Installation Guide
  • Bolts mounting
  • Backlash, Soft Zone
  • Grease filling
Maintenance Guide
  • Grease refill
  • Seal replacement


General Questions
  • What is the size range of Slewing Rings manufacturing in Kyoei?

    Our manufacturing size range outside diameter of Slewing Rings from 240mm to 2400mm.

  • What manufacturing process of Slewing Ring Kyoei does?

    Except the outsourcing of the quality forged raw material, we do all processes from grinding, drilling, heat treatment and finishing in house.

  • What is the lifetime of Kyoei’s Slewing Rings?

    Most of the customers experienced Kyoei’s Slewing Rings can last at least for more than 3 years in general assuming with correct installation, maintenance and normal working conditions. Meanwhile, we also got some feedbacks from customers that many of our Slewing Rings are being used for over 10 years.

  • How long is the warranty period?

    1 year or 2000 working hours from the shipping date. (Bill of lading date for International delivery or invoice date for Domestic delivery)

  • What is the lead time for an order?

    It mainly depends on raw material availability, lead time will be from 45 days to 75 days in general. For OEM products and some popular items, we always have stock on hand available, the lead time will then be 3 days from stock.

  • What is the minimum of quantity per order?

    MOQ 2pcs per item.

  • Is all the packaging under Kyoei Brand?

    Unfortunately, Kyoei Brand will only supply to OEM business at the moment. We are more than happy to customize brand packaging for our customers and are also welcome to have your own brand printed with our products.

  • Any other products are available besides Slewing Rings in Kyoei?

    We are expertise in Slewing Rings in past 10 years. Having said that, since Year 2020, some related parts like undercarriage parts including track links and track shoes, also other parts such as buckets, seal kit are newly released. Please do not hesitate to send us enquiries.

Related to brand new products
  • Will scratches or rusts affect the quality?

    It will not affect the quality and lifetime.

  • Is grease being pre-injected?

    Yes, grease is being injected before delivery, however grease is required to refill in certain period of time in order to have the best performance and maintenance. Please go to the maintenance guide for more details.

  • Found the Grease nipple is missing when the product arrives?

    Grease nipple does not come with Kyoei’s Slewing Rings.

  • How long can the new Slewing Rings be stored?

    Our Slewing Rings are all wrapped with anti-rust paper, it can be stored in door for more than two years. Rusts will not affect the quality of the slewing rings but not good in appearance. Besides, please also check grease level before use.

  • There are some noises after installation?

    Our Slewing Ring are having quality checked and tested before it become a finished product, if noise occurs after installation, please see “troubleshooting section” in this FAQ for more details and solutions.

  • About installation marks

    We have 1 to 3 teeth that painted in GREEN color, to indicate where the smallest inner diameter is (internal gear) or where the largest outer diameter is (external gear). These marks are used to check the clearance while installing new slewing rings. Please go to installation guide for more details.

  • About soft zone

    We have a ‘S’ mark for soft zone, where a gap between the beginning and the end of raceway hardening process. It is the weakness zone of raceway. Please go to installation guide for more details.

Failure & Troubleshooting
  • Teeth broken

    Incorrect Pinion gear. This often happens when replacing with aftermarket pinion gear, which the pressure angle may not be matched with genuine design. All Kyoei’s Slewing Rings are made based on genuine drawings or genuine samples. It is highly recommended to have a genuine pinion gear installed/replaced, or to ensure the pressure angle is correct and matched when purchasing it from the aftermarket.

  • Noise when the Slewing Ring is turning

    With different working conditions, the mounting frame of machine may become twisted, blended or not as flat as the original. It often happens in old machines. This deviation will cause noise when the Slewing Ring is turning. If you found there are two specific spots are having noise or ‘click’ sound, like 180 degrees of the opposite side, it would be very likely that the deviation problem between the Slewing Ring and the mounting frame. Please go to mechanic or repair shops nearby, do the measurement and then the problem can be easily solved by filling casting component.

  • Slewing Ring is not able to turn/swing

    Run out of grease. When the raceway is dried out of grease, plastic spacer between steel balls will be burnt out. Meanwhile, teeth broken can also cause the Slewing Ring stuck. Please go to the maintenance guide for more details.

  • Slewing Ring is too loose to turn

    If you found the Slewing Ring is too loose to turn, please go to the maintenance guide and look for the clearance measurement method, which is the method that all OEM factories are using. Kyoei’s Slewing Rings clearance is either based on JIS or genuine part standards. If the measurement is out of the range, you may consider to replace with a new ring. If it is a new ring, please report to our sales team, we will response to it promptly.