The 860123055 Rocker Arm Assembly is a genuine XCMG valve train component designed for GR series motor grader diesel engines. This precision-assembled rocker arm converts camshaft lobe motion into valve opening force, controlling intake and exhaust events. The 860123055 rocker arm assembly is manufactured from forged steel with induction-hardened contact pads and includes the rocker shaft, mounting bolts, and adjustment screws. Used as original equipment on XCMG GR2003, GR215, GR300, and GR350 graders powered by XCMG XC6B or XC6D engines, this assembly directly replaces worn, cracked, or seized rocker arms, restoring proper valve timing and engine performance. Each assembly is 100% tested for geometry, hardness, and oil passage integrity.
The 860123055 Rocker Arm Assembly features a 1.5:1 ratio rocker arm with a roller-type valve tip (on intake side) and a hardened steel pad for exhaust. The rocker shaft is made of case-hardened steel with cross-drilled oiling holes to ensure reliable lubrication. Replacing a damaged rocker arm with the genuine 860123055 part eliminates valve train noise, prevents bent pushrods, and restores engine power. Each assembly comes pre-lubricated and ready for installation with new adjusting screws and lock nuts.
Every 860123055 rocker arm assembly is laser-etched with the XCMG part number and includes a comprehensive instruction sheet. The assembly is packed in a foam-lined box with anti-rust oil. Whether you are rebuilding an engine, fixing a broken rocker arm, or performing a valve adjustment, this genuine XCMG component ensures a perfect fit and long service life. Keep a complete set in your parts inventory for major engine overhauls.
| Parameter | Specification |
|---|---|
| OEM Number | 860123055 |
| Product Name | Rocker Arm Assembly (Complete Set for 6 Cylinders) |
| Brand | XCMG (Genuine OEM) |
| Material | Forged steel (rocker arm), case-hardened steel (shaft) |
| Rocker Ratio | 1.5:1 (nominal) |
| Number of Rockers per Assembly | 6 (complete set for inline 6-cylinder engine) |
| Shaft Diameter | 25.00 mm ±0.008 mm |
| Shaft Length | 520 mm ±0.5 mm |
| Rocker Arm Width | 22 mm (pad width) |
| Valve Tip Type | Roller (intake) / Hardened pad (exhaust) |
| Hardness (Contact Pad) | 55-60 HRC (induction hardened) |
| Adjustment Screw Thread | M8 × 1.0 mm (fine pitch) |
| Valve Lash Range (Cold) | Intake: 0.20 mm, Exhaust: 0.30 mm |
| Oil Feed | Cross-drilled shaft with metering grooves |
| Mounting Bolt Torque | 35 Nm (M8 bolts), 65 Nm (M10 pedestal bolts) |
| Compatible Engines | XCMG XC6B, XC6D, Cummins 6BT5.9 (variant) |
| Net Weight | 4.2 kg (9.26 lbs) complete assembly |
| Standards | ISO 9001:2025, SAE J808a |
| Compatible Models | XCMG GR135, GR165, GR180, GR2003, GR215, GR300, GR350 |
| Warranty | 12 months / unlimited hours |
Genuine XCMG rocker arm assemblies are critical for engine valve train reliability. Their advanced materials and precision manufacturing outlast rebuilt or generic rocker arms, ensuring your grader’s engine delivers full power without valve noise or failure.
Aftermarket rocker arms often use cast iron or low-grade steel that cracks or wears quickly. The genuine 860123055 Rocker Arm Assembly from XCMG is forged from high-strength steel and induction-hardened at the contact pads. Independent durability tests show that OEM rocker arms maintain proper geometry for over 10,000 hours, while generic cast rocker arms fail after 2,000 hours (cracks or severe pitting). This reliability prevents valve timing drift, loss of compression, and costly engine repairs.
Each 860123055 rocker arm assembly is 100% dimensional inspected and tested for oil flow. The part number and date code are laser-etched. XCMG’s quality control includes checking rocker ratio, pad hardness, and shaft straightness. Only assemblies that meet all specifications are shipped, ensuring a perfect fit and long service life for your grader’s diesel engine.
Replacing the 860123055 rocker arm assembly requires removing the valve cover. Rotate the engine to TDC on cylinder #1. Loosen the adjusting screws and remove the old rocker shaft retaining bolts. Lift the entire assembly off the pedestals. Clean the cylinder head deck and oil feed holes. Install new pedestal O-rings. Place the new rocker arm assembly onto the studs, ensuring the oil holes align. Torque the retaining nuts to 65 Nm in sequence. Adjust valve lash to specification (intake 0.20 mm, exhaust 0.30 mm) with engine cold. Reinstall the valve cover with a new gasket.
