I've been having issues with my 95 F150 (2WD) 4R70W ever since I got it. When I first got it, it would hunt back and forth when it was time to upshift into OD (or converter lock up hard to tell which) I flushed the trans, converter, and cooler and refilled with Mercon 5 fluid. That problem went away.
Now I've noticed it requires heavy throttle opening before it will downshift when climbing a hill. It will slow way down if only gradually depressing the throttle and requires almost 3/4 to full throttle to downshift (unlock t/c). I'm used to my 79 (with a C4) and 63 (with a three on the tree) that only requires the slightest pressure on the throttle to maintain or accelerate up hill. Now I realize they are non OD but I'm thinking the 4R70W should downshift (or unlock) much easier that it currently does.
Has anyone else experienced this issue? Do you think a rebuild would fix this issue or could it be in the ECU/wiring/connectors?
This may not even be a transmission problem, this kind of issue is best diagnosed with the use of a scanner that will allow monitoring of the data stream for the transmission and engine. Tps, road speed, engine load, and other factors can effect the way the computer controls the transmission.
Thanks for the replies. I'll be sure and check for codes once I get it back on the road. I'm dealing with brake issues and I found a snapped leaf spring center pin today as well.
I don't think I can communicate with the trans (or even the ABS) with my scanner. This is a 95 so the OBD II data stream wasn't availaible til 96 if I'm not mistaken.