TORQUE RODS

Torque Rods For Peterbilt Trucks

Torque rods — also called radius rods or torque arms — control axle position and resist the rotational forces of acceleration and braking on Peterbilt drive axle suspensions. They maintain proper pinion angle on the drive axles and prevent axle wind-up under hard acceleration or downhill braking. Worn torque rod bushings allow the axle to shift position, causing driveline vibration, driveshaft angle changes, and accelerated U-joint wear. We carry torque rods and torque rod bushing kits for Peterbilt trucks running common spring and air ride rear suspensions.

Frequently asked questions about torque rods

What are the symptoms of worn torque rod bushings on a Peterbilt?

Worn torque rod bushings typically produce a clunking or banging from the rear of the truck during acceleration and braking — the axle is shifting against the worn bushing instead of being held firmly. Driveline vibration that worsens under load, and driveshaft U-joints that wear out prematurely despite proper greasing, are also common signs of torque rod bushing wear allowing excessive axle movement. On air ride suspensions, worn torque rods can cause ride height instability as the axle shifts rearward under braking.

Can torque rod bushings be replaced without replacing the entire torque rod?

Yes — torque rod end bushings are replaceable separately in most applications, and bushing-only replacement is a cost-effective repair when the rod tube and end eyes are straight and undamaged. The old bushings are pressed out and new ones pressed in, which requires a press or suitable puller/installer tooling. However, if the torque rod has been operating with severely worn bushings for an extended period, the bore in the end eye may be worn oval, which prevents new bushings from seating correctly — in that case, complete rod replacement is the appropriate repair.

Do torque rods need to be replaced in pairs on a Peterbilt tandem axle?

On a tandem rear axle, each axle typically has its own torque rod arrangement — upper and lower rods on each axle. While it's not strictly required to replace rods in matched pairs the way shocks are, bushing wear tends to be similar across rods of the same age and mileage. If one bushing is severely worn, inspecting all rods in the suspension for similar wear is worthwhile, as replacing one worn rod while leaving adjacent worn rods in place results in the remaining rods taking disproportionate load and wearing faster.

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