Maintenance Guide

Failure & Troubleshooting

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.

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.

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.

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.


General Questions

Our manufacturing size range from 240mm to 2400mm, measuring diameter from outside ring.

We make all the production processes from grinding, drilling, heat treatment and finishing in house.

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

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

It mainly depends on raw material availability of the lead time will be from 45 days to 75 days in general. For OEM products and popular items, we always have stock on hand, the lead time will far be shorten to 3-7 days.

The MOQ is 2pcs per item.

Kyoei Brand will only supply to OEM business at the moment. Moreover, we offer customized branded packing at our customers request.

We are expertise in Slewing Rings in past 10 years. Since 2020, we provide some related parts, like undercarriage parts, track links, track shoes, buckets, seal kit and so on.

Related to brand new products

These will not affect the quality and lifetime.

Grease is being injected before delivery. And, 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.

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

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.

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.

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.

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 the raceway. Please go to installation guide for more details.