Time is money, so when it comes to caster maintenance in the workplace, it’s far more cost effective to be proactive than reactive: a proactive program that avoids the costly repair and maintenance issues associated with equipment breakdowns.

Maintaining casters and wheels requires a disciplined maintenance program that routinely inspects all aspects of its functionality. Casters make work easier, and routine maintenance generally is an easy task. There are three critical areas that require routine inspection: visual inspection of the caster body; the swivel head mechanism; and the wheel.

Look at What's Rattling
Casters that allow carts and equipment to maneuver and swivel 360 degrees are attached to carts or equipment in many different ways. The most common is a flattop metal plate that anchors the caster to carts and equipment using bolts and nuts. Other forms of anchoring include the use of a threaded stem, a friction fit press-in stem into a socket, using an expandable adapter to fit into a round or square tube, or using a cylindrical stem with a cross-pin lock.

First and foremost, the way the caster is fastened to cart or equipment should be inspected to ensure the anchor bolts, thread stem or other types of fasteners have not become loose through application wear and tear. Examine how the caster is fastened to ensure nuts and bolts are firm and tight. If casters are stem types, make sure the legs of the equipment are not bent. Inspect for wear and tear on the socket holding the caster stem. As well, make sure casters with expanding adapter stems are held firmly in place in tubular equipment. Always use lock nuts or lock washers to mount casters to equipment.

In examining the swivel head mechanism, look for fallen or destroyed grease zerk nipples and replace where needed. The zerk enables grease lubricant to reach the inner raceway where bearing balls require the lubricant to facilitate ease of caster rotation and maneuvering. It is best to order casters with grease seals, which help to retain grease in the caster raceway and dirt out of the critical ball bearing pathway. Periodic lubrication of casters and wheels is essential to prevent equipment downtime. The lubrication schedule depends on the specific application. Normal conditions may warrant lubrication every six months; however, for wet or corrosive applications, monthly lubrication may be necessary.

Damage Control
The caster swivel assembly should be checked for excessive play due to wear. If the caster is made with a kingbolt and nut, make sure it is fastened securely and that it is not stretched due to impact forces the caster may be subjected to in daily operation. If the swivel does not turn freely, check for corrosion, a lack of grease or dirt binding the raceways. If the cart or equipment has rigid casters at one end, make sure the caster fork legs are not bent, distorted or misaligned due to side-thrust forces or impacts during use.

If the caster has been subjected to harsh operating conditions, visual wear and tear will be obvious in that the caster may be tilted, misaligned, excessively wobbly or prematurely bent due to overload conditions. Other functional impediments can be caused by weak weld or limited weld penetration at the time of caster fabrication. The caster frame may be too light duty for the application, which can cause dangerous collapse of cart or equipment. If the cart or equipment is traveling over rough terrain, excessive shock load or side thrust applied to the caster will cause it to deform if the casters are underspecified for use or application conditions.

If any of the above mentioned conditions are apparent, consult the manufacturer for caster specifications details and suitability of applied operating conditions.

Annoying Squeaks
A squeaky wheel is a sure indication the axle is dry of lubricant; the bearing has disintegrated; string strapping or other material has twisted around the axle impeding the wheel’s rolling ease; or that the fork legs of the caster are misaligned causing interference with the wheel’s movement. If the equipment or cart is subjected to wash down, essential lubrication may also be required after each wash down application. Special high-temperature, water-resistant lubricants must be used for these applications. In wet environments, consider using stainless-steel casters that require less maintenance and offer corrosion resistance in frequent cart washing applications.

Some new products in the market offer maintenance free casters. These casters are constructed using sealed precision bearings in either the wheel or swivel head mechanism, thereby eliminating the need to lubricate casters especially in wash-down applications.

Wheels should also be inspected for visible tread wear. For example, flat spots may indicate accumulation of floor debris, which can cause the wheel to bind. Alternatively, it may be due to excessive load beyond the capacity of the wheel to carry such a load. Inferior material and workmanship of low cost materials will also cause wheels to flat spot even at light loads. When it comes to casters and wheels, the lowest price is not always the best deal in town. Buyers beware! The addition of thread guards at time of purchase can also reduce build-up of string and thread wrapping between the wheel and axle. Maintenance should remove the wheel axle bolt and nut. Clean out the foreign material and check wheel bearings for wear and tear. Reassemble if parts are not damaged. After the wheels have been inspected and repaired or replaced, be sure the axle nut is properly tightened. Use lock nuts or lock washers on all axles.

Routine best practices in caster maintenance eliminate the costly down time typically associated with a lack of disciplined maintenance program. The use of casters should be an integral part of the cart or equipment design and fabrication, and not as an afterthought as to how to move the apparatus once designed and fabricated. To help you set up a maintenance program, consult the manufacturer of the casters that are now in use at your facility.

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Mike Titizian is the president of Colson Casters Ltd. in Cambridge, Ont. For more information, visit www.colson.ca or phone 1-800-643-5515.