Your trans is overheating and dumping the heat expanded fluid, it is overheating because of slipping clutches.
your torque converter, bands, forward clutch packs can be the problem.
The O-D servo is on the outside of the trans closest to the bell housing. look for a round cover about 2.5 inches round. remove the snap ring, fenagle the cover out (dont scrach the bore or you will have an external leak), the moving portion of the servo is black rubber w/ a pin attached to the center, inspect the lip seals large and small for cracks, splits, missing rubber, firmness (if its hard it needs replacing) if you find any of thies, it needs replacing. take the servo and the cover to your local trans shop and get a new one also get a new O ring for the cover.
the valve body may be leaking and not applying adaquite pressure to the forward drums, there could be bad seals at the drums, and the drums could be leaking past the O ring seal.
T.C. when its a cold startup and you hear a wineing tapping sound comming from the floorbord and gets more pernounced with RPMs and load but quiets down when warmed up you T.C. is bad
Hope this helps...