1995 E300 Diesel 80k miles
124 body style with 606 engine.

I sometimes get a clunking during hi-way shifts, and shifting from park on hills.
I also have a slight rollback shift into park if not on level ground.

I was wondering is this sounds like a Flex disk on drive shaft or something in the transmision or rear end?

How do I diagnose?

Thanks in advance for your thoughts,
Jack