Analysis of Vibration

DESCRIPTION
Few vibration conditions are caused by the rear axle. Most vibration in the rear end is caused by tires or driveline angle.

TIRES

WARNING: Do not balance the rear wheels and tires while they are mounted on the vehicle. Possible tire disintegration and/or differential failure can result, causing personal injury and/or extensive component damage. Use off-vehicle wheel and tire balancer only.

Vibration is a definite concern with modern, high-mileage tires if they are not "true" both radially and laterally. They are more susceptible to vibration around the limits of radial and lateral runout of the tire and wheel assembly. They also require more accurate balancing. Wheel and tire runout checks, truing and balancing are normally done before axle inspection.

DRIVELINE ANGLE
Driveline angularity is the angular relationship between the engine crankshaft, the driveshaft and the rear axle pinion. Factors determining driveline angularity include ride height, rear spring, and engine mounts.