2004 disco front diff issue
 

I own a 2004 landrover discovery have had from new. Done 75000kms. checked oil in front diff, was discoloured. Drained oil & found part of a roll pin approx 3mm diameter & 6mm long on the magnetic drain plug as well as 1 piece of metal approx 10mm long x 1 mm wide x 0.02mm thick also copious amount of super fine metal almost like a paste stuck to the magnet. The oil has heaps of fine metal suspended in the oil, the oil is almost a silvery colour. Obviously there has been considerable wear in the diff, can anyone advise where the piece of roll pin may have come from. Is anyone aware if this is a common fault with disco II diffs. I live in the Pilbara region of North western Australia & the vehicle does some serious off road work at times but surprised to see this amount of metal in the diff

Drained rear diff this appears fine has ARB air locker fitted only minor indications of metal in oil from normal wear