The 803402429 Lip Seal B55×72×8 is a genuine OEM rotary shaft seal manufactured by XCMG for motor graders and heavy construction equipment. This precision‑elastomeric seal, also known as a radial lip seal or oil seal, provides a leak‑tight barrier between rotating and stationary components, preventing loss of lubricant and ingress of contaminants on XCMG GR series motor graders. Manufactured from premium nitrile rubber (NBR) with a integrated garter spring, the 803402429 seal is designed to withstand high shaft speeds, extreme temperatures, and abrasive dust in demanding grading environments.
The B55×72×8 dimensions indicate a 55 mm bore (shaft diameter), 72 mm outer diameter (housing bore), and 8 mm thickness. This lip seal is a direct replacement for worn or leaking seals on XCMG GR135, GR165, GR180, GR215, GR260, GR300, and GR350 motor graders. Typical applications include front wheel hub seals, final drive pinion seals, transmission output shafts, and circle drive gearbox input shafts.
A damaged or hardened lip seal allows oil to leak onto brakes or the environment, and permits dust and water to enter bearings. This leads to rapid wear, overheating, and eventual component failure. Replacing a faulty seal with the genuine XCMG 803402429 restores leak‑free operation and protects your grader’s critical rotating assemblies.
| Parameter | Specification |
|---|---|
| OEM Number | 803402429 |
| Brand | XCMG (Genuine Original Equipment) |
| Product Type | Rotary Shaft Lip Seal (Single Lip with Garter Spring) |
| Nominal Dimensions | 55 mm (ID) × 72 mm (OD) × 8 mm (width) |
| Material – Body | Nitrile Butadiene Rubber (NBR) 70 Shore A |
| Material – Spring | Carbon spring steel (zinc plated), 0.6 mm wire diameter |
| Hardness (rubber) | 70 ± 5 Shore A (ISO 7619) |
| Tensile Strength | ≥ 14 MPa (NBR rubber) |
| Elongation at Break | ≥ 300% |
| Maximum Shaft Speed | 15 m/s (4,500 rpm on 55 mm shaft) |
| Maximum Pressure Differential | 0.05 MPa (0.5 bar) – borderline vented |
| Operating Temperature Range | -35°C to +110°C (continuous), 120°C peak |
| Shaft Hardness Required | ≥ 45 HRC, ground finish Ra ≤ 0.4 μm, Rz ≤ 2.5 μm |
| Housing Bore Finish | Ra ≤ 2.0 μm, chamfered entry |
| Standards | ISO 6194-1, DIN 3760 type A |
| Compatible Models | XCMG GR135, GR165, GR180, GR2003, GR215, GR260, GR300, GR350 |
| Applications | Wheel hub seals, final drive pinion seals, transmission output, circle drive input, axle shaft seals |
The XCMG 803402429 Lip Seal B55×72×8 is a vital sealing component for gearboxes, wheel hubs, and final drives. It retains oil or grease inside the housing while excluding dust, water, and abrasive particles. On an XCMG motor grader, a single seal failure can cost thousands in bearing replacement and downtime.
Typical applications include the front wheel hub seal, where the seal prevents wheel bearing grease from leaking onto the brake disc. In the circle drive gearbox, the input shaft seal keeps gear oil inside while preventing dirt from migrating up the shaft. The output seal on the transmission also uses the B55×72×8 size on many GR series units.
When the lip seal becomes hard, cracked, or the spring loses tension, oil begins to leak. Leaking oil on brakes reduces stopping power; leaking oil on the ground is an environmental hazard and leads to low oil levels and bearing starvation. Replacing a faulty seal with the genuine 803402429 restores the original sealing performance.
Each 803402429 lip seal is molded in a high‑precision cavity die using premium NBR compound with excellent oil and abrasion resistance. The sealing lip is ground to a precise angle of 38° (standard) and a contact band width of 0.15‑0.25 mm. The garter spring is wound from stainless steel wire and custom‑sized to provide uniform radial force around the entire circumference.
