Went for a drive the other day, I hammered the car through 1st and 2nd and let off a little and shifted to third. Cruised in third up the street to a stoplight.(No problems thus far) Took off from the light, shifted to 2nd,(just fine) shifted to third and it was like I threw it into park. Tires locked up. I bumped it into 2nd and drove where I was going in 2nd. When I went to leave I shifted into 1st then when I went to shift to 2nd it just stayed in 1st gear. All I have now is 1st and reverse. Tranny is a turbo 400 with pro tree brake, and full manual valve body. Had about 10 drag strip passes on it when I put it in. Fluid looks fine and is not low and I have never had any trouble at all with it before now. I checked the linkage and it also appears fine. Could this be something in the valve body or is tranny shot?

 

Surely there is some knowledgeable tranny guru who can solve this riddle for me. Don't know if I should pull the whole tranny or not.