Measure a sample rather than the whole fleet
An operation with more trailers than tractors cannot measure everything at once, and does not need to.
Measure a handful and you learn something about all of them, because what you are looking for first is not which individual trailer is crooked. It is whether you have a fleet-wide problem or a few bad units, and those call for completely different responses.
A few trailers out, the rest fine. Those units have histories: a collision repair, a dock strike, a hard load. Deal with them individually and the problem is solved.
Most of the sample out, in a similar way. That is not bad luck. Something systematic is doing it, which usually means how they are loaded, how they are handled in a yard, or a specification that does not suit the work. Measuring every trailer will confirm what the sample already told you, at considerably more cost.
Pick the sample sensibly: a couple you suspect, a couple you have no reason to suspect, and one of the oldest.
What gets measured
Axle alignment to the kingpin, the relationship between axles on a tandem or tri-axle, and the condition of the suspension and mounting hardware.
Heavy-duty truck alignment is at the same store, so a combination can be measured rather than one end of it.
What the tires tell you first
The national trailer alignment page covers the signs. In a fleet, the tire records usually identify the sample for you: whichever unit numbers keep appearing against replaced trailer tires are the ones to put on the list.
About this store
The Mabelvale store carries trailer tires and every other Purcell category, and is managed by Corey Germany.
See the national trailer alignment page for all 36 locations.