What should be done to the inside surface of new blocker rings during installation?

When installing new blocker rings, the inside surface can benefit from both polishing and light sanding. Polishing with crocus cloth helps to create a smooth finish that reduces friction and wear. This process helps ensure that the blocker rings engage more smoothly with the synchronizer hubs, leading to better performance and longevity.

Lightly sanding with #400 grit paper can also be advantageous, as it helps to remove any imperfections or debris from the surface that could impede performance. The combination of these methods allows for optimal surface preparation, ensuring that the blocker rings can effectively perform their function in synchronization, which is especially important in manual transmissions that rely on smooth gear shifts.

By performing both polishing and sanding, technicians can improve the contact surface qualities, thereby enhancing the overall effectiveness of the transmission system. This careful preparation supports the transmission's function and longevity, making the installation of the blocker rings reliable.