Why is pre-load needed in rear axle adjustment?

Pre-load in rear axle adjustment is essential to ensure proper bearing tension and alignment, which minimizes play and enhances stability during operation. It helps to prevent premature wear of components by maintaining consistent contact between gears and bearings, ultimately leading to improved performance and longevity of the axle assembly. Proper pre-load also aids in managing heat generation, reducing the risk of overheating and potential failure during high-stress conditions.