2007.5 3500 all deleted.
New to me - no real clue on its history.

6.7 with the 68RFE.

I've been driving it for about 1000 miles.

Short story;
The transmission would occasionally go to 5th or 6th but would mostly stay in 4th.
It would run through 1, 2, and 3rd but would just stay in 4th (the gear indicator would not show any number like it does when it’s in limp mode).

I changed the valve body out with a refurbished one with a new solenoid (supposedly). It came off eBay.

Now, the indicator shows 4th gear (limp mode) but it will not shift out of 1st.

My next step is to throw the old valve body back in and see what that does but wanted to ask here if anyone had any suggestions.

Thanks!

 

I'm no expert but can tell you what I know. My 2007 68RFE would go in to limp mode after the trans fluid went to 150 deg or higher. I didn't catch on to that for a long time as it normally runs way below that temp and the dealer and tranny shop had no clues as it would drive like a dream below that fluid temperature. After a lot of checking on the internet, we decided the valve body was leaking internally when it go over 150 deg and would trip a code saying that the overdrive clutches were trying to engage when they shouldn't be. So, a refurbed valve body AND a gasket installed in the valve body solved the issue completely. We also installed a solenoid pack since we were in there anyway but didn't think it was a cause of the trouble. This is just food for thought for you in case it helps.
Now about your truck that is in 1st gear and won't shift to 4th. Are you sure you are letting it rev high enough to shift to 4th? Seems to me it might go to 2500 rpm or maybe higher before it will make the shift as I didn't clue in until I let it rev and it shifted. Also, do you have any codes thrown?