Normally the failure will result in the lock actuator still moving which is what makes the noise and trying to operate the door lock but the lock lever doesn t move through its full range.
Range rover classic door lock broken.
Central locking failure is not uncommon on old range rovers and discoverys but it s seldom a serious or expensive issue.
This is also probably the best way to replace a broken lock cable this is cove.
This video shows how to remove the outer door handles on a range rover l322.
The poor quality springs within your door lock mechanisms wear and can even snap causing these symptoms the springs within the door lock actuator mechanisms deteriorate over time the oem spring is made from cheap metal which wears quickly this wear leads to the symptoms noted above.