707-01-16191 Komatsu WA900-3 Steering Cylinder (RH) Aftermarket Replacement

Product Overview

SEIGO’s aftermarket steering cylinder, part number 707-01-16191, is a direct drop-in replacement for the right-hand (RH) steering cylinder position on the Komatsu WA900-3 large wheel loader, serial numbers 10001 and up. Confirmed by ComponentsOnly and Komatsu’s own SIS parts catalogue as CYLINDER ASS’Y, STEERING, RH, this cylinder works in tandem with the left-hand counterpart 707-01-16181 to provide the full hydraulic steering force required to change the articulation angle of the WA900-3’s front and rear frames. The same cylinder assembly is also confirmed for use across the related Komatsu WA800, WA800L, WA900, WA900L, and WD900 platforms.

On the WA900-3 — a 107-tonne machine running full-hydraulic articulated steering with no mechanical backup — the steering cylinders are the only means by which the operator directs a vehicle carrying up to 13 cubic metres of blasted rock or ore at speed across a mining haul road or quarry floor. The WA900-3’s steering system is a high-flow, high-pressure full-hydraulic circuit operating through a dedicated steering pump, with the two steering cylinders acting directly on the articulation joint between front and rear frames. In a typical loading cycle — V-pattern truck loading, straight push at the pile, reversing and turning toward the truck — the steering cylinders complete dozens of full-lock-to-full-lock cycles per hour, each generating the full hydraulic steering force of a 107-tonne machine. The peak loads occur during tight turning at loaded dump position and during steering corrections on ramps and graded haul roads under full payload.

At 206 kg per cylinder — as documented in the Komatsu WA900-3 Service Manual (SEBM013514) weight table — the 707-01-16191 is a substantial high-pressure actuator. The most common failure modes are rod seal leakage from chrome scoring caused by road grit and dust contact at the wiper seal, internal bypass from piston seal wear under sustained full-lock steering loads, and rod chrome fatigue from repeated lateral bending at maximum articulation angle. Any steering cylinder failure on a 107-tonne loaded machine operating at mine-road speeds is a Category 1 safety event — this is not a component where deferred maintenance is acceptable.

SEIGO manufactures the 707-01-16191 with a 42CrMo4 induction-hardened, hard-chrome-plated piston rod to HRC 58–62, providing maximum surface resistance to scoring and chrome delamination in the exposed front-frame articulation zone. The cylinder barrel is ST52 seamless honed steel. A genuine NOK (Japan) or Parker (USA) seal kit is fitted throughout. Every unit is pressure-tested at 1.5× rated working pressure before shipment from our Guangdong, China factory, and is backed by a 12-month or 2,000 operating-hour warranty, whichever comes first. Standard lead time is 2–3 weeks, with a 5–7 day Rapid Production Track for mine-site and quarry emergency orders.

Technical Specifications Table

Machine Fitment & Serial Number Ranges

• Komatsu WA900-3 (S/N 10001-Up, produced 2007–2019) — fits 707-01-16191 RH; engine: SA12V140, 672 kW / 901 HP
• Komatsu WA900-1 (S/N 10001-Up) — fits 707-01-16191 RH; confirmed by HW Part Store seal kit coverage
• Komatsu WA900L — fits 707-01-16191 RH; confirmed by Komatsu SIS cross-reference
• Komatsu WA800 / WA800L — fits 707-01-16191 RH; confirmed by Komatsu SIS cross-reference
• Komatsu WD900 — fits 707-01-16191 RH; confirmed by Komatsu SIS cross-reference
• Komatsu WA900-3E0 / WA900-3LC (variant models) — confirm serial number with SEIGO engineering team before ordering

We recommend all customers provide their full machine serial number to SEIGO’s engineering team before ordering. As a safety-critical component, fitment confirmation is mandatory prior to order processing.

Key Features & Quality Points

• OEM-confirmed: CYLINDER ASS’Y, STEERING, RH for Komatsu WA900-3 — sourced from ComponentsOnly and Komatsu SIS parts catalogue
• Safety-critical component: manufactured to zero-tolerance OEM dimensional standards for a full hydraulic articulated steering system with no mechanical backup
• Covers WA900-1 and WA900-3 (SN 10001-Up) plus WA800, WA800L, WA900L, and WD900 under one part number
• OEM-documented cylinder weight 206 kg per Komatsu Service Manual SEBM013514 — matched in SEIGO’s manufactured assembly
• 42CrMo4 induction-hardened rod to HRC 58–62 — resists chrome scoring from road grit and dust at the articulation joint wiper seal zone
• ST52 seamless honed steel barrel for consistent bore geometry and long piston seal service life under full-lock steering loads
• NOK (Japan) / Parker (USA) premium seal kit — zero-leakage standard for safety-critical hydraulic steering circuit
• 100% pressure tested at 1.5× rated working pressure before shipment
• ISO 9001:2015 certified manufacturing process
• Drop-in fitment — no machine modification required
• 12-month / 2,000-hour warranty, whichever comes first
• Export-grade fumigated wooden crate packaging
• FOB Shenzhen / CIF / DDP shipping terms available

