noises and diff cleaning ?s

Rear end is making noise, has a auto locker (not sure which) and a solid diff cover, there wasn't any fluid near the fill hole but I don't know if there should be at that level, Im only leaning towards that cause thats the roll of thumb with stock. So, should I fill to the hole? And I am changing the fluid this week, is there something I should use to clean out the old grease. I'm nervous about the locker, when driving it sounds like an air ratchet spinning out a loose bolt. When I did pull the plug there was "stuff" on it, almost looked like teflon tape but dissipated in between my fingers. So I want to clean up in there, what should I use?

what axle are you running?
1. order a lubelocker gasket for your axle
2. pull the cover/drain fluid (look for shavings in the oil)
3. hose out the housing with brakekleen
4. check the little sump at the bottom of the housing for debris, get as much out as possible, i would also take the time to add a magnet here, if it hasnt been done already
5. inspect ring/pinion, locker for any obvious damage
6. clean old RTV off the cover housing for the last time (yay!) install cover and LL gasket
7. fill with gear oil 80/90 or 85/140 for towing, fill all the way until it runs out the fill hole
8. add teflon tape to fill plug, reinstall

Its a 30 / 8.25 combo. That was my intention, cleaning was a big thing for me though wasn't too sure