A drag link is a part of the steering gear in a vehicle. Its function is to convert the rotary motion of the steering box or crank to a secondary link or crank. The drag link operates to adapt the sweeping arc of the steering box to the linear motion that is required to pull the tie rods which will ultimately turn the vehicle's wheels.
In a typical drag link, one end of it is connected via the Pitman arm, a linkage attached to the steering box, to the vehicle’s steering wheel. It is the part of the steering gear that translates the driver’s use of the steering wheel to the reaction of the vehicle’s wheels. As such, it is an essential component of the operation of the vehicle’s steering system.
Drag links can wear after time particular if the vehicle has suffered heavy use. The consequences of a worn drag link can drastically affect the performance of the vehicle. The car may feel as if it is “wandering” or give the impression that one of the tyres is low on air. The greater the drag link wear, the more difficult the steering, handling and stability issues are likely to be.