ATF Overflow

[khalidm3]

hi all..a forummer PMed me questions about ATF, which reminds me of my own exp. 3 weeks ago, after replacing ATF (GM gearbox, FYI), going at 140kph, suddenly a large amount of white smoke came out from underneath my car. I tot my car was on fire. Panickly, i called my mech, he said it is from my ATF. the gearbox has an overflow pipe or hole (donno), which expelles any excessive ATF. The overflow, happens to drop on the exhaust sys, which explains the smoke. The mech then buang some ATF later (about 1 liter). Last week, when i serviced my radiator, i added 1 liter of ATF since i lost some when they removed the radiator (ATF cooler attached to it). Then it happend again, but with less dramatic smoke. question1) is there really an overflow pipe? if there is, issit better to just leave it or can it be sealed?2) apart from a dirty undercarriage and sprinkling ATF to the car trailling me, will there be any side effects on the gearbox?anyone have similar exp ?thanks all...