Why should an impact wrench be avoided for installing drive axle shaft nuts?

Using an impact wrench for installing drive axle shaft nuts can lead to significant issues, particularly concerning hub bearing damage. An impact wrench operates by delivering high torque in quick bursts, which can easily apply excessive force to the nut. This sudden torque can stress the wheel hub bearings, potentially leading to premature wear or even failure of the bearings. Proper torque specification is crucial, as it ensures that the nuts are tightened evenly and securely, avoiding any deformation or misalignment of components.

In contrast, a manual or calibrated torque wrench allows for controlled application of force, enabling technicians to adhere precisely to manufacturer specifications. This careful approach mitigates the risk of over-tightening or uneven pressure, which is vital for maintaining the integrity of the hub bearings and ensuring the longevity and safety of the vehicle's drivetrain.