diff oil!!!

hello,

i have owned my landy for 6 months now and have taken it wading a few times and i just had a spare half hour so i thought i would change my rear diff oil.
when i drained it it was light grey and lumpy. when it had finished draining there was a yellowy, orangey colour almost gritty foam,on the surface quite hard to explain i will try and get pics.

Any ideas what this is? should i be worried or is it just normal over time. Cheers thanks max

It's water in the oil.
Check your breather is clear and high enough to be clear of the water when you go wading.

What he said - it's the water rusting the metal particles that are in the diff.