X2 also check the kick down lever.
I had a 5.0 lever break causing no 2nd gear. If this is the case the trans must be removed as the lever is held in with a pin thats behind the tq conv.
Can't say for certain on 904's but I've changed the band lever on 727's while the trans. was still installed. All ya gotta do is take off the inspection cover and the kickdown lever retaining pin cover plug is down in the lower outside corner. Use a long 1/4" drive wobble extension and you can get it out and back in.
