Why Trailer Maintenance Matters as Much as Tractor Maintenance

Ensure safety, compliance and uptime with your trailers

A mobile maintenance technician works on a white refrigerated trailer.

Fleet maintenance often focuses on the tractor, but trailers deserve equal attention. They don’t have engines or complex drivetrains, which can make them seem less demanding, but trailers are still subject to constant wear and tear. More importantly, key trailer components play a direct role in road safety, regulatory compliance and uptime.


“Regular maintenance keeps trailers reliable and safe, helps avoid expensive breakdowns, and improves fuel efficiency. It also ensures trailers meet Department of Transportation (DOT) regulations,” said Chris Hough, vice president of maintenance design and engineering for Penske Truck Leasing.

Understanding Cost, Safety and Uptime Implications

Maintenance practices directly affect safety outcomes and financial performance. Delaying or skipping maintenance can result in premature part failure, tire issues, such as blowouts and accelerated tread wear, wheel bearing issues and wheel seal failures. Issues can also extend into brake failure from worn or improperly adjusted linings and suspension problems, such as worn bushings, broken leaf springs or leaking airbags that lead to unstable conditions.

“Vehicles out-of-service at DOT checks result in downtime, fines and costly roadside repairs,” Hough said.

The Federal Motor Carrier Safety Administration’s Compliance, Safety, Accountability program doesn’t distinguish between tractor and trailer violations, and they all count toward a fleet’s safety score. Common trailer-related violations include brake system issues, inoperative lights and tire defects.

“The most common trailer maintenance mistakes I see are fleets neglecting wheel bearing maintenance on semi-fluid hubs, overlooking tire pressure and irregular tread wear, conducting incomplete brake inspections and ignoring electrical wiring corrosion issues,” Hough said.

Trailer tires and tire inflation systems also often get overlooked. “When not maintained, both will lead to unscheduled downtime and increase tire expenses,” Hough said.

Making Time for Maintenance

A solid maintenance program helps mitigate accidents, ensure compliance, improve fuel economy and extends equipment’s lifespan while also reducing unexpected failures and costly unscheduled roadside repairs.

Technology is enabling the industry to transition proactively and drive a data-driven approach to address issues. “Smart component monitoring, real-time telematics and automatic tire inflation systems are becoming more common in our industry, enabling planned instead of reactive maintenance,” Hough said.

In addition to regular preventive maintenance, daily pre- and post-trip inspections remain a key part of effective maintenance programs, particularly for high-wear components. “Tires and lighting are subject to abuse and should be inspected daily to ensure they are road-ready,” Hough said, adding that brake components should also be closely checked during the inspections. “A federal annual inspection is also required.”

Hough advised fleets to leverage technology and data, perform planned proactive preventive maintenance on schedule, develop a solid pre- and post-trip program, and follow through on defects identified during inspections.

Maintaining Trailers and Capacity

All of Penske Truck Leasing’s dry van, flatbed and refrigerated leased trailers include preventive maintenance and 24/7 roadside assistance. Penske Truck Leasing also offers contract and on-site mobile maintenance.

If unexpected issues arise with a trailer, flexibility becomes key. Penske offers rental trailers and short-term equipment solutions to help fleets maintain service levels during repairs and inspections or reduce pressure on in-house maintenance schedules.