Determining gearbox faults by noise (Chevrolet Niva 1)

Troubleshoot in the following order.

Test 1. To clearly identify the nature of the noise, drive the car on the highway at a speed of approximately 20 km/h. Then gradually increase the speed to 90 km/h, listening simultaneously to different types of noise and noting the speed at which they appear and disappear.

Release the throttle pedal and reduce engine speed without braking.

When slowing down, pay attention to the change in noise, as well as the moment when the noise increases. Usually, the noise appears and disappears at the same speeds both during acceleration and deceleration.

Test 2: Accelerate the car to approximately 100 km/h, put the gearshift lever in neutral and let the car roll freely until it stops; observe the nature of the noise at different deceleration rates.

The noise, which depends on the manipulation of the accelerator pedal, comes from the main pair.

Bearings can also make noise when coasting: the bearings of the drive gear make noise with a "hissing" and "rumbling", and the bearings of the differential and axle shafts produce a low-frequency "rumbling".

Test 3. With the vehicle stationary and braked, turn on the engine and, gradually increasing its speed, compare the noises that arise with those noted in the previous tests. Noises that are similar to those of test 1 indicate that they are not gearbox noise and are caused by other components.