So this might be a long one but I appreciate anyone who reads this all and can help. Long story short I have a 97 f350 dually 7.3 with the e4od. The old trans acted funny until it finally went out and I put a new trans and heavy duty torque converter in it. All was well for a while until it started getting hot outside. When I got off work I would drive about 10-15 minutes to the gas station, just long enough to get fully warmed up and then I would park it for a few minutes, grab a drink and get back in the truck and it would slam gears when I left. Almost like it heat soaked when I was in the gas station. It did this a few times and the OD flashed but if I shut it off and started it back up the OD stopped flashing but it still shifted hard unless it cooled down for a few hours then it was fine. I had it scanned at a diesel shop and he said there were no codes in the truck except for the vss. So I replaced the sensor, the wiring harness to it had good voltage and I even replaced the tone ring which made the bouncing speedometer a lot better although it still twitches slightly. The truck did fine for a week or 2 then acted up again but if it wasn’t blazing hot outside like the high 80s it was fine. I also found a broken ground strap from the frame to the body and replaced it and checked all other grounds. I also replaced the neutral safety switch and adjusted it correctly, new cooler lines, and a bigger trans cooler. Now onto present day, I just got home from work and was cruising 60 and I noticed it was taking a little more throttle to keep up so I got into it a little and let off to cruise at 60 again and it was cruising about 200-300 rpm higher than normal then I felt a slight thump almost like the torque converter locked up but it’s never done it that high in speed and rpm and then I look down to see my OD flashing but the truck is still driving fine. I drive another 3 minutes to my house and I have a long driveway so I got into the throttle and it slammed second gear again. I parked the truck but left it running and used my laser thermometer to check temps on everything. The trans case read around 160-170 Fahrenheit and the rubber line going into the cooler was about 160 coming in and 140 going back out to the trans. But here’s the kicker. I just installed a Downpipe but haven’t finished the rest of the exhaust system yet so the hot exhaust is blowing right on the stainless cooler line leading back into the trans. That line right at the trans read about 165 so you could pretty much say that after the fluid gets cooled it still goes back in the trans at 165 degrees. I plan on finishing the exhaust tonight so it’s not blowing on the trans and putting some heat wrap around the exhaust, as well as a fluid and filter change in the transmission. I’m not sure how hot these are supposed to run but even at 165 that doesn’t seem bad. Any words of wisdom? If you made it this far I truly appreciate it

 

The normal temp for this trans is 60-100°F above ambient, so your temperatures are fine.

The ONLY way to fix this is to get the codes. The code that set a while ago isn't relevant any longer. You need to read the codes each time that it misbehaves.

A great way to read codes is Forscan. You can download it free at www.forscan.org. Their page shows how to select an adapter to plug into the OBD port. I bought mine for less than $30 from Amazon.

Without the codes all I can tell you is that something is wrong.

 

thanks for the help. That’s an issue is that I’m having a hard time getting it to a shop because I never know when it will act up and once it does I can’t shut it off or it clears the codes. I’ll check out that scanner for sure as most I’ve found for these trucks cost a pretty penny