there is a video series on you tube done by racer53 on this subject and i found it extreamly usefull as i have burnt out my diff and destroyed the idlers after two months of light use,
I have gone for ceramic answer diff bearings and ceramic bearings on iders, kevlar diff 52t, acetal idlers and team acc diff grease.
after £40 on a diff and the monkey kit only £65

well you know where i am going with this but its worth it not having to keep doing it.
my diff too is a little noisey but feels really smooth
Hope this helps
p.s when setting up the slipper like shown in the video, make sure the slipper isnt too tight, lets just say i took it on the chin