Possible Diff failure

[joffa1]

Hi guys,

 

I stupidly neglected doing my diff oil for a long time and am getting some pretty bad noises which I think are diff related (2012 FG Turbo Ute 6 speed manual by the way 205,000kms). 
 

I first thought it might be a wheel bearing as sort of sounds similar to when I’ve experienced that in other cars in the past but what’s different is it seems to be louder/worse when I back off the throttle or when I push the clutch pedal in particularly when changing gears at the 70-100kmh range. 
 

Any ideas on what this might be and whether I can do any self diagnosis at home? 
 

Thanks very much for any pointers/advice. I guess any recommendations on where to take it for repairs in Melbourne would be r helpful too.  
 

cheers.