Which part of a vehicle does Level 1 refurbishing focus on?

Level 1 refurbishing primarily concentrates on the replacement or significant repairs of the vehicle's chassis frame. The chassis serves as the base structure of the vehicle, providing support for various components such as the body, engine, and suspension system. By focusing on the chassis frame, this level of refurbishing ensures that the fundamental support structure of the vehicle is sound, which is crucial for safety and performance.

In this context, while engine upgrades, axle installations, and tire replacements may be important aspects of vehicle maintenance and improvement, they do not align with the core objective of Level 1 refurbishing. This is primarily about restoring or enhancing the structural integrity of the vehicle, which is most effectively achieved through chassis frame work.