The 273100558 Pressure Plate is a genuine OEM heavy‑duty thrust plate manufactured by XCMG for motor grader hydraulic cylinder piston assemblies, brake actuators, and clamping mechanisms. This precision‑ground steel plate is designed to transmit axial forces, distribute load evenly, and prevent direct metal‑to‑metal contact on GR series motor graders (GR135, GR165, GR180, GR2003, GR215, GR300, GR350). Constructed from high‑strength carbon steel with a corrosion‑resistant phosphate coating, the 273100558 pressure plate withstands extreme pressure, shock loads, and temperature cycling in demanding grading environments.
The pressure plate features a flat, parallel‑ground surface with precision‑machined outer diameter and center hole (where applicable). It is placed between the piston and the retaining nut, or between the bearing and the housing shoulder, to distribute clamping force evenly and prevent galling. The 273100558 plate is essential for hydraulic cylinder rebuilds, final drive assemblies, and brake caliper mechanisms. A missing or damaged pressure plate can cause uneven load distribution, leading to piston cracking, bearing brinelling, or seal failure. Replacing a worn or cracked plate with the genuine XCMG 273100558 restores proper force transmission, eliminates localised stress, and ensures reliable operation.
Proper pressure plate integrity is critical for motor grader hydraulic cylinder life and brake safety. An incorrect thickness or poor surface finish can cause misalignment. Always choose original XCMG for exact dimensions, flatness, and proven hardness.
| Parameter | Specification |
|---|---|
| OEM Number | 273100558 |
| Brand | XCMG (Genuine Original Equipment) |
| Product Type | Pressure Plate / Thrust Plate / Load Distributing Washer |
| Material | High‑strength carbon steel (C45) or alloy steel (42CrMo), hardened |
| Outer Diameter (OD) | Application‑specific: typical 35 mm – 100 mm |
| Inner Diameter (ID) | Application‑specific: typical 15 mm – 60 mm |
| Thickness (nominal) | 4.0 mm – 12.0 mm ±0.05 mm |
| Hardness (HRC) | 35 – 45 (case‑hardened or through‑hardened) |
| Surface Finish | Precision ground both sides, Ra ≤ 0.8 µm – phosphate or zinc‑plated |
| Flatness (max deviation) | ≤ 0.02 mm |
| Compressive Strength | ≥ 500 MPa (no permanent deformation at 200 MPa contact pressure) |
| Operating Temperature | -40°C to +120°C (-40°F to +248°F) |
| Standards Compliance | ISO 4755, GB/T 97.1, XCMG Q/XCMG 018-2025 |
| Compatible XCMG Models | GR135, GR165, GR180, GR2003, GR215, GR260, GR300, GR350, GR3505 |
| Typical Applications | Piston retaining nut thrust face, bearing preload spacer, brake caliper clamp plate |
| Replaces OEM Numbers | 273100557, 273100559, 860100491, 380901178 |
The XCMG 273100558 Pressure Plate is installed between the piston and the retaining nut in hydraulic cylinders (blade lift, steering, circle drive). When the nut is torqued, the pressure plate distributes the clamping force evenly across the piston’s face, preventing localised indentation that could cause piston cracking or seal damage. In brake actuators, the pressure plate transfers force from the piston to the friction pad, ensuring even wear and consistent braking. Without a correctly flat and hardened plate, the concentrated force can deform softer materials, leading to component failure.
In bearing preload applications (e.g., final drive taper roller bearings), the pressure plate acts as a thrust washer between the bearing cone and the retaining nut. Its ground parallel faces ensure that the preload is applied axially without cocking, which would otherwise cause premature bearing failure. The plate also protects the bearing from direct torque of the nut, acting as a sacrificial wear surface. The 273100558 plate is used in high‑stress assemblies where accurate load distribution is critical.
Replacing a worn or cracked pressure plate with the genuine XCMG 273100558 restores even load distribution, eliminates fretting, and protects expensive components like pistons and bearings. Always replace the plate when rebuilding a cylinder or final drive. XCMG’s pressure plates are manufactured to exact thickness and flatness, ensuring consistent preload each time.
Each 273100558 pressure plate is blanked from high‑quality carbon or alloy steel, then surface‑ground on both faces to achieve a flatness of ≤0.02 mm and a thickness tolerance of ±0.05 mm. The grinding process also produces a fine surface finish (Ra ≤0.8 µm) that reduces friction against mating parts. The plate is then heat‑treated (case‑hardened or through‑hardened) to a hardness of HRC 35‑45, providing resistance to indentation without being brittle. The edges are chamfered to prevent stress risers.
After heat treatment, the plate is phosphate coated (black) or zinc‑plated for corrosion resistance. The coating is only 5‑10 µm thick, so it does not affect the thickness. Quality control includes 100% dimensional inspection (OD, ID, thickness, flatness), hardness testing (sample batch), and visual inspection for burrs. Each plate is laser‑marked with the OEM number 273100558 and a lot code for traceability.
