The grease fitting in a steering linkage is also called​ a(n) ________ fitting.

The correct answer is that the grease fitting in a steering linkage is commonly referred to as a zerk fitting. Zerk fittings are specialized components designed to allow for the easy addition of grease to lubricate parts within a steering and suspension system, ensuring smooth operation and reducing wear over time. These fittings are used in various automotive applications, including ball joints, tie rod ends, and steering components.

Zerk fittings typically feature a small, cylindrical design with a ball check valve that prevents the grease from escaping after being injected, which helps maintain the lubrication within the component. Proper lubrication is essential in steering and suspension systems to prevent friction and excessive wear that could lead to component failure.

In contrast, the other terms like pitman, adaptive, and compression do not accurately describe grease fittings. A pitman arm is a specific component of the steering mechanism itself, while adaptive and compression usually refer to different concepts unrelated to lubrication fittings. Understanding these terms is crucial for recognizing the components and their functions within automotive systems.