Request Pricing \u2014 QJ904 Heavy-Duty Series<\/a><\/p>\n63 mm bore \u00b7 250 mm stroke \u00b7 639 mm C-C \u00b7 FOB Ningbo<\/p>\n<\/div>\n<\/div>\n<\/div>\n
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Engineering Overview: QJ904.31.019 Large-Bore 63 mm Hydraulic Steering Cylinder for Heavy-Duty QJ904 Platform Tractors with High Front Axle Load<\/h2>\n
The QJ904.31.019 Hydraulic Steering Cylinder for Tractor<\/strong> represents a significant step up in both bore and force output within the QJ-series range. The QJ904 platform designates a larger tractor family\u2014typically 75\u2013100 hp machines\u2014where the front axle carries substantially higher static and dynamic loads than the QJ554-class machines covered in Products 8 and 9. The 63 mm bore is the standard steering cylinder size for this class, producing 37.4 kN extension force at 12 MPa operating pressure\u201431% higher than the 55 mm bore QJ554-1 cylinder and 137% higher than the compact QJ554.31.020-1. This force margin is necessary for confident steering in loaded four-wheel-drive configurations with front ballast, front loader attachments, or wide dual-tyre front axle setups common in primary tillage applications across Australia, Canada, and Brazil.<\/p>\nThe 35 mm rod at 250 mm stroke yields an Euler buckling load of approximately 146 kN under fixed-pinned end conditions\u2014a 3.9\u00d7 safety factor over the rated extension force. This is a tighter margin than the QJ554-1’s 4.2\u00d7 factor, reflecting the proportionally larger bore and higher force that the QJ904 cylinder must sustain. The 639 mm C-C is consistent with the wide front axle beam of the QJ904 platform. The stroke-to-C-C ratio of 0.39 is the second-lowest in this series, confirming that as the QJ-platform machines grow larger, the bracket span grows faster than the steering travel requirement\u2014a geometry driven by the physical width of the front beam section rather than the steering arm kinematics.<\/p>\n
The “019” drawing number in QJ904.31.019 distinguishes this from other QJ904 steering subassembly components sharing the “31” (front axle steering) group prefix. Procurement engineers should cross-check the full part number\u2014not just the QJ904 prefix\u2014to avoid ordering an adjacent component in the same group, such as a drag link end or steering valve fitting that shares the QJ904.31.xxx designation pattern.<\/p>\n
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Hydraulic Performance: 63 mm Bore Force Calculation, High-Volume Stroke Fluid Demand, and Seal Specification for the QJ904 Heavy-Duty Tractor Steering Cylinder<\/h2>\n
Bore area is 3,117 mm\u00b2; rod area is 962 mm\u00b2 (35 mm rod). At 12 MPa, extension force is 37.4 kN and retract force is 25.9 kN\u2014a retract-to-extend ratio of 69%, the highest in this series. The high retract ratio is a direct result of the relatively compact 35 mm rod in the larger 63 mm bore, leaving a wide annular rod-side area (2,155 mm\u00b2) that generates meaningful retract force. Full extension displaces 779 cm\u00b3\u2014the second-largest volume in this series after Product 12. At a 2.0-second lock time, the required pump flow is approximately 23.4 L\/min, which falls within the operating range of mid-size tractor hydraulic systems in the QJ904 hp class but must be verified against the installed pump’s rated flow at the tractor’s normal operating RPM. QJ904 platform tractors typically run hydraulic systems designed around 20\u201330 L\/min pump outputs, so this cylinder’s demand is matched to the system architecture.<\/p>\n
Barrel tube is 20# seamless precision steel, honed to Ra \u2264 0.4 \u00b5m across the full 250 mm stroke. The 63 mm bore diameter is well within the standard honing range for agricultural cylinder production, allowing consistent bore geometry without the non-standard tooling concerns that apply to the 41 mm bore of Product 8. Rod is 40Cr alloy steel (AISI 5140), heat-treated to 28\u201332 HRC, hard chrome plated to 25\u201330 \u00b5m, and ground to h6 tolerance. The 35 mm chrome rod surface at full extension\u2014250 mm of exposed rod length\u2014represents the largest corrosion-risk zone among the single-rod cylinders in this range. The 25\u201330 \u00b5m chrome thickness specification is the minimum required to provide reliable protection over this exposed length in outdoor storage and field operation conditions. Seal kit: PU piston U-ring (primary), NBR O-ring (secondary), PU rod U-seal, and reinforced-fabric PU wiper seal rated for the 35 mm rod OD.<\/p>\n
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OEM Fitment Verification: 639 mm C-C, 35 mm Rod Clevis Pin, and Part Number Disambiguation for the QJ904.31.019 Large-Bore Hydraulic Steering Cylinder Replacement<\/h2>\n
Clevis pin bore diameter is 32 mm H7 at both ends on the QJ904.31.019\u2014the largest clevis pin in this twelve-product series, reflecting the heavier lateral load capacity required at the mounting interfaces of a 63 mm bore, 37.4 kN steering cylinder assembly. Confirm the axle bracket pin bores are 32 mm (not 30 mm, which is used on the QJ554-1 variant) before ordering. A 2 mm diameter mismatch between the clevis pin and bore produces either an interference condition that prevents assembly or a 1 mm radial clearance that allows destructive impact loading on the clevis. Five-parameter verification: 63 mm bore, 35 mm rod, 250 mm stroke, 639 mm C-C, 32 mm clevis pin. Any supplier that cannot confirm all five parameters from a dimensional certification document should be considered unverified for this application.<\/p>\n
