i think i see or heard this just 1X recentyly in 4L60E in 97 Jimmy, but also have added VALVOLINE max LIfe ATF DEX MERC synth. after a service and repair on that unit, and had not hada single problem in 10K mi. untill one time recent
where i got all the way home and tried to pull into my parking and my driveway and had the CEL witha code that
said TORQUE CONV, and Up - down Solenoids 1 and 2, Guess what sure Nough, next morn went to check the Fluid
i was down at least 2 pts ATF , added more Valvoline, then drove just fine, that was a week ago, been driving fine;
4x4 is great , snow and ice in Oregon in winter worked, PEERRRRFECT./. the reason the fluid was low was we put in a radiator 3.5 months ago and it just needed the 1 Quart Topped off Plus an additional two pints more, and there
arent that many bad leaks, maybe a minor one and it could be OIL at Rr main seal or it could be atf out of the TC at mateing of ENG TO TRANS. cant tell for sure, but, its maybe 1/2" high on the 4l60e dipstick right now and running strong , hope it doesnt hurt to be that 1-2 millimeters high in the Trans cause so far... so. good LOL