Proper maintenance is essential to keep trencher units operating efficiently. Performing routine maintenance and repairing minor problems as soon as they are identified reduce the chance of breakdowns in the field, and an effective maintenance program extends equipment life and protects the value of equipment.

Digging teeth, digging chain, and sprockets are the primary wear parts on chain-type trenchers. The process of digging a trench causes wear to these components—the more difficult the soil conditions, the more often they must be replaced. Operating a trencher with worn or damaged teeth, chain, and sprockets reduces digging efficiency and places extra stress on the machine, causing unnecessary wear and possible damage to other components.

Inspect digging teeth and chain daily or after each job.

When hard-faced surfaces of cup teeth are worn away, it is time to install new teeth. Replace teeth to conform to the tooth pattern on the digging chain. Insert bits are designed to rotate during trenching. If dirt or small pieces of rock lodge in the sockets (that hold each bit) preventing rotation, teeth will wear unevenly. Simply turning a bit usually removes dirt and debris. If a bit can’t be easily turned by hand, remove it and clean the inside of the socket. Also check for bit wear, and replace insert bits before they completely wear away. Continued use of worn bits eventually can damage bit holders on the chain, resulting in unnecessary expense.

A worn digging chain does not run smoothly and can generate shock loads which may damage other parts of the machine including the engine and transmission. Inspect digging chain, including roller links, for wear and correct tension. Operating equipment with worn chain links will cause sprocket teeth to completely wear through roller sleeves, damaging the pins that connect chain links.

Improperly tensioned chain reduces trencher performance, and the chain may slip off the sprockets. Putting a chain back on sprockets in the field is not an easy task. Refer to the operator’s manual for proper chain tension and procedures for making adjustments.

Worn teeth indicate it is also time to inspect sprockets, replacing them if necessary. When new sprockets are installed, it is best to replace the digging chain, also. Operating old, worn chain on new sprockets causes premature sprocket wear, and running new chain on worn sprockets causes excessive chain wear and could result in chain failure.

For most efficient production, chain and teeth should be correctly matched to digging conditions. Chain is rated by strength. Heavier-strength chains are recommended for difficult conditions. Cup teeth perform well in soft and medium soils and in sticky soils such as clay, but they are not recommended for rocky conditions. Carbide insert bits are best for digging through frozen ground and rock.

Because most jobs contain a mixture of soils, a short length of trench can contain several types of soil. A combination chain with both cup teeth and carbide bits often provides the best results in mixed-soil conditions.

Purchase replacement teeth, chain, sprockets, and other components that meet the specifications of your equipment. Inexpensive will-fit products may be less expensive to buy, but they often cannot withstand the severe stresses encountered during trenching. Service schedules and requirements vary with trencher make and model, so recommendations of manufacturers should be followed carefully. Refer to the operator’s manual for correct operating and maintenance procedures. Check engine oil and coolant levels on a regular basis, adding the correct fluids as necessary. Change fluids and filters at prescribed intervals, more frequently when operating in adverse or dusty conditions. Lubricate all service points, and maintain the hydraulic system at intervals prescribed by the manufacturer. Adjust chain or belt drives as necessary, and replace all guards and shields.

The Maintenance Payoff - The immediate benefits of equipment maintenance are dependable performance and less risk of a breakdown on the job. In addition, well-maintained equipment is safer to use and retains more of its value than neglected or indifferently serviced machines. Some equipment owners report their maintenance programs extend machine life by 20 percent or more.

Manufacturers do everything they can to make their equipment easier to maintain. Easy access to service points, use of components that do not require lubrication, and extended periods between service intervals are some of the strategies that help users take better care of their equipment.