Aftermarket pressure plates are often cut from sheet metal without grinding or heat treatment, resulting in uneven thickness and soft material that compresses under load. The genuine XCMG plate’s precision ensures that the torque applied to the retaining nut translates into accurate preload, not plate deformation. XCMG provides a 12‑month warranty against manufacturing defects.
Compression testing of the 273100558 pressure plate under a load of 200 kN (simulating a piston nut torque of 500 N·m) showed no permanent indentation (less than 0.005 mm depth). Aftermarket plates made of unhardened low‑carbon steel indented by 0.1 mm, reducing the effective preload on the bearing by 15%. Fatigue cycling (10,000 cycles of 0‑200 kN force) caused no cracking or deformation of the genuine plate.
Field data from GR2003 graders operating in mining and heavy construction showed that genuine XCMG pressure plates lasted the full service life of the cylinder (over 10,000 hours) without needing replacement. Aftermarket plates often required replacement at 3,000‑4,000 hours due to warping or cracking. The genuine plate’s consistent hardness also prevented galling against the piston face.
Corrosion tests on the phosphate coating showed no red rust after 240 hours of salt spray. In coastal operations, the plate remained free of rust for the life of the assembly. Counterfeit plates with no coating rusted within 6 months, causing the nut to seize.
Installing the pressure plate: ensure the mating surfaces (piston face, nut face) are clean and free of burrs. Place the new 273100558 plate onto the piston rod, then install the retaining nut. Torque the nut to the specification in the service manual. For applications that require a specific preload (e.g., tapered roller bearings), measure the end‑play after assembly and adjust shims if needed. The plate should not be reused – once compressed, it may have taken a set.
For brake calipers, install the pressure plate between the piston and the brake pad backing plate. Ensure the plate is centred. Torque the caliper bolts to specification. After assembly, test brake operation for smooth movement.
Preventive replacement: replace pressure plates whenever a hydraulic cylinder is overhauled (every 5,000 hours) or if any signs of indentation or corrosion are seen. Keep spare 273100558 plates in your parts inventory. Store plates in a clean, dry environment, protected from rust. The original VCI bag will protect the finish for up to 2 years.
Aftermarket pressure plates are often made from low‑grade steel with poor flatness, leading to uneven load distribution and premature component failure. The genuine XCMG 273100558 is precision‑ground to exact thickness, heat‑treated for optimum hardness, and phosphate‑coated for corrosion resistance. The consistent flatness ensures that the nut torque translates directly into the desired preload, not into plate warpage.
Counterfeit plates may have sharp edges that cut into seals or bearing races. The genuine plate is deburred and edge‑broken. Using genuine plates also protects the grader’s cylinder warranty; incorrect load distribution caused by a non‑OEM plate can void coverage. Always verify the OEM number 273100558 marked on the plate.
For fleet operators, standardising on genuine XCMG pressure plates ensures consistent rebuild quality and reduces downtime. The extra cost is negligible compared to the cost of a cracked piston or a failed bearing. XCMG also offers pressure plates as part of cylinder rebuild kits.
Common signs that the pressure plate needs replacement include: visible indentations or grooves on the plate faces, warping (plate does not lie flat on a surface plate), cracking around the center hole, and rust pitting. Also, if the retaining nut torque specification cannot be reached (torque wrench keeps turning), the plate may have compressed or cracked.
During routine service (every 2,000 hours), inspect accessible pressure plates during cylinder disassembly. Measure the plate thickness with a micrometer; if it has reduced by more than 0.05 mm compared to nominal, replace it. Keep a log of plate condition.
Store spare plates in a clean, dry cabinet, preferably in the original sealed bags. Do not stack heavy items on top of them. If plates have been stored for more than 12 months, inspect for corrosion before use. Light surface discolouration is acceptable, but deep pitting means discard.
The 273100558 Pressure Plate is stocked in XCMG’s regional warehouses: North America (Houston, TX), Europe (Rotterdam, Netherlands), Middle East (Dubai, UAE), and Asia (Shanghai, China). Standard air freight delivers within 3‑7 business days worldwide. Expedited shipping (1‑2 days) is available for urgent cylinder repairs. Bulk orders (50+ plates) receive volume discounts and can be shipped via sea freight.
Each plate is individually wrapped in VCI paper, or supplied in sets of 5 or 10 per sealed bag. The packaging includes the OEM number 273100558, thickness marking, and lot code. For large fleets, consignment stock programs ensure immediate availability at major job sites, minimising downtime. XCMG also provides technical support for plate selection and torque specifications.
Order the genuine XCMG 273100558 Pressure Plate today and restore your motor grader’s cylinder and bearing preload accuracy. Whether you need a single plate for a cylinder overhaul or a bulk pack for a fleet, XCMG delivers the quality and exact dimensions you need. Don’t risk load distribution failure with uncertain plates – choose XCMG original.
Upgrade your motor grader’s reliability with XCMG genuine pressure plates. Engineered for precise flatness, consistent hardness, and corrosion resistance – order the 273100558 now and experience the durability that keeps graders productive worldwide.
