1.1.5.2.3.1 Non axle noise The five most common non axle noises are exhaust, tires, roof frame, trim panel and transmission. Therefore, before performing drive train disassembly and diagnosis, make sure that the following conditions are not the cause of the noise: In some cases, the exhaust sounds very much like gear noise.Some may be mistaken for the rumble of wheel bearings. Tires, especially snow tires, emit a high pitched rumble similar to gear noise.Radiation tires also have this characteristic.At the same time, any non-standard tire with a unique tread pattern may also produce a rumbling sound. Trim panels can also whistle or whine.
When the automatic transmission is engaged, there may be metal knocking.This is due to a backlash somewhere in the drive train. The rumble of the bearings sounds like marble rolling.This is usually due to damage to the wheel bearings. 1.1.5.2.3.2 Noise condition Gear noise is usually caused by gear damage or improper bearing preload, resulting in growl or whine.It may occur at different speeds and driving conditions, or it may continue. A typical cluck sounds like a stick inserted into a spinning bicycle wheel.It occurs when the vehicle decelerates from 64km / h and usually lasts until the vehicle stops.The frequency varies with the speed of the vehicle.
Knock sounds like a clucking sound. It occurs and becomes loud when accelerating or decelerating.The location of repair can be found by removing some parts. 1.1.5.2.3.3 Clucking, knocking or rubbing may be caused by the following reasons Wear, damage or incorrect installation of wheel bearings, suspension or brake components. Before disassembling the transmission to perform diagnosis and repair of gear noise, check and eliminate tire, exhaust and trim panel items. 1.1.5.2.3.4 Vibration condition The vibration on the road may be caused by the following reasons: Front or rear wheel imbalance. The tire is out of round.
Vibration or vibration during acceleration may be caused by the following reasons: Powertrain / drive system mount damaged. Excessive operating angle of constant velocity (CV) joint due to incorrect body height.Check the body height, confirm the correct spring rate, and check the items that cannot be operated. 1.1.5.2.3.5 Road test The parts driven by the gears produce a certain amount of sound.Some noises are acceptable and may only be heard at certain speeds or under different driving conditions. For example, on a newly paved asphalt road, some noises must be regarded as normal.
Road testing and customer interviews, if possible, can provide the information needed to confirm the situation and provide direction for the correct starting point of diagnosis. (1) Record the whole diagnosis process.Even the smallest information must be recorded, because it may become the most important.
(2) Do not touch any parts until the road test and a thorough visual inspection of the vehicle have been completed.Maintain the tire pressure and vehicle load as they were when the condition was first detected.Adjusting tire pressure, vehicle load, or other adjustments may reduce the strength of the condition to a level that cannot be clearly identified.It may also cause something to get into the system and hinder proper diagnosis. 26