2000 Ford Explorer water in transcooler

2000 Ford Explorer X series VIN 4.0 OHV Auto Trans
The crust of it: around Nov, Dec 2008 it was overheating, radiator
low, no problem.
Found the metal water tube that goes in front of the thermostat had a
pinhole in it.
JB Weld, cut rubber hose in half, and clamp it up, problem solved for
time being.
Later it developed another leak in the same area, and overheated, but
the gauge didn’t indicate it…gee stuck gauge.
Happens to my oil gauge all the time, after a mile or so, it pops up
with pressure, and never any pinging or indication of low oil, or
overheating.
Anyway, here is the crust of the problem now. Arrive at work one day,
and it pukes it guts out in the parking lot, again the gauge isn’t
indicating any overheating issue, and no pinging under power, or loss
of power, it just heaves its guts out. Problem is I filled it with
water on the first leak issue, and check the fluid level fairly often
after the first time. This time it is heaving our pudding…where in
the heck did the oil come from…come to find that the transcooler was
pushing oil into the radiator…wonderful right.
Now the concern is water in the transmission as well, check the
transmission, no water indicated on the stick, no bubbles, all pink
and fine. No shift problems immediate. Later, as I didn’t do it
right then…dummy, is separate the transmission from the radiator and
install a transmission cooler externally. Ok…now one day, it shifts
into reverse funny, check the fluid…now we have obvious water in the
tranny…great. I do believe I caught this within 4 days of it doing
it, and immediately separated the radiator and transmission lines.
Flushed the transmission, installed a new filter. It has been working
well for over a month like this, but the problem is:
When cold, it will shift into reverse as there is no problem at all,
and all forward gears are fine, no indication of an issue.
After driving to work though, approximately 9 miles, it will now
hesitate shifting into reverse for about 5 seconds, shifts hard with a
mild thunk, and go into reverse. Cold, again no problems.
Su after 9 miles the oil has heated up, the tranny has warmed up,
and things have expanded.
Anyone have any ideas of what it could be:
Electronic valve, band adjustment, eventual tranny in tiny parts in
the pan J
Sorry for the long post, but wanted to share the general story behind
the issue.
Thanks for any input