white smoke when idling at incline...

[sjcruiser]

It does not happen all the time, but once in a while I see chunks of white(?) smoke coming from under the car when idling at an incline (stopping at a red light in D). Here's what I've done:

. checked engine oil & coolant - definitely not a HG issue.
. fixed the leak in power steering return hose (replaced).
(thought this would fix the problem)
. there's always been a ATF leaks when parked - I could see drops formation under the torque converter protective cover. Could this be the drain plug ? (by the way, how many are there on the TC?)
. checked the rubber connection hose at the AT modulator valve - it seems dry and tight.

I'm going to change the ATF and check the drain plug(s) on the TC anyway. This is going to be my first time doing it. How do I turn the crank shaft ?
Some mentioned usage of a 27mm socket (bought it) but I tried and failed since I could not see or feel the bolt at all ? is it really deep inside that requires an (2-3in) extension ? I may eventually have to use a large screw driver to poke the TC

Any tips are greatly appreciated!

Thanks,
Frank.