My friend just bought a older tko tranny for his fox mustang, now the input shaft is 26 spline while the output shaft is 31 spline. The slip yoke he has is a 31, but there is a notch in it, but when you look at the output shaft on the tranny there is no notch. Are we susposed to hammer it on or is it susposed to slip on really easy, something doesn't seem right. Can't get this thing on to save our lives. any help is greatly appreciated.