Whuring 300tdi

Good evening chaps my 300tdi has a annoying whuring/whine at between 50-70 shuts up at over 70 and when I lift off it's not what I would call a grinding sound. It is deff from underneath and towards the middle or front, auto gear box works fine and smooth (as smooth as s old 300 ever will be lol) diff lock fine. Any ideas?

its quite common for older autos to have gear whine ,check oil in t/box

Done and seems fine, oh saying that the gearbox dip stick blows out by a couple inches everytime I lift the bonnet the bloody thing is poking out a bit

check breather on passenger side rear housing 9/16 14mm spanner ,check oil level running in neutral

mines doing exactly same but between 40-50, i think maybe a fluid change is in order

I'll give a fluid a go I might try a heavier oil, someone said someting about bearings but to be honest it could be any bloody 1 so I don't wanna go just changing bearings randomly and pointlessly if they don't need it, someone else said tranny box

dont put any oil other than atf else you will have problems ,there are no bearings in auto box apart from thrust bearings between epyclic gear sets and clutch packs and these hardly wear

Mine was making a similar noise. Check your propshaft rubber (cush drive). Found mine was knackered again due to A frame ball joint being U/S. Just a thought.

Have you tried coasting in neutral?