Ok so this is the issue i know my truck requires dex/merc. I let my father borrow my truck and he noticed that I was low on fluid and the wonderful people at autozone gave him mercon V. I'm planning to change the fluid completely and replace all of it with dex/merc and some of the Lucas trans conditionor. The question I have is how do you refill the torque converter does it have its own fill hole or is through the dipstick ok. Sorry if this seems like a dumb question I just don't have a manual yet and I haven't had a auto trans in years and years.

Btw it's a 90 f150 4x4 300 with e4od
Thanks

 

You refill through the dipstick tube, after draining torque converter and removing pan, replacing filter and re-installing pan just add about 5 quarts of fluid, then start engine and run for about 30 seconds. shut off and add about another 5 quarts. You should then be able to re-start and continue filling until it is full. I think a complete re-fill will take about 15-16 QTS of fluid and 1 QT of Lucas. FWIW for your 1990 the cheap gallons of Dex III/Merc fluid is OK. Or you can upgrade to one of the later greater specs/ but it isn't required.