2001 F350 Not shifting into 2nd gear.
I was driving my truck with family in tow from Jacksonville, NC to Evansville, IN, about a 790 mile drive. I got about 300 miles and stopped to get fuel, because fuel is expensive in West Virginia, as I started to pull into the gas station I was on the accelerator and noticed it was revving high kind ignored it hoping it was just acting up a little. But after that I figured out that it's not shifting into second. It will go into 3rd, 4th and back down to 1st just skips 2nd. Anyway I finished the next 500 miles babying it. It did not get any worse or an better. Tranny fluid temp was around 138F, the fluid looked clean and had the right amount. I looked at a couple things I'm hoping it is the accumulator valve body. If so how hard is that to change out on my own. If not is there anything else I can check on my own or do I need to get it rebuilt. I'm in the Marine Corps and have to get back to NC on the 1st.