mine was identical symptoms i looked at rotor arm twice and didn't notice anything on very close inspection the rotor arm buried track from brass centre to brass tip was blown away (Burnt away) this was just over a year old and decent Brickwerks one too. i managed to buy a couple of new genuine roto...
no drain plug on T25 auto box remove sump to drain and replace filter then fill through dipstick tube. both very easy Gasket and filter available from Brickwerks (you can clean the filter with spray brake cleaner but rubber sump gasket needs replacing every time. also make sure sump is not distorted...