FAQ

Q1: Is SEIGO 707-01-16191 dimensionally identical to the Komatsu OEM part? A: Yes. Our 707-01-16191 is manufactured to match all OEM mounting dimensions, pin-eye bore diameters, rod diameter, stroke length, port locations, and thread specifications of the Komatsu original. It is a true drop-in replacement for the RH steering cylinder position on WA900-3 machines from serial number 10001 onward, requiring no modification to the machine.

Q2: What is the difference between 707-01-16191 and 707-01-16181? A: Parts 707-01-16191 and 707-01-16181 are the right-hand and left-hand steering cylinders respectively on the WA900-3. They are mirror-image assemblies acting on opposite sides of the articulation joint — one drives frame articulation to the right, the other to the left. Each machine requires one of each. The rod diameter, bore, and stroke are identical between the two; port orientation and pin-eye geometry differ to suit their respective mounting positions. SEIGO supplies both individually or as a matched LH/RH pair on a single purchase order.

Q3: Why is the WA900-3 steering cylinder classified as safety-critical? A: The WA900-3 uses a fully hydraulic articulated steering system — there is no mechanical steering backup. The two steering cylinders are the only means of directional control for a 107-tonne machine. A steering cylinder failure — through seal leakage, rod fracture, or internal bypass — removes directional control entirely. At mine-road or quarry operating speeds, this constitutes a Category 1 machine safety incident. Komatsu and most mine and quarry site maintenance standards therefore require periodic inspection of steering cylinder rod condition and seal integrity, and prompt replacement at the first sign of leakage or chrome wear.

Q4: What are the warning signs of a failing WA900-3 steering cylinder? A: Key indicators include: hydraulic oil leakage or weeping at the rod seal, most visible after a full shift as the rod cools; increased steering effort or slow steering response, particularly when making tight turns at the dump point or during V-pattern loading; steering drift requiring continuous correction to hold a straight line; play or knock at the articulation joint during directional changes; and visible chrome scoring or pitting on the rod surface during the pre-shift walk-around. Any of these symptoms must be reported to the maintenance supervisor immediately — on a machine of this class and weight, a steering incident is a serious site safety event.

Q5: Does 707-01-16191 also fit the WA800 and WD900? A: Yes. Komatsu’s own SIS parts catalogue confirms 707-01-16191 as the RH steering cylinder assembly across the WA800, WA800L, WA900, WA900L, and WD900 platforms in addition to the WA900-3. Please provide your full machine serial number and model to SEIGO’s engineering team when ordering for machines other than the WA900-3 to confirm the correct specification applies to your specific unit.

Q6: What is the lead time for 707-01-16191? A: Standard production lead time is 2–3 weeks ex-works Guangdong, China. For mine-site or quarry emergency orders — including steering system failures that have placed a machine out of service — our Rapid Production Track delivers in 5–7 working days subject to materials availability. International air freight to major hub airports adds approximately 3–5 days. Given the safety-critical nature of steering cylinders, we strongly recommend that mine and quarry operations maintain a minimum of one spare 707-01-16181/16191 pair in site stores for each active WA900-3 unit.

Q7: Should both steering cylinders be replaced at the same time? A: If one cylinder has failed, the opposite side must be closely inspected. Both cylinders operate under identical load and duty cycles — at similar operating hours, the second cylinder is typically at a comparable wear stage. Replacing both in a single planned maintenance window prevents a second steering failure shortly after return-to-service, and maintains balanced articulation forces across the frame joint. SEIGO supplies matched 707-01-16181 (LH) and 707-01-16191 (RH) pairs on a single purchase order at no additional lead time.

Q8: Do you supply to mine and quarry operations globally? A: Yes. We regularly supply WA900-class steering and hydraulic cylinders to operations across Australia (Pilbara iron ore, Bowen Basin coal, Kalgoorlie gold), Chile (Atacama copper and lithium), South Africa (Northern Cape iron ore, Bushveld platinum), Indonesia (Kalimantan coal, Papua nickel), Mongolia (via China rail/road), Canada, and West Africa. We support FOB Shenzhen, CIF, and DDP Incoterms.