Durability is one of trailer spring suspensions’ claims to fame, with spring suspensions often outlasting the life of the trailer. That’s not to say it’s a “spec it and forget it” component. On the contrary, according to Collin Parker, engineering project manager for Hutchens Industries, the number one reason for premature spring suspension failures is lack of maintenance.
Spring suspension manufacturers’ maintenance recommendations include periodic checks of fastener torque values and usually include an initial re-torque after break-in. While regular preventative maintenance will keep the majority of spring suspensions rolling productively, there may come a time when a spring needs to be replaced. Typically, a broken spring can be identified during a walk-around inspection, but Parker pointed to the CVSA out-of-service requirements for a spring assembly to identify an issue. These require replacement if:
- One-fourth or more of the leaves in any spring assembly are broken;
- Any leaf or portion of any leaf in any spring assembly is missing or separated; and/or
- There is any broken main leaf in a leaf spring.
“If a spring breaks during operation, there may be a myriad of indicators depending on which spring leaf has broken,” Parker said. “A break in a supporting spring leaf in the spring assembly may or may not create some minor sagging of the trailer on the affected side. A main leaf break would be more noticeable and be more likely to result in trailer lean and reduced tire clearance.”
Parker recommended that the trailer be unloaded during spring replacement and noted that while it is possible to perform a spring replacement with a loaded trailer, the jack or lift and stands would need to have a much higher capacity rating. If there is ever a question regarding capacity, err on the side of caution and unload the trailer.
“Any reputable service center will have an emphasis on safety,” Parker said. “A mechanic should always follow OSHA requirements as well as any employer and employee requirements. This should include personal protection equipment, lock-out tags where applicable, and never working under a trailer only supported by a jack.”
Spring replacement is well within the capabilities of reputable trailer repair shops and within the scope of in-house work, as long as you have the right tools and training for your shop’s technicians.
“Any time a suspension component is to be replaced, the remaining suspension components should be examined as well,” Parker said. “If any other components have been compromised, they should be replaced. We also recommend new fasteners when replacing components. This is especially true when talking about u-bolts.”
In terms of downtime, the actual spring replacement takes approximately two hours and should include alignment.
Of course, a broken spring on the side of the road can put your trailer out of service longer. You can’t predict the figure, but you can mitigate your risk by staying up on your daily inspections and regular preventative maintenance.