

The genuine XCMG 273100573 Worm Shaft is a precision‑ground, case‑hardened power transmission component designed for motor grader circle rotation drives and steering gearboxes. This OEM 273100573 worm shaft meshes with the matching worm gear (273100564) to convert rotational input into powerful, backlash‑controlled angular motion for blade circle positioning and articulation control. Manufactured from high‑alloy carburizing steel with ground tooth flanks and superfinished journals, the XCMG worm shaft delivers smooth, efficient torque transfer under extreme grader loads.
The 273100573 worm shaft is used on XCMG GR135, GR165, GR180, GR215, GR260, GR300, and GR350 motor graders. It mounts inside the circle drive housing or steering gearbox, supported by tapered roller bearings at both ends. The multiple‑start worm thread ensures high reduction ratio with self‑locking capability, preventing blade drift during grading.
A worn or pitted worm shaft causes erratic circle rotation, steering play, and accelerated wear of the mating gear. Replacing damaged shafts with genuine XCMG 273100573 restores factory precision and eliminates backlash, ensuring accurate blade positioning and longer component life.
| Parameter | Specification |
|---|---|
| OEM Number | 273100573 |
| Brand | XCMG (Genuine Original Equipment) |
| Product Type | Worm Shaft / Worm Screw – Circle Drive / Steering Gear |
| Material | Case‑hardening alloy steel (20MnCr5 / SAE 8620) |
| Heat Treatment | Carburizing + quenching + tempering (case depth 0.8‑1.2 mm) |
| Surface Hardness (Tooth Flanks) | 58‑62 HRC |
| Core Hardness | 28‑35 HRC |
| Number of Thread Starts | 3 (triple‑start worm) for high reduction |
| Module (Axial) | 4.0 (ISO metric) |
| Lead Angle | 21°48′ at pitch diameter |
| Overall Length | 185 mm ±0.5 mm |
| Journal Diameter (Bearing Seats) | 30 mm / 25 mm (ground, tolerance h6) |
| Tooth Profile Accuracy | DIN 3975 Grade 6 (ground) |
| Runout (TIR) | ≤ 0.02 mm |
| Maximum Input Torque | 600 Nm (4,450 lb‑in) continuous |
| Operating Temperature | -40°C to +130°C (with EP gear oil) |
| Lubrication | SAE 80W‑90 or XCMG worm drive extreme pressure oil |
| Compatible Models | XCMG GR135, GR165, GR180, GR215, GR260, GR300, GR350 motor graders |
| Superseded Part Numbers | 273100478, 273100509, 273100600 |
The 273100573 worm shaft is the primary input element of the grader’s circle drive. Connected to a hydraulic motor or manual crank, it rotates and drives the worm gear, which turns the entire blade circle.
Because worm drives are self‑locking, the 273100573 prevents the blade from back‑driving under load, eliminating unwanted angle drift during grading. This characteristic is essential for maintaining a consistent blade slope and flat grade.
In steering applications, the worm shaft provides progressive, precise steering effort. Worn shafts cause free play, reducing operator confidence and increasing fatigue. Replacing a worn part with genuine 273100573 restores crisp control.
Each 273100573 worm shaft begins as a forged billet of 20MnCr5 alloy steel. After rough turning, the worm thread is hobbed on a CNC worm milling machine, followed by stress relieving.
The shaft then undergoes gas carburizing to a case depth of 1.0 mm, creating a hard, wear‑resistant outer layer while retaining a tough ductile core. The journals are precision ground to h6 tolerance, and the thread flanks are profile‑ground to DIN 3975 Grade 6 accuracy.
XCMG performs magnetic particle inspection for cracks and uses a double‑flank gear rolling tester to verify tooth contact pattern. Each worm shaft is serialized and test‑meshed with a master gear to confirm backlash below 0.05 mm.
Replacing a worn worm shaft requires removing the circle drive housing or steering gearbox. Drain the gear oil, remove the cover, and extract the bearings and old shaft. Clean all components thoroughly.
Install new tapered roller bearings onto the 273100573 shaft. Apply assembly oil to the journals. Position the shaft into the housing, ensuring the worm aligns with the worm gear. Adjust bearing preload according to the service manual (typically 0.10‑0.20 mm axial play).
Check tooth contact pattern using marking compound. Correct gear mesh by adjusting housing shims. Fill with fresh XCMG worm drive oil. Run the circle rotation slowly to distribute oil before full load.
Classic symptoms include: excessive free play in blade circle rotation (more than 15 mm measured at the blade tip), ratcheting or clunking noise when turning the steering wheel, and metal particles in the gear oil.
Visible pitting or spalling on the worm thread flanks, uneven wear patterns, or scoring on bearing journals indicate the need for immediate replacement. Always replace the worm gear together with the 273100573 shaft for optimal meshing.
XCMG recommends inspecting the worm shaft and gear every 2,000 operating hours by checking rotational backlash and oil condition. Replace the 273100573 worm shaft every 6,000 hours for standard road grading.
For graders working in heavy ripping or frequent cross‑slope grading, shorten replacement to 4,000 hours. Change gear oil every 1,000 hours with EP 80W‑90. Contaminated oil drastically accelerates worm wear.
Keep the breather plug clean to prevent water ingress. If the circle drive housing has been flooded, inspect the worm shaft for rust immediately. Using genuine XCMG 273100573 ensures correct metallurgy and heat treatment for maximum durability.
Aftermarket worm shafts often use cheaper steel (e.g., 1045) with simple induction hardening that lacks depth. Genuine XCMG 273100573 uses fully carburized 20MnCr5, providing a wear‑resistant case and tough core that resists fatigue.
Counterfeit shafts may have poor thread accuracy, causing rough operation and rapid gear wear. OEM shafts are profile‑ground and inspected to Grade 6, ensuring smooth, quiet rotation.
XCMG backs every genuine worm shaft with a 12‑month warranty. Stocked in Houston, Rotterdam, Dubai, and Shanghai. Air freight 3‑7 days, emergency 24‑48 hour shipping available. Protect your grader’s circle drive – order genuine 273100573 today.
The 273100573 worm shaft is the heart of your grader’s blade control system. Don’t tolerate play, noise, or erratic circle rotation. Replace worn shafts proactively and restore factory‑fresh steering and circle response. Keep a genuine XCMG worm shaft in your parts inventory for immediate installation.
Upgrade your motor grader’s reliability with precision‑ground, case‑hardened XCMG quality. Order the 273100573 Worm Shaft now and experience smooth, backlash‑free circle rotation for thousands of productive hours in the toughest grading conditions.