures the 707-01-0J070 to address all three — a 42CrMo4 induction-hardened, hard-chrome-plated piston rod finished for wear and scoring resistance, an ST52 seamless honed steel barrel (cylinder tube 707-13-14610), heavy-duty mounting bushings (707-76-75030), and a genuine NOK (Japan) or Parker (USA) seal kit rated for the WD600-3 steering circuit at 210 kg/cm² (3,000 PSI).

Each cylinder weighs approximately 84 kg, is pressure tested at 1.5× rated working pressure before shipment from our Guangdong factory, and is backed by a 12-month or 2,000 operating-hour warranty. Because the WD600-3 uses two steering cylinders that share identical operating hours, we supply matched pairs on a single order. SEIGO also manufactures the WD600-3 lift cylinder (707-01-0J050) and tilt cylinders (707-01-0R050 / 707-01-0J060). Standard lead time is approximately 30 days ex-works, with expedited production available for machine downtime.

Product Specifications

* OEM part numbers, brand names and model designations are used for identification and cross-reference purposes only. SEIGO Machinery is an independent aftermarket manufacturer and is not affiliated with Komatsu Ltd.

Komatsu WD600-3 Cylinder Reference

The WD600-3 uses steering, lift and tilt cylinders. Part 707-01-0J070 is a steering cylinder. The main hydraulic cylinders are listed below.

Steering, lift and tilt cylinders are different parts and are not interchangeable. Confirm your machine serial number before ordering. SEIGO supplies all hydraulic cylinder positions for the WD600-3 — send us your serial number and the position you need.

Component Breakdown — WD600-3 Steering Cylinder

Komatsu catalogues the components of this steering cylinder assembly. SEIGO manufactures each of them and supplies them individually to hydraulic repair shops, as well as supplying the complete assembly.

Sub-component supply: for workshops rebuilding in-house, SEIGO supplies the rod, cylinder tube (707-13-14610), bushings (707-76-75030) and seal kit as individual items — typically 40–60% of the cost of a complete replacement cylinder. On steering cylinders, rod and bushing wear from articulation side load is the most common rebuild driver. Send us the component you need and your machine serial number for a quotation.

Why This Cylinder, Specifically

• Built for articulated steering duty. On a WD600-3 the steering cylinders turn the whole machine and take side load as the frames articulate. We finish the rod for wear and scoring resistance and fit articulation-rated eye bushings (707-76-75030), because rod scoring and bushing wear — not work-pressure blow-by — are what limit service life on this position.
• Manufactured to OEM dimensions. 140 mm bore, 495 mm stroke, built to the Komatsu steering cylinder specification so it reproduces the original steering geometry and articulation angle exactly — no change to turning radius or lock-to-lock.
• Replace steering cylinders as a pair. The WD600-3 uses two steering cylinders that share identical operating hours. If one is leaking or scored, the other is usually close behind. We supply matched pairs on a single order to keep steering balanced left and right.
• Real component breakdown. Komatsu publishes the cylinder tube (707-13-14610) and bushing (707-76-75030) as separate numbers, and we supply them individually. For a workshop rebuilding rather than replacing, that means rod-plus-seal-kit or a single bushing at a fraction of complete-cylinder cost.
• Whole machine from one source. We also make the WD600-3 lift cylinder (707-01-0J050) and tilt cylinders (707-01-0R050 / 707-01-0J060), so a fleet can source all hydraulic cylinders for the machine from one factory on one order.
• Full traceability and testing. ISO 9001:2015 manufacturing, 100% pressure tested at 1.5× rated working pressure, shipped in an ISPM-15 fumigated export crate with material certificate and test record.

FAQ

Q1: What are the bore and stroke of the WD600-3 steering cylinder?

A: The Komatsu WD600-3 steering cylinder (707-01-0J070) has a 140 mm bore and a 495 mm stroke, and operates at a system pressure of 210 kg/cm² (3,000 PSI). The machine uses two of them in its articulated, full-hydraulic power steering system. If you are cross-referencing an unmarked cylinder, measure the barrel and rod outside diameters and send us the pin-to-pin length to confirm the correct part.

Q2: How many steering cylinders does the WD600-3 have?

A: Two. The WD600-3 is an articulated wheel dozer with no steered axle — the two steering cylinders pivot the front and rear frames about the centre hinge to turn the machine. Because both cylinders share identical operating hours, we recommend replacing them as a pair, and we supply matched pairs on a single order.

Q3: Can I buy the cylinder tube, bushing or seal kit separately?

A: Yes. Komatsu publishes the cylinder tube as 707-13-14610 and the mounting bushing as 707-76-75030, and SEIGO manufactures both as individual items along with the rod and seal kit. For workshops rebuilding in-house, sub-component supply typically runs 40–60% of the cost of a complete replacement cylinder. On steering cylinders, rod and bushing wear from articulation side load is the most common single-item order. Send us the component and your machine serial number for a quotation.

Q4: What are the warning signs of a failing steering cylinder?

A: Watch for hydraulic oil weeping at the rod gland, slow or uneven steering response, the machine pulling to one side, play or knocking at the cylinder mounting eyes (bushing wear), and visible scoring on the exposed rod chrome. Because steering is safety-critical on an articulated machine, any of these should trigger inspection, and a failing cylinder should be addressed before it fails completely.

Q5: Do you supply the lift and tilt cylinders for the WD600-3 too?

A: Yes. SEIGO manufactures the WD600-3 lift cylinder (707-01-0J050) and tilt cylinders (707-01-0R050 / 707-01-0J060) as well as the steering cylinder. All hydraulic cylinders for the machine can be supplied from one factory on one order, with matching seal kits and sub-components. Send us your machine serial number and the positions you need.

Q6: What is the lead time and how does it ship?

A: Standard production lead time is approximately 30 days ex-works Guangdong, China, with expedited production available for machine downtime. Each cylinder ships in an ISPM-15 fumigated wooden export crate, FOB Shenzhen, CIF or DDP. At approximately 84 kg per cylinder, air freight is practical for urgent single-cylinder orders; sea freight is standard for planned replacements and matched pairs.

SEIGO Machinery is an independent aftermarket manufacturer. All OEM part numbers, brand names and machine model designations are used for identification and cross-reference purposes only. These aftermarket components are not manufactured by, endorsed by, or affiliated with Komatsu Ltd.