Umarali, part number for diff and trans case sealing washers...
Front diff fill and rear diff fill and drain 12157-10010
Front diff drain 90430-24003
Transfer case fill and drain 90430-A0003
For some reason, there are no magnets on any of the plugs, so Tundra plugs with magnets (flush with the plug for drains, extended for fill) are, I think, reasonably priced upgrades.
You have 4 choices, depending on if you want a plug with a socket for a 10mm Allen wrench or a 24mm (actually, 15/16" works and fits just a little tighter) 1/2" drive socket...You can also get either variety with a long magnet or one that's flush with the end of the plug. The short ones are used for drain plugs and the TC fill plug, and the longer plugs are used for the diff's fill plugs.
10mm drive, long magnet 90341-18035
10mm drive, short magnet 90341-18021
24mm drive, long magnet 90341-18040
24mm drive, short magnet 90341-18057
I'll be draining the diffs and TX later this week when my driveway dries out from the rain.
I'm also taking a very long look at the Motive Power pneumatic filling tool for stuff like this...cheap for the time and mess it will save...wish I'd known about it years ago...
http://www.amazon.com/Motive-Products-1730-Fluid-Transfer/dp/B00I6BG1KI/ref=sr_1_1?s=automotive&ie=UTF8&qid=1445294785&sr=1-1&keywords=motive+products+1730
hth
Steve