Have had the gears pulled from the old axles but it turns out the original keys are loose in the new axles. Hmm .. interesting. Anyone else had this experience? Been a long time since I was elbow deep in T guts ... it seemed easier when I did all this back in 1982.
Seems like the axles are defective. Have the vendor replace them with the correct dimensions.
Measure the keyway on the new axle, it should be .250" wide and .125" deep.