While what Murc and the master have said are true, you can alter the stock white diff to behave just like the AWD red one. One way is to pack it with AWD grease, or chapstick or play-dough. Ball diffs will go out over time, especially when if you are gonna run crazy power and motor such as anything with the lithium io / poly combo. I run a white diff in my AWD with the yellow arms. Matches the yellow skyline body.
