I have an older F-150 that is only driven when we need a truck, it is a '95 with the E4OD (precursor to the 4R100).
I bought the truck with 164k on it a couple of years ago, it now has 181k.
Prior owner claimed the oil and filter had been changed in it, and it was bright cherry red and smelled new.
Fluid has smelled and looked OK up until our high speed trip last weekend (225 miles one way at about 70mph). Inspection upon returning home revealed fluid that looks fairly red on the stick, definitely red when light is shown through the drop at the bottom, but is between red and brown on the paper towel. It may smell just a little burnt now, it didn't before the trip. It does still also smell a little "chemical-like" like new ATF smells.
Transmission still engages normally, shifts are a bit sloppy but no more than is normal with an E4OD. They desperately need shift kits and this may be getting one if I determine it has some life left in it.
Has the fluid gone too far? --
1. Should I not change it for fear of the transmission going out soon after?
2. Should I just drop the pan and change the filter
3. Should I do drop pan and filter AND drain the TC too (it does have a drain)?
I do have another E4OD laying around that I know is reasonably good but I would have to go through the work of swapping the tailshaft, it has the 2wd one and I need the 4x4 one.