Originally posted by stepmar2:
You are only supposed to change the fluid every 30,000 miles and I suggest using some Lucas Transmission Fix with the next change. I does work. 
I don't know where you got your information from but if you wait
till every 30,000 miles like I did, your tranny won't last.
AND... the FORD MANUAL states that the fluid should be CHECKED every 5,000 miles.
Any sign of change in the Oil's Properties, the Oil should be changed.
The recommended ATX Oil change interval, with
NO CHANGE of Oil Properties is 30,000 miles.
Someone over on the NECO sight figured out, that with the heat output of the CD4E,
and the life expectancy of MERCON with that amount of heat,
that the LONGEST and SAFEST interval for retaining your ATX Oil was 12,000 miles.
Remember every 20 degrees over 160 deg F, shortens the life expectancy of ATX Oil by 1/2 of its life !!
Since the tranny is cooled by the Radiator, the MINIMUM temperature of the radiator is 180 deg F.
That reduces the 30,000 mile ATX Oil change interval to 15,000 miles.
My Coolant is always at 200 deg F, so that would reduce my interval to 7,500 miles.
With the addition of the ATX Oil Cooler, the fluid temperature
barely gets over 160 while I am driving on the highway.
Adding an ATX Oil Cooler will allow you to go FURTHER on your oil but,
he still suggested that it be changed at 15,000 miles intervals at the most.
Using any additives in your ATX Oil to swell or condition the seals is just asking for trouble or early failure.
Mercon, or any equivalent or better synthetic ATF Oil for FORD, is all the CD4E needs.
