Hard 1st to 2nd when warm

[93 K1500]

So I cant get this figured out First thing in the morning shifts fine in all gears, After ten min. it slams into second gear all the other gears still shift just fine. Its only 2nd. I have changed the tps checked fluids, all good no burn smell nothing. Has new steel driveline new yoke new u's I am ready to kick this trany down a big hill. oh and no problems when downshifting???

 

[93 K1500]

Nobody's even gonna guess- Welcome to my world

 

[93Chevy_1500]

I had an s10 with a 700r4 4x4 trans and it did this turns out the tranny pump was gone. It would tick lightly when it was idling as well you could hardly hear it.