Torsion Bar

Torsion bars are longitudinal spring elements utilizing torsional resistance to provide suspension support, commonly found in independent front suspensions of trucks and some rear suspensions. These heat-treated alloy steel bars are anchored at both ends of the vehicle chassis and twisted by suspension movement, offering a variable spring rate proportional to the degree of twist. Adjustment is typically achieved via eccentric locknuts modifying preload. Unlike coil springs, torsion bars offer increased ground clearance and design packaging flexibility. Failure modes include cracking due to fatigue or corrosion, often presenting as noticeable ride degradation or suspension component misalignment.