hi all..wondering if any one can help or advise... 91 525i automatic

i have noticed the car over the last few days delays in pick- up of gear esp noticable when slowing down and pulling away it has abt a 5 sec delay in sececting the gear i thought it may be low transmission fluid ..so i went looking for the dip stick..cannot locate it ... how do i check fluid levels ??
i was checking the car etc and when i opened up the coolent bottle i saw it was full with oil.. i checked the engine oil lev etc.. its is not low it`s exact on max lev checked the filler cap on the engine to see if their was any froth or signs of water all clear.. the oil is a light brown color no warning lights have displayed any probs ie low coolent levels/ oil prob`s etc i checked the warning panel and it all looks to be in working order...confused ...can any one advise