Ok after researching and reading no answer to my issue, thought you guys may give it a try. 2000 Disco II 145,000.
I notice this knocking on my disco this morning it only does it when i pres the brake and the car is in park, either with the engine running or the ignition open. once I put it in drive no noise no clicking no nothing, I can move the stick from 1 all the way up to P.
based on the post on XYZ makes me rule out this issue is related to mine. No SES, no lights on the dash nothing.
Here is a link to the video i Took this morning.

Knock on the shifter gearbox - YouTube

I"m leaning faulty relay or light switch but how is this related to the tap on the gear box

thanks!

 

I'm willing to bet good money and say nothing is wrong with your car... Most if not all vehicles with an auto trans built in the last 15+ years have a safety mechanism activated by the brake switch (that makes that very same noise) to disengage the vehicle from park to shifting the car into a moving gear or neutral, not from gear to gear, just from park. It's done that way so your foot is always on the brake when shifting out of park and by association, the car will not move in case you or someone else accidentally moves the gear lever without the driver's knowledge.

 

That is your neutral safety switch. It is there to prevent you from shifting out of park without pressing your brake pedal. When you press the brake pedal the switch pin disengages allowing you to shift out of park. It is required by law.