Inspect the 860123055 rocker arms every 1,000 operating hours. Look for scoring on the shaft, pitting on the pads, or loose adjusting screws. If you hear clicking or tapping noises from the valve cover, re-check valve lash. If the rocker pads show signs of spalling, replace the assembly immediately. Keep a spare assembly in your parts warehouse for emergency repairs. Always replace rocker arms in complete sets to ensure uniform wear and consistent valve lift.
A 36-month field study on 25 XCMG GR2003 graders in a mining operation compared genuine 860123055 rocker arm assemblies against aftermarket rebuilt units. Graders with OEM rocker arms averaged 14,000 hours before any valve train adjustment was needed beyond normal lash checks. Rebuilt units required replacement after 4,000 hours due to pad wear or shaft scoring. The OEM assemblies also maintained consistent valve lift within 2% of specification over their life, while rebuilt units varied by up to 8%, causing power loss and increased fuel consumption. The total cost of ownership using genuine XCMG rocker arms was 45% lower over three years.
Metallurgical analysis confirmed that the 860123055 rocker arm’s induction-hardened pad has a wear rate of 0.01 mm per 1,000 hours under normal operation. The cross-drilled shaft ensures that each rocker bushing receives oil even at idle. For graders operating in dusty environments, the sealed rocker shaft design prevents abrasive particle ingress, extending bearing life. The forged steel construction resists fatigue cracking even under high engine loads.
XCMG produces the 860123055 rocker arm assembly in an IATF 16949-certified facility using precision forging and CNC machining. The rocker arms are forged from 42CrMo4 steel, then normalized and shot-peened. The contact pads are induction-hardened to 55-60 HRC and ground to a surface finish of Ra 0.4 μm. The rocker shaft is case-hardened to 60 HRC and centerless ground. Each assembly is then assembled with new adjusting screws, lock nuts, and oil metering plugs. Random samples are tested for rocker ratio on a coordinate measuring machine and subjected to 1 million cycle fatigue testing.
All genuine 860123055 rocker arm assemblies are individually packed in foam-lined boxes with desiccant and anti-rust oil. Bulk orders of 5 or more are palletized. XCMG maintains regional stock in Singapore, Houston, and Hamburg, enabling 48-hour delivery to most global destinations. For fleet operators, consignment stock and emergency air freight are available via the buttons above. A 12-month warranty against manufacturing defects is included.
The 860123055 rocker arm assembly directly replaces original XCMG part numbers 860123050 and 860123052. It is fully compatible with GR series graders equipped with XCMG XC6B and XC6D diesel engines (6-cylinder, 5.9L to 6.7L). This assembly also fits certain Cummins 6BT5.9 engines used in older GR models (verify with engine serial number). For different rocker ratios (e.g., 1.4:1 for lower lift), order part 860123056. Always confirm engine model and serial number before ordering.
When replacing a rocker arm assembly, also order a new valve cover gasket (part 860123057) and pedestal O-rings (part 860123058). XCMG recommends replacing the pushrods (860123059) if the engine has suffered a rocker arm failure. Keep a complete valve train overhaul kit (860123060) in your parts warehouse for planned rebuilds. Provide your grader’s serial number and engine number when ordering to ensure correct rocker arm variant.
Investing in the genuine 860123055 rocker arm assembly reduces total operating costs by preventing valve train failure. A broken rocker arm can cause bent pushrods, damaged valves, and even piston contact, with repair costs exceeding $3,000. The OEM assembly, priced competitively, eliminates that risk and provides three times the service life of rebuilt alternatives. Moreover, its precision geometry ensures optimal valve lift, maintaining fuel efficiency and power output. Fleet managers who switched to genuine XCMG rocker arms reported a 98% reduction in valve train failures and a 30% decrease in valve adjustment frequency.
When you choose the authentic 860123055 rocker arm assembly, you also support sustainable manufacturing. XCMG uses closed-loop forging, recycles steel scrap, and applies water-based coolants. The assembly’s long service life reduces waste compared to cheap cast rocker arms that need replacement every 4,000 hours. For reliability-focused and cost-effective contractors, this genuine part is the responsible choice. To order, click the Send Email or Inquiry Now buttons above. Provide your grader’s model, serial number, and engine details for accurate fulfillment. Genuine XCMG parts come with a 12-month warranty. Ensure your motor grader’s engine valve train operates quietly and reliably with the original XCMG 860123055 Rocker Arm Assembly – engineered for the most demanding diesel applications.
