So I will give you the whole story in an effort to hope make this better...

Customer took the vehicle. Drove it out for the night. Came out and got in and vehicle would not move after put into gear. Had it towed back to the shop and put it in gear and it moved and we pulled it into the shop. Later I moved it back out and it moved at first but then nothing. Tried off and on and still nothing. Transmission has been flawless but this came out of no where.

Thinking it was an electrical issue even though no codes have been stored I ordered another valve body with all rebuilt electronics and installed that. We now have consistent movement all the time. But it shifts like garbage now.

Basically when under mid load or WOT it will not shift out of first gear until you let off the pedal then when it does shift it will go right into 3rd. Then when up to speed it will shift into OD. But if you try to floor it to make it downshift it acts like it wants to go back to 1st gear so I just get out of it.

Thinking it may be a valve body issue I pulled everything out and put the rebuilt electronics onto the old valve body.

Still having the same issue.

The transmission fluid is right and good. No abnormal metal build up. No apparent slippage in the transmission in 1st gear or any other gear that works.

Oh and you cant put it manually into 2nd gear either whether on the upshift or downshift.

Could this be a bad 1-2 shift solenoid? If so, where is the easiest place to get one fast?

 

Sounds like a shift solenoid, or second gear is bad. Transmission shop will be able to help you out with parts.