Initial Inspection and Diagnostic Overview

Driveline System

Principals of Operation


Driveline System - General Information

The driveline system enables the power generated by the engine and transferred through the transmission in Front Wheel Drive (FWD), or the transmission and the Power Transfer Unit (PTU) in All-Wheel Drive (AWD) to place the vehicle in motion. Rotational torque received from the transmission or PTU is delivered to the front wheels by halfshafts or the rear axle by way of the driveshaft(s). The U-joints or CV joints at the ends of the shafts allow the shafts to rotate smoothly in an allowable angle plane. The rotational torque is introduced into the axle drive pinion which drives the differential ring gear. The ring gear is bolted to the axle differential which divides the torque between the left and right axle shafts, while permitting the shafts to turn at different speeds when required, such as when cornering.

Inspection and Verification

1. Verify the customer concern.

2. Visually inspect for obvious signs of mechanical damage.

Visual Inspection Chart







3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

4. If the cause is not visually evident, verify the symptom and GO to Symptom Chart - NVH. Symptom Chart - NVH


Driveshaft Center U-Joint and CV Joint Inspection

With the vehicle in NEUTRAL, position it on a hoist. Refer to Vehicle Jacking and Lifting. Rotate the driveshaft by hand. Check for rough operation or seizure of the U-joints or CV joints. Install a new driveshaft if it shows signs of seizure, excessive wear or incorrect seating. Refer to Drive/Propeller Shafts, Bearings and Joints.

Driveshaft Center Bearing

With the vehicle in NEUTRAL, position it on a hoist. Refer to Vehicle Jacking and Lifting. Rotate the driveshaft by hand. If the bearings show signs of roughness or are noisy, install a new driveshaft assembly. Refer to Drive/Propeller Shafts, Bearings and Joints.