Sliding tandems are adjusted every day, and checked almost never
Many trailers carry a sliding tandem: an axle assembly that moves along the frame to balance the load between the trailer axles and the tractor. Drivers slide it routinely, sometimes several times a week, and each time the assembly is unlocked, moved and locked again.
Every one of those moves is a chance for wear to build up in the slider rails, the locking pins and the mounting. Over time, an assembly that has been slid hundreds of times can sit slightly out of square with the trailer even when it is locked correctly. The axles then roll at a small angle to the direction of travel, and the tires scrub.
Nobody connects that to the slider. The trailer looks fine, the pins are in, and the wear on the tires is put down to the tires.
Check the slider as part of the trailer
When a trailer with a sliding tandem comes in for alignment, have the slider assembly looked at too: the rails, the pins and the mounting hardware. An alignment set on worn hardware will not hold, and the next slide puts it back where it started.
For a fleet, trailers whose tandems are slid most often are the ones to check first.
Signs worth acting on
- Tire wear on the trailer that is heavier on one side.
- A tractor that pulls when hooked to one particular trailer.
- Pins that are difficult to engage or that have visible wear.
Do the tractor too
A tractor and trailer out of line with each other wear both. Heavy-duty truck alignment is offered here, and a fleet can set up regular checks through a fleet account. The national trailer alignment page covers what the measurement includes.
Other stores nearby
The Salt Lake City commercial and consumer store and Ogden also align trailers.
About this store
This is the Truck Tire Center listing, open Monday to Friday, 8:00 AM to 5:00 PM. Distribution Services shares its address and handles tire supply only. See the Salt Lake City page for all four listings.
See the national trailer alignment page for all 36 locations.