Preventative maintenance is essential for any work vehicle or piece of equipment—but for digger derricks, the stakes are even higher. Any time equipment is hoisting personnel or operating near energized lines, it requires a more rigorous maintenance schedule to keep crews safe and jobs on track.
We spoke with industry experts from Altec and Terex Utilities to break down the must-do preventative maintenance steps for keeping your digger derrick in top working condition.
Tip #1 – Know Your Standards and Follow Them
Regulatory standards form the backbone of any preventative maintenance program. OSHA 1926.1412 lays out the required frequent and periodic inspections, and ANSI/ASSP A10.31 provides additional guidance. Pair these with your manufacturer’s maintenance recommendations to make sure your PM plan is both safe and compliant.
Why it matters: A well-structured PM schedule ensures safety systems work when you need them and helps extend machine life.
Tip #2 – Perform a Complete Daily Walkaround 
Before every shift, inspect for malfunctions, wear, leaks, or damage. According to OSHA 1926.1412, your daily checklist should include:
- Control and drive mechanisms
- Hydraulic and pressurized lines, plus fluid levels
- Hooks, latches, and wire rope reeving
- Electrical apparatus and safety devices
- Operator cab windows and warning labels
- Winch rope condition and OSHA 1926.1413(a) compliance
If you find any issues, a qualified person—such as a trained operator, service tech, or manufacturer support—should determine if it’s safe to continue.
Tip #3 – Inspect and Care for the Winch Rope
Winch ropes are one of the most commonly replaced items on a digger derrick.
- Know your rope’s working load limit.
- Use lifting chains or straps when handling poles with synthetic ropes.
- Understand when two-parting is needed and follow the correct procedure.
Pro tip: Regular rope checks can prevent sudden failure during a lift.
Tip #4 – Test All Safety Systems
During your pre-operation checks, confirm that:
- Joysticks return to neutral and stop functions immediately
- Emergency stops work as intended
- All interlock systems are fully operational
Small malfunctions here can lead to major safety risks.
Tip #5 – Stick to 90-Day, 180-Day, and Annual Intervals
Manufacturer maintenance schedules are your roadmap for preventative care. For example, Terex outlines:
90 Days: Replace return filter, torque-check auger fasteners, lubricate grease points.
180 Days: Torque-check rotation bearing bolts, inspect hoses, clean hydraulic tank breather.
Annual: Inspect and lubricate PTO pump splines, test hydraulic oil, perform cylinder drift test, inspect structural welds, check pressure settings, lubricate extension cables.
For insulating units, include an annual dielectric test.
Tip #6 – Keep Up with Monthly and Annual OSHA Inspections
Monthly: Inspect the same points as daily checks, document results, and keep records for at least three months.
Annual: Have a qualified inspector examine structural components, safety devices, brakes, hydraulic systems, electrical wiring, tires, outrigger pads, and more—often requiring some disassembly.
Tip #7 – Maintain the Chassis Like Any Heavy-Duty Truck
Follow your chassis OEM’s service intervals and DOT inspections. Even though the digger derrick’s unique components require extra care, the truck itself still needs routine heavy-duty diesel maintenance.
Tip #8 – Track Performance and Usage
Use inspections and PM intervals as a time to review maintenance records and spot patterns. Repeated issues might mean you need to adjust your schedule or change operating practices.
Tip #9 – Leverage Telematics for Early Problem Detection
Systems like Altec Insights and Terex Fleet Horizon provide fault codes, usage tracking, and remote troubleshooting. These can:
- Catch hidden issues before they cause downtime
- Track PTO hours and boom usage to identify heavily used units
- Help prioritize more rigorous PM schedules for high-use equipment
Tip #10 – Never Ignore Minor Issues
Any unsafe condition must be corrected before operating the digger derrick again. Only qualified personnel should perform adjustments or repairs. Manufacturer support teams, like Altec Support (1-877-GO-ALTEC) and Terex (1-844-TEREX-4U), can help troubleshoot and recommend solutions.
The Bottom Line
Preventative maintenance isn’t just about compliance—it’s about protecting your crew, your equipment, and your bottom line. By sticking to a consistent inspection schedule, caring for key components like the winch rope, and using tools like telematics to stay ahead of problems, you’ll keep your digger derrick operating safely and efficiently for years to come.
See It in Action
Want to take your digger derrick knowledge even further? Join us at The Utility Expo October 7-9, 2025 in Louisville, Kentucky to get hands-on with the latest equipment, tools, and technology in the industry.
From live demonstrations to expert-led sessions, it’s your chance to see best practices in action, connect with leading manufacturers such as Altec and Terex, and bring back new ideas to keep your crews safe and your fleet running at its best.
See the full list of companies that will be exhibiting at The Utility Expo 2025: Exhibitor Directory.
Subscribe to The Utility Expo monthly newsletter to receive more industry insights like this.
Read Next
What’s New in Digger Derricks: Capacity, Speed, Flexibility, Safety
Tips for Choosing the Right Digger Derrick Auger Tool for the Job
Top Trencher Advancements Every Utility Contractor Should Know
Top Aerial Lift Innovations Improving Utility Safety and Productivity
