The Chain Gang
Preventative and Daily Maintenance for Trencher Chain Upkeep
By Dan Roberts

Routine maintenance on the chain of a dedicated trencher or a trencher attachment can spell the difference between being productive and profitable and having an unexpected breakdown. Because trenchers have many ground-engaging parts, it’s typical for some components to wear with use over time. One of the most commonly affected parts is the trencher chain. Although the trencher chain inevitably wears with time, the following routine maintenance tips can you help extend its life.

Retain proper chain tension: This is one of the most important maintenance procedures you can perform on your trencher. When a chain is tensioned too loosely or too tightly, the trencher will not perform to its full potential, prematurely wearing parts due to unnecessary stress. This stress can cause wear on the inside of the chain, trencher boom, roller and drive sprocket.

Chain tension refers to the chain sag from the bottom of the trencher boom to the top of the chain. This sag needs be maintained at 2 to 3 in. When working in wet soil types that collect on the chain, the adjustment should be at 3 in.
Remember to clean the chain prior to making any adjustment. Chain adjustment is made by moving the boom by turning a threaded screw and lock nut. As a general rule, if the threaded screw is on the backside of the boom, turn counterclockwise to decrease chain sag. If the threaded bolt is in the boom, clockwise rotation will decrease the chain sag.

Check chain wear: Chains wear at each pivot point at each link. To properly check chain wear, the chain needs to be removed from the trencher and boom and laid out straight on a hard, level surface. Wear should not exceed 3 percent from when the chain is fully collapsed to fully extended.

To calculate wear, lay out the chain and then push it together on each end so the chain is at its shortest length. Use a tape measure to measure the length of the chain from end to end, marking the points at which the chain is measured. Pull on each end of the chain until it is extended to its fullest length and measure at the same marked points. The chain should be replaced if there is more than a 3 percent difference between its collapsed length and fully extended length.

Examine tooth condition: Many styles of trencher teeth include carbide inserts on their sides, tops or faces.

When this carbide is worn flat or worn away, the tooth needs to be replaced. Teeth may look similar, but they can vary by height and the cup depth. Mismatched teeth can put additional load on a trencher and can shorten the life of a hydraulic system.

Grease all moving parts: Routine greasing of all the moving parts with a grease gun will improve the performance and life of the trencher. Chains, however, do not need lubrication on a regular basis. If a chain is being placed into long-term storage, it needs to be cleaned, and the chain pivot points should be lubricated with a spray lubricant.

Perform daily maintenance: Inspect, clean and grease the trencher daily at the beginning or end of the day. Dried mud and debris lodged in trencher parts, particularly the trencher chain, can cause increased wear on the mechanism, so it’s important to keep the trencher clean. Cleaning can be accomplished by pressure washing with water.

Consult your local dealer if you are uncertain about performing any maintenance or repair procedure on your own. To attain optimum performance and the longest life from a trencher, your best bet is to use the manufacturer’s specified OEM parts.
Operating a trencher without taking the time for proper set-up and upkeep can result in expensive, long-term consequences. By following a few simple procedures with each use, you can significantly reduce repair and downtime, allowing your trencher to work for you over the long haul.

Dan Roberts is a technical service representative with The Toro Co., Bloomington, Minn.