I have a 98 Discovery and sometimes when I put it in park it makes a popping sound and rolls quite a bit more than usual. It doesn't do this all the time though. Worries me but I just make sure and put the parking brake on. Any ideas?

 

One idea.

Parking pall mechanism.

It's in the extension housing.

Can be rebuilt.

With a copy of the service manual called the Rave you would be walked through the process of the repair. Google "Rave".