Dock work is where trailers get hurt
A trailer that spends its life backing into docks, maneuvering in tight yards and being dropped on uneven ground accumulates damage that a highway trailer does not.
Dock strikes, landing gear dropped onto broken pavement, trailers parked for weeks on a slope with the weight all in one place: none of it is reported, because none of it stops the trailer working. The frame and the axles take it, and the tires start paying.
A drop yard full of trailers is also a place where nobody is assigned to notice. Tractors have drivers who complain. A trailer has whoever picks it up next.
The evidence is on the tires
The national trailer alignment page lists the signs. In a drop yard the practical problem is that no single person sees enough of one trailer to notice any of them, since whoever hooks up next is a different driver each time.
Which makes the tire records the only continuous observer you have. Whichever unit number keeps appearing against replaced trailer tires is the one to measure.
A trailer carries most of the weight in a combination and has more tires on the ground than the tractor, so it loses more rubber per mile to the same fault than the tractor would.
What gets measured
Axle alignment to the kingpin, axle-to-axle relationship on a tandem or tri-axle, and the suspension and mounting hardware holding everything in place.
Renton also aligns tractors. Measuring the combination rather than one end of it is what settles which is at fault, and for a fleet with stable pairings it establishes a baseline to compare against later.
Picking which trailers to measure
A fleet with more trailers than tractors cannot do all of them at once, and does not need to. Start with the ones whose tires keep coming off early, and the ones you know have taken a hit.
If the same position wears across the whole fleet, that is a different finding: loading, specification or operating practice rather than one bad trailer.
About this store
The Renton store carries trailer tires and every other Purcell category, and is managed by Chris Contrades. Lacey and Monroe also align trailers.
See the national trailer alignment page for all 36 locations.