Steering and suspension components are safety critical parts on vehicles that have to deal with a huge variety of road conditions. Making sure a component is up to the job means that aftermarket parts must undergo rigorous testing. As a leading aftermarket supplier in this field, Delphi takes product testing seriously.

Delphi has just completed a new round of quality tests for its suspension ball joints, wishbones, tie rod ends, inner tie rods and link stabilizers. To replicate differing conditions and wear patterns, the test varied from simple push/pull testing on the complete assembly, testing for fatigue and bearing wear due to impact through reciprocal loading, to more precise dimensional analysis, ensuring geometric compatibility between the OE and aftermarket product. There was also stringent analysis of the chemical composition and mechanical properties of the materials used in the component composition.

Ball joints in particular have been identified by Delphi as safety critical components that have very serious consequences should they fail. In some tests, the force required to push out or remove the ball-pin from the housing is measured. Delphi ball joints are tested on a three-axis test rig and environmental chambers set at -40°C to see what effect extreme temperatures have on the components.

Additionally, ball-pin rotational and breakaway torque testing, measured the force required to rotate the ball-pin within the housing, essential for smooth steering movement. The breakaway test measured the force required to move the ball-pin when the steering wheel turns. With higher torque values than the OE, steering could be stiff and difficult to self-centre after turning. If less than the OE, the steering could feel loose and unstable. Delphi perfectly matched the OE part in both torque tests.

Delphi wishbones, inner tie rods and tie rod ends are also subjected to the same push/ pull testing, as well as durability testing on the three axis rig and environmental chamber. Ball pins are also 100% crack tested; castings undergo ultrasonic crack detection to ensure material is flaw free.

In addition, Delphi link stabilizers undergo the same testing as the ball joints, plus tensile strength testing to validate the product housing and welding strength. As a result of this latest round of testing, Delphi can show that their parts fully meet the OE specification in terms of dimensions and performance.

Qualvecom distributes Delphi Steering and suspension parts in Ireland and they are available from motor factors nationwide. For more information visit www.qualvecom.com.