I know Ford says the fluid is good for 100K+ miles, but IMO that is total BS. Change the fluid for sure. Fresh fluid may eliminate the problem. If this is the 6 speed tranny, the filter cannot be changed without dropping the tranny and splitting the tranny case.
Thank you, that is what I had just read that Ford says 100k but most professionals say 50k. That filter you mention. Is that a necessity/recommended to replace also? Around how much $$ are we talking to drop and open the transmission? I don't see it just giving out mid-drive. It is relatively minor now and I'm more apt to maybe just do a fluid change and get rid of when the symptoms become more serious. Last, going slightly off-topic but for my car I was told to do 3 drains/fills. Is this what you recommend or is that a bit overboard (looking at $90 for 9qts since I have to use proprietary fluid).
Yes, 6-speed, this is my father's I forgot that they aren't 5. Looks like it is the 6F50 and 6F55 was for the turbo.
My symptoms were only on the highway when I would try to accelerate without dropping down a gear. If I got the rpms up by hitting the gas and dropping down a gear it would seem fine. So, under load above 50 mph it really felt like a trans slip and I was 99.9% convinced that it was.
I was about to say that acceleration without downshift is perfectly smooth. At the same time, if I floor it at 60 I sense no slip. I need to test it again when I'm back over because I think you are right now that I think about it. There is jerkiness coming lightly out of overdrive but I think it is also there even without dropping out of OD
under light load. I need to check when plugs were changed last anyway. Cops are the coils and UI gasket is the head gasket?
Edit: Regarding testing it again. It absolutely is jerking under light load without the downshift.
Edit2: Regarding 3 drain and fills tracked down a reasonable answer:
One drain and fill gives you 43% new fluid. Second D&F leaves you with 68% new fluid. Third D&F: 82% new fluid