The slewing bearing is a critical component in Tadano cranes, allowing for smooth rotation and precise load movement. It consists of inner and outer rings, rolling elements, cages, and seals, capable of handling axial, radial, and moment loads. Key maintenance steps include regular inspections, proper lubrication, maintaining seal integrity, and tightening bolts. Signs of wear or damage include unusual noise, increased vibration, difficulty in movement, and visible damage. For replacement, safely support the crane, remove the old bearing, clean the mounting surface, and install the new bearing. Proper maintenance and handling ensure the crane’s safety and reliability.
A slewing bearing, also known as a turntable bearing or slewing ring, is a critical component in the Tadano crane’s mechanism. It enables the crane to rotate smoothly and accurately, ensuring the precise movement of the load. Here’s a detailed overview of its components, functions, and maintenance:
| OD | ID | Inside Bolt Holes No. | Outside Bolt Holes No. | Teeth No. | Material | Hardness | Replacement | ||
|---|---|---|---|---|---|---|---|---|---|
| Tadano z300 | 456 | 240 | 19*21mm | 10*M18 | 74 | 50Mn、42CrMo、40Cr | Above 210HB | TZ300、330、340、360 | |
| Tadano z500 | 557 | 335 | 25*22mm | 10*m16 | 91 | 50Mn、42CrMo、40Cr | Above 210HB | TZ500 | |
| unic | 455 | 238 | 19*21mm | 11*M16 | 74 | 50Mn、42CrMo、40Cr | Above 210HB | Unic 330、340、360、370 |
For more models, please contact our engineers.

If the slewing bearing shows significant wear or damage, it may need to be repaired or replaced. Here are the general steps for replacement:
The slewing bearing is a vital component for the operational efficiency of Tadano cranes. Regular maintenance, prompt repairs, and careful handling can extend its life and ensure the safety and reliability of the crane.
Expert Insights and Reliable Solutions to Your Most Common Questions.
ZZ Slewing Bearing supplies a full range of slewing bearings to meet different industrial needs:
Typical selection parameter for ZZ clients:
Load type: axial, radial, and tilting moment.
Rotation RPM: ensures long service life.
Installation space & mounting dimensions: inner/outer ring diameter, bolt circle.
Precision & rigidity requirements: critical for cranes, excavators, and robots.
ZZ engineers provide professional selection guidance according to your equipment and drawings.
ZZ Slewing Bearing selects materials for strength, wear resistance, and long-term durability:
Slewing ring: 42CrMo, 50Mn, C45N, 40CrNiMo, C48E.
Special forging spare parts: carburized/hardened steels for gear teeth (20CrMnTi, 18CrNiMo7‑6).
Corrosion resistant: SS 304, 316L, duplex stainless steel.
Surface treatments: heat treatment, quenching, carburizing, induction hardening, and surface coating(Four-Layer Packing, Strong Anti-Rust Oil, Black Oxide Treatment, Jet Black Paint Finish, Hot-Dip Galvanizing (CGL), Electro-Galvanizing (EGL), Hot-Dip Galvanizing + Paint Finish)
Correct installation with flat surfaces.
Proper lubrication using grease.
Avoid overloading or shock loads over capacity.
Monitor operating conditions regularly to prevent debris entry.
Typical factors observed by ZZ engineers:
In-stock: 3–7 days.
Custom: 2–6 weeks depending on size, load, and precision.
Warranty: 1 year
Lifetime Free Spare Parts: Glue, seals, steel ball
Yes — ZZ Slewing Bearing offers:
Detailed installation manuals.
Online engineering support.
Guidance for lubrication, maintenance, and troubleshooting solution.
Full range of materials and heat treatments for various load conditions.
High precision and strict quality inspection standards.
Engineering support before and after delivery.
Customization to exact equipment requirements.
Proven performance in cranes, excavators, robotics, wind turbines, and heavy machinery etc.
ZZ Slewing Bearing (Shanghai) Co., Ltd
Leading Slew Drive & Slewing Bearing Manufacturer in China.
ZZ products are applied globally in solar tracking systems, wind power systems, satellite communications, and numerous other globally connected industries.

