Hello peeps,had a strange happening today,all going well,gearbox working normally, slowed for roundabout, got on to dual carriageway and it wouldn't do tc lockup,revved normally, did the lock up in third,went into 4 th got up to 60 and it didnt lick up,usualy does it at 53/55, its had new fluid and a filter about 6 months ago and been spot on until today,any ideas?