DRIVE SHAFTS

Drive Shafts For Peterbilt Trucks

The driveshaft transmits engine torque from the transmission output to the drive axles on a Peterbilt truck. On tandem rear axle configurations common to Class 8 Peterbilts, there are typically multiple driveshaft segments — a main shaft from the transmission to the forward rear axle, and an inter-axle shaft connecting the forward and rear tandems. Worn U-joints, out-of-balance shafts, and damaged slip yokes cause vibration, drivetrain noise, and in severe cases, catastrophic driveshaft failure.

Frequently asked questions about drive shafts

What causes driveshaft vibration on a Peterbilt?

Driveshaft vibration is most commonly caused by worn or failed U-joints, an out-of-balance shaft from a bent tube or missing balance weight, or improper phasing after a shaft has been removed and reinstalled incorrectly. Vibration that appears at a specific road speed and stays consistent points to a balance issue, while vibration that changes with load or varies under acceleration vs. deceleration more often indicates a worn U-joint or slip yoke.

How do I check U-joints on a Peterbilt driveshaft?

With the driveshaft stationary, grip the shaft firmly and attempt to rotate it while holding the yoke — any rotational play indicates a worn U-joint. Also check for axial movement (in-and-out) in the bearing cups, and inspect for rust migration and grease loss around the caps. U-joints with a grease fitting should be lubricated at every PM interval; dry U-joints wear rapidly and can fail without warning.

Can a driveshaft be repaired, or does it need to be replaced?

U-joints are serviceable and can be replaced without replacing the entire shaft if the tube and yokes are in good condition. Bent or cracked driveshaft tubes require shaft replacement or professional rebuilding with a new tube section. A driveshaft shop can also re-balance, re-phase, and inspect slip yoke wear — rebuilding is often more economical than replacement for large-diameter heavy-duty shafts.

Other parts you might need

Shop transmission parts for Peterbilt trucks