The driver is doing the correcting
Every road has a crown, and every truck requires a small, constant steering input to hold a line. A correctly aligned truck requires a little. A misaligned one requires a lot, continuously, for the whole shift.
That is a driver fatigue issue before it is a tire issue, and it is one drivers rarely report because the effort builds gradually and gets attributed to a long day. A unit that comes back with a driver saying it was hard work is worth measuring even if nothing specific was complained about.
The tires report it too, just later: a steer worn on an edge, or feathered across the face so it feels smooth one way and sharp the other.
Loaded is the condition that matters
A truck that runs loaded one way and empty the other behaves differently in each direction, because weight changes how the suspension sits.
A unit with marginal geometry can be close to straight empty and out of line loaded, and the loaded half is where the work happens. Measuring on a rack rather than inferring from how it drives is the only way to settle that.
Both axles, then the trailer
A tractor alignment covers the steer and the drives. The drive axles decide what the front axle has to correct for, so aligning the steer alone produces work that undoes itself.
What gets measured is toe, camber and caster at the steer, drive axle alignment, and the relationship between them, which is what produces a truck running slightly crabbed. If the combination still tracks badly with the tractor right, the trailer is next: trailer alignment is offered here, and measuring both on one visit answers it properly.
What a correction is worth
Steer tire life, fuel, and the casing. A steer scrubbed away on one shoulder will not pass at the plant, so an alignment problem costs the tire and its retread value together.
Monroe also handles suspension work on light vehicles and runs seventeen services in total, which is more than either other Purcell location in Washington.
About this store
The Monroe store carries all nine Purcell tire categories and is managed by JR Webster. Lacey and Renton also align heavy trucks.
See the national heavy-duty truck alignment page for all 40 locations.