Kenworth’s KWC suspension is a dual rear axel suspension with two, 127 mm (15 in.) wide gull wing beams under slung on the axel housings.

A cast eye is bolted to the beam ends and the beam is anchored at each and by a hardened steel pin.

The suspension has a ground load capacity of 13 710 to 54 360 kg (70,000 to 120,000 lbs.).


1.    Lubricate torque rod bushings every 10 000 km (6,000 miles) with chassis lub

2.    Maintain nuts at proper torque. (first picture)

3.    Examine the wear plate. Replace if holes appear.

4.    Examine the steel pin anchoring the beam.

5.    Examine the rubber bushing located in the center of the beam. Replace the bushing if there is shearing around the edge of the rubber.

Axel alignment:

Alignment should be checked after replacing an axle or suspension system components.

Also check the alignment if excessive tire wear occurs which is not caused by tire operation.

1.    Drive the truck backward and forward in a straight line to allow the axles to ressume their neutral position.

2.    Clamp a straightedge across the frame of the truck. The straightedge must be square to the frame and project at least 0.6 meters (2 feet) beyond the frame rail on each side.

3.    Using a plumb bob, transfer the location of the straightedge and the center of forward rear axles to marks made on the floor.

4.    With a trammel bar, measure the distance from the straightedge to the center of the forward rear axles and from the center of the forward rear axles to the center of the rear-rear axles.

5.    Corresponding measurements from both sides of the truck ( A1 and A2/B1 and B2) should not vary more than 1.59 mm ( 1”/16 in.).


6.    To adjust axles alignment add or subtract the 16mm (5/8 in.) heat treated washers ( spacers) on the torque rod mounting bolts and rotate exocentric bushing where the cast eye is bolted to the beam.