When making very tight turns at very slow speeds like parking and usually on a slight incline my rear differentials would stick slightly and then release causing the the whole back of the van to clunk, vibrate and judder alarmingly. This would only happen after driving for a while and not when the van was cold.
I have since changed the diff oil and the problem seems to have gone away almost completely
I think I might change the oil again in case there's anything still in there that may need flushing out. I didn't see anything when the old oil came out but it had a milky metallic sheen if stirred which the garage said meant there was metal in the oil (presumably from the cogs). The garage and I originally thought there may have been a problem with the spider gears. And there may still be.
Would be interested to know whether anyone else has had similar experiences?