For international distributors stocking QJ-series parts, the QJ904.31.019 and QJ554-1.31.020 (Product 9) are the most likely cross-ordering risk: both use a 32 mm rod and have similar overall lengths, but differ in bore (63 mm vs. 55 mm), stroke (250 mm vs. 248 mm), C-C (639 mm vs. 620 mm), and clevis pin (32 mm vs. 30 mm). Visual inspection of the barrel OD can separate them\u2014the 63 mm bore barrel has a noticeably larger external diameter than the 55 mm bore barrel\u2014but dimensional certification is the only reliable verification method for bulk shipment acceptance.<\/p>\n
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Installation, High-Flow Pump Verification, and Maintenance Programme for the QJ904.31.019 63 mm Bore Tractor Hydraulic Steering Cylinder<\/h2>\n
Confirm pump rated flow is \u226520 L\/min at the engine’s normal working RPM before fitting. Torque 32 mm clevis pin retention fasteners to 75\u201385 N\u00b7m. Port connections are M22\u00d71.5 at both ports; torque to 90\u2013105 N\u00b7m with new bonded seals. Fill the hydraulic reservoir to maximum; the combined circuit volume of this large-bore cylinder plus long hose runs on QJ904-class machines can absorb 1.5\u20132.0 litres of oil during initial fill, requiring a top-up after the first bleed cycle. Bleed with eight full lock-to-lock cycles at low idle. Post-bleed, increase engine speed to normal operating RPM and perform two additional lock-to-lock cycles to confirm that steering effort is consistent and no spongy feel remains at higher flow rates. Wiper seal inspection at 500-hour intervals; full seal kit replacement at 2,000 hours standard or 1,500 hours in heavy primary-tillage applications with high soil impact loading on the front axle. Chrome rod surface inspection at each annual service\u2014the 250 mm extended rod exposure is the primary maintenance focus point for this cylinder.<\/p>\n
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Factory Testing, 63 mm Bore High-Force Pressure Rig Protocol, and B2B Procurement for the QJ904.31.019 Hydraulic Steering Cylinder<\/h2>\n
The 63 mm bore and 37.4 kN extension force at rated pressure places significantly higher load on the test rig fixture than smaller bore cylinders. The factory pressure test rig for this model is rated to 30 MPa and anchored to a 500 kN reaction frame, ensuring that the 1.5\u00d7 proof load of 21 MPa at full extension (producing approximately 56 kN total force on the rig) is absorbed without fixture deflection that could introduce lateral load on the test cylinder. Proof test: 21 MPa static for 5 minutes per direction; 20 dynamic cycles at rated pressure. Internal leakage acceptance: \u22644 mL\/min (scaled for the larger 63 mm piston seal circumference). Bore taper measurement at three axial positions included in every shipment’s dimensional inspection report. Chrome rod batch: 240-hour ASTM B117. Barrel exterior: two-component epoxy primer with optional polyurethane topcoat. MOQ: 10 units; standard pallet: 24 units. Lead time: 10\u201315 working days FOB Ningbo. Custom options: 40 mm rod upgrade for maximum buckling resistance, modified port orientation, FKM seals, electroless nickel barrel coating. OEM white-label documentation in English, Spanish, Portuguese, or Korean.<\/p>\n
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Request a Quote: QJ904.31.019 Hydraulic Steering Cylinder for Tractor<\/h2>\n
Confirm the 32 mm clevis pin bore and 639 mm C-C measurement before enquiring. Bore taper and pressure test certificates supplied with every export shipment. Technical sales responds within 1 business day.<\/p>\n
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Get FOB Pricing<\/div>\n
Request Dimensional Drawing<\/div>\n<\/div>\n
MOQ: 10 units \u00a0|\u00a0 Lead time: 10\u201315 days FOB \u00a0|\u00a0 40 mm rod upgrade option available<\/p>\n<\/div>\n<\/div>\n
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Heavy-duty steering ram for 75\u2013100hp QJ904 platform tractors. 63mm bore, 35mm rod, 250mm stroke, 639mm C-C. 37.4kN extension force. Bore taper cert included, FOB Ningbo.<\/p>","protected":false},"featured_media":1555,"template":"","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":""},"product_brand":[],"product_cat":[112],"product_tag":[],"class_list":["post-1584","product","type-product","status-publish","has-post-thumbnail","product_cat-tractor-hydraulic-cylinder","first","instock","shipping-taxable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/ever-powers.com\/en_ca\/wp-json\/wp\/v2\/product\/1584","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ever-powers.com\/en_ca\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/ever-powers.com\/en_ca\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ever-powers.com\/en_ca\/wp-json\/wp\/v2\/media\/1555"}],"wp:attachment":[{"href":"https:\/\/ever-powers.com\/en_ca\/wp-json\/wp\/v2\/media?parent=1584"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/ever-powers.com\/en_ca\/wp-json\/wp\/v2\/product_brand?post=1584"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/ever-powers.com\/en_ca\/wp-json\/wp\/v2\/product_cat?post=1584"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/ever-powers.com\/en_ca\/wp-json\/wp\/v2\/product_tag?post=1584"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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