Technical Bulletins


  • Tractor
  • Truck - Medium
  • Truck - Heavy
  • Trailer
  • Bus & Coach
  • Fire & Emergency
  • Construction
  • Military
  • Motor Home

Did You Know?

WABCO is the first to the NA market with OnGuard. 90,000+ systems in the field and 32 billion highway miles.

Tag Axle Control System

WABCO is focused on continuously developing integrated safety technology and efficient system solutions, delivered by the broadest and most experienced support network.


WABCOs Tag Axle System includes a semi-automatic intelligent ECU that is designed to improve tire wear and trailer maneuverability. The SmartTrac Tag Axle System helps to reduce wear associated with tire scrubbing by reducing the load on the tag axle during parking lot maneuvers and cornering. This system works with WABCO RSS (Roll Stability Support) and WABCO InfoLink capable ABS products. Fleets that want to mitigate expenses associated with tires such as premature tire wear and replacements would benefit from this system.

Once the driver activates the Tag Axle Control System the spring bag pressures are lowered. In order to reduce the chances of overloading the tag axle, WABCOs Tag Axle Control System continuously detects when vehicle speed has exceeded 10 mph for a minimum of 30 seconds and automatically inflates the spring bag to normal pressures. It controls the air spring pressures by monitoring wheel speed and detecting switch activity from the tractor cab. This feature is beneficial in situations when drivers forget to inflate spring bags at high speeds, which leads to overloaded axles.

Frictional forces generated during cornering and braking can be much more damaging to tires than driving straight. Additionally, curved turns lead to lateral tire deformation and uneven tire wear which increases fleet costs. WABCO’s Tag Axle Control System helps to alleviate costs by reducing stress on tires.

Features & Benefits

  • Increased vehicle maneuverability
  • Reduced tire scuffing
  • Reduced stress on wheels and chassis components
  • Reduced tire costs
  • Reduced labor and maintenance cost
  • Semi-Automatic
WARNING: This product can expose you to chemicals including Nickel, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to