On my TD5 the transfer box drain/fill plugs are 1/2" square drive and the gearbox drain plug is a 3/8" square drive (on these l just used a 3/8" and 1/2" ratchet without a socket fitted)
But the gear box fill plug was a splined torx type, and of course l didn't have one, fortunately an allen key adaptor got it off (as l'd drained the oil, see the post above warning about this)

plug 3292 used on the lt77 is something i often fit instead of the r380 one