What should a technician do first when replacing a leaky drive pinion seal?

When replacing a leaky drive pinion seal, the technician should first check the yoke surface. This is crucial because a worn, damaged, or rough surface on the yoke where the seal makes contact can lead to premature failure of the new seal. Ensuring the contact area is smooth and free from any debris will help create a proper seal and prevent future leaks.

The correct process involves inspecting and potentially repairing or replacing components before installation. After confirming that the yoke surface is in good condition, the technician can then proceed to install new components such as spacers or shims if needed to maintain the correct pinion depth and gear alignment. Neglecting this step may lead to misalignment, which could result in additional issues, including vibration and noise from the differential.

Therefore, addressing the condition of the yoke surface is a vital first step in the process of replacing a drive pinion seal, thus preventing future problems and ensuring a successful repair.