Will change from low 1 into low 2 but slips a little going into low 2 but wont go in drive could this be a modulator valve the vacuum or the filter? If not then what do I need? This is a automatic 2wd. Vehicle
This will have to be checked over by a qualified trans tech, just make sure that the oil is ok (level & condition) slipping sounds more like an internal problem that will need looking into before any further damage is done.