possable vcu or bearing gone ???

ive not had this car long so dont know much about its past but its started makeing a strange creaking noise which sounds like its coming from the drivers wheel.
now this noise is speed related and sometimes comes with a freind in the form of a clunk! again speed related. the clunk can only be heard with my head hanging out the window and i cant feel anything through the steering.

ive jacked it up and everything feels tight ie no play/wobble.
just a note though i read on another thread that the vcu locks the front diff when its gone and i did notice that i couldnt turn the wheel when it was up.
could this be what im heering? is it a big job to change and how much would i expect to pay?
its a 1996 4.6 p38

viscous coupling rtc6044 same as coupling in rrc,about £400 new can be fitted with transfer box in vehicle front prop bolts directly to it at transfer box,needs to be checked with large bar on nuts to turn wheel,viscous locks front and back axle together when seized unseized will allow movement for cornering

thing is it realy does sound like its coming from or near the drivers wheel

if you cant turn wheel with one front one jacked up gearbox in neutral then viscous is seized and best changed before you have to change diff ,to test wheel brg as modern ones dont allways have play for you to feel remove brake pads and spin wheel