Movano B steering is stiff and makes a crunching noise when turning

A crunching or grinding sensation, or perceptible notches through the steering wheel while turning, without power-steering pump whine or a falling fluid level, indicates a worn steering-column universal joint. This joint connects the steering shaft to the steering rack and operates at the bottom of the column, where it is exposed to moisture, salt and dirt. A worn or corroded joint transfers jerks directly to the steering wheel, most noticeably when manoeuvring and driving slowly.

How can the universal joint be distinguished from other steering faults?

The nature of the symptom identifies the cause. A whine that becomes louder while turning at a standstill points to the power-steering pump. Knocking over uneven surfaces that disappears on a smooth road points to track-rod ends or anti-roll bar bushes. Resistance and crunching felt only through the steering wheel, regardless of the road surface and also present while stationary with the engine running, indicates the universal joint. Do not postpone the repair: advanced joint wear causes detectable free play in the steering. The advantage is that the universal joint is a separate component, so the complete column or steering rack does not need replacing. Protect the joint from moisture after installation.