Originally Posted by SouthArk370Z

After that amount of time the lube was not performing up to spec, even if it looked good. Maybe still good enough for a grocery-getter (most trans/diff lubes are pretty tough) but not what I would want in a sports car, especially if driven hard.

It's a good idea to change all lubes after a short break-in period (say, 1000-1500 miles for motor oil, 10-20k for MT and diff).

But opinions on lubricants (and car audio) are like a**holes - everybody's got one.