Recently I changed the FD oil and sent a sample off for analysis (Castrol 75W90). Results returned a reading of 69 ppm for Fe (Iron). When the megnetic plug was inspected at the time it had nothing except the "fuzz" on it, but when I left some oil in another clear plastic sample bottle, after standing for a week or so there appeared to be dark deposits suspended throughout the oil. So I took a very strong magnet and taped it to the side of the sample bottle, waited for approximately 2 hours to check and guess what ?...... the oil was crystal clear with all the fuzz over at the magnet. So the fuzz is not aluminium, it is iron based (magnetic) which means of course it must be from gear surfaces or bearings. I have just completed 10,000 Km's in the last month and dropped out the FD oil again. It came out darker than the previous sample which had done 3000 Km's. Sent off a sample to the lab, still awaiting the results, but I have repeated the magnet test and again the oil has cleared off but this time there is a larger amount of fuzz to the side of the bottle (same size bottle and sample volume). I believe I may have discovered a very early failing of the crown bearing and am now tempted to open the FD casing to see what shims exist. I have no measureable wheel movement, no oil leakage, smooth rotation and a new FAG 61917 c3 bearing in my tool box. Thoughts please gentlemen ?