After molding, the seal is 100% visually inspected for flash, voids, and lip deformation. Random samples are tested for low‑temperature flexibility (‑35°C no cracking) and oil immersion (72h at 100°C in gear oil, volume swell ≤ 12%). The spring force is measured on a tensile tester, and any deviation beyond ±10% rejects the batch.
XCMG’s quality system ensures that every 803402429 seal meets ISO 6194-1 and DIN 3760 standards. The seal is packed in individual anti‑adhesion bags to prevent sticking during storage. The outer metal case (if applicable) is coated with a rust‑preventive oil; all‑rubber versions are protected by talc coating.
Proper installation of the lip seal 803402429 is essential for leak‑free operation. Before installation, inspect the shaft for grooves, nicks, or rust. If damaged, the shaft must be repaired or replaced. The shaft must have a lead‑in chamfer (15° minimum) and a surface finish of Ra ≤ 0.4 μm.
Lubricate the seal lip and shaft with clean oil or grease before assembly. Use a seal installation sleeve to prevent the lip from rolling over or being cut by the shaft edge. Press the seal squarely into the housing bore using a seal driver that contacts the outer metal case (never the lip area). The seal should be flush with the housing face, or recessed per manual spec.
Do not reuse a removed seal – the lip will have taken a set and the spring may be damaged. Always replace the seal when servicing related components (bearings, shafts). After installation, run the assembly at low speed and check for immediate leakage. If the seal leaks within the first hour, it was likely damaged during installation.
Aftermarket seals often use cheaper nitrile compounds with lower oil resistance or poorly controlled lip geometry. They may have springs made from plain carbon steel that rusts, reducing spring force. The genuine XCMG 803402429 uses a corrosion‑resistant spring and premium NBR that maintains flexibility for years.
Counterfeit lip seals sometimes have an incorrect lip angle or mould flash that causes immediate leakage. The 803402429 has a cleanly moulded lip and is 100% inspected. Genuine seals are packaged in XCMG branded bags with a QC sticker and date code. Always verify the branding and avoid bargains – a leaking seal will cause more damage than the cost difference.
XCMG offers a 12‑month warranty against manufacturing defects. Using genuine seals protects your machine’s warranty and ensures reliable sealing in the harsh grading environment. Don’t risk oil loss and bearing failure – choose the 803402429 genuine lip seal.
Common signs that the lip seal 803402429 needs replacement: oil spots on the inside of the wheel rim, oil on the floor under the grader, grease contamination of brake pads, and oil level drop in gearboxes or hubs. Also, visible cracking or hardening of the rubber can be seen during inspection.
Preventive replacement is recommended every 5,000 operating hours or during any major overhaul of wheel ends or gearboxes. The cost of a seal is small compared to the cost of bearing replacement if the seal fails. Always replace seals in pairs (left and right wheel hubs) for even reliability.
Store spare seals in a cool, dry, dark place away from ozone sources (electric motors). Keep them in their sealed bags; do not wash with solvent. Shelf life properly stored is 5 years from manufacture date.
The 803402429 Lip Seal B55×72×8 is stocked in XCMG regional warehouses in North America (Houston), Europe (Rotterdam), Middle East (Dubai), and Asia (Shanghai). Standard air freight delivers within 3‑7 business days worldwide. Expedited shipping (1‑2 days) is available for urgent repairs.
Each seal is supplied in a sealed plastic bag with a part number label. Bulk orders (25+ pieces) receive volume discounts and can be shipped via sea freight. For large fleets, consignment stock programs ensure immediate availability and reduced downtime.
Order the genuine XCMG 803402429 Lip Seal B55×72×8 today and stop oil leaks on your motor grader. This seal is a critical component for wheel hubs, final drives, and gearboxes. Keep spares in your service inventory and always replace with genuine XCMG parts.
Upgrade your motor grader’s reliability with the XCMG genuine lip seal. Engineered for precision, heat resistance, and leak‑free performance – order now and experience the quality that keeps your grader productive and clean.
