Vibration Conditions

Vibration, technically, is a high-frequency trembling, shaking or grounding condition, felt or heard, that is constant or variable in level and occurs during a portion of the total operating speed range. The types of vibrations that can be felt in the vehicle can be divided into three groups:

1. Vibrations of various unbalanced rotating parts of the vehicle.

2. Body and frame vibrations excited by powertrain, wind or road inputs. Aerostar is equipped with a flexible coupling and blade and block hangers which reduce exhaust system mount stressing.

3. Tip-in moans or resonance vibrations from stressed engine or exhaust system mounts or driveline flexing modes.

These vehicle vibrations can also be subdivided into those that occur at low speeds and those that are most noticeable at higher speeds. Since the dividing line between low and higher speed vibrations is not clear, there will be vibrations that overlap the two ranges.

Typical Low Speed Vibrations (Less Than 72 km/h [45 mph])
- Exhaust vibration.
- Engine harshness.
- Driveline vibration due to improper driveline angles.
- Power steering pump disturbances.
- Air conditioner compressor or drive belt vibrations.
- Takeoff shudder (clutch or driveline problems).
- Brake roughness or harshness.
- Driveline roughness.
- Clutch torsion vibration.
- Driveline slip-yoke or U-joints, automatic transmission clutch slippage.

Typical High-Speed Vibrations (Above 72 km/h [45 mph])
- Axle and companion flange runout or imbalance.
- Driveshaft imbalance.
- Excessive tire-wheel and drum assembly imbalance.
- Tire roughness due to high non-uniformity (force variation) or out-of-balance condition.
- Rear axle pinion gear pitch line runout.
- Excessive tire and wheel runout.
- Worn suspension components.
- Front end accessory vibrations.
- Exhaust vibration. Exhaust vibration is greatly reduced in some exhaust systems de-coupled by a flexible coupling and mounted with blade and block hangers.