4R100 Hard 3-4 Shift Question
I'm new to posting on the forum, just been lurking for a few months.
I have been having a random 3-4 or 2-3 shift issue. It's kinda hard to tell because it's very random. Under moderate to hard acceleration the shift will be very hard. It won't do it consistently, usually it completely catches me by surprise. It doesn't matter if it's cold or hot. Sounds and feels like dropping the clutch on a manual transmission. I have a code reader that reads transmission codes and never get anything stored, no blinking OD light, etc. No burnt or discolored fluid, nice and pink. I did try changing the fluid and filter, didn't make a difference. My temperatures run around 130F normal and 150F towing. Other than the random shift issue it works perfectly. I would rather fix something simple first before it destroys the transmission. Reading some other posts I kinda suspected maybe it's a valve body issue, but I would like a second opinion.
Early 1999 F-350 Lariat CC LB SWB 4x4, Upgraded PCM, DP Chip 60T 80E Decel, Ford AIS, Turbomaster, Boost, EGT, Trans Temp Guages, Hutch and Harpoon Mod, Delphi CPS, Prodigy P3 Brake Controller, 9K Fifth Wheel, 175k