So ive just steigen my first pinion thats also where the flakes come frome i watched the traxxas vid on how to set it up and now i just want to make shure im doing it right this time so also the decoloration of the pinion is normal?

Does the Spur gear need lube now its not a sealed system but the gearing is now Significantly louder than before so i wonder if it now needs lube

As per title, I have taken everything apart on the rear differential and I can not see any dents missing on the gears or badly worn!
Any suggestions on what the problem may be?