What should be used in transmission installation to prevent damage to the main drive bearing?

Using pilot or guide pins during transmission installation is essential to accurately align the transmission with the engine and prevent damage to the main drive bearing. These pins help guide the transmission into place, ensuring that splines and other components mesh properly without applying undue stress or misalignment. If the transmission is not aligned correctly, it can lead to severe wear or even damage to the main drive bearing and related components.

Proper alignment is crucial because misalignment can cause binding, excessive friction, or even destruction of the bearing over time. By incorporating pilot or guide pins, technicians can ensure a smooth, precise fit that minimizes the risk of these issues during installation.

Other methods, such as using a torque wrench, impact gun, or simply relying on transmission fluid, do not address the alignment issue directly and could lead to improper installation or damage.