old transmission gears wont fit on new main shaft

[Tom Bellfoy]

I am at a loss as to what to do now. I am rebuilding a noisy transmission (first, second and reverse gears real bad whining noise) and it wan not popping out of any gear) because of worn teeth on input shaft and bad gears on cluster. I have one set of second and third gears from the noisy transmission and one more set from another transmission that seem to be quite usable. I also have 4 defective main shafts, one from this transmission and three others. With that said I ordered a new main shaft # A-7060 from my very reliable dealer who did state that the new shaft was USA made. Problem is that the second and third gears will not go over the shaft., I did manage to get one larger gear to go on , however it is very tight and I doubt it would slide even with 600 weight oil. My dealer has been helpful to the extent of checking his stock. I am told the new shaft is designed to fit the new gears, nothing said about the old gears being able to fit. So what do I do now, dealer says my measurements are within manufacturers specs. My way of thinking is that Henry made specs so that we wouldnt have to purchase sets of gears, but in this case my 85 year old worn gears wont even go over the shaft. I cant see any burrs on the new shaft or anything to stop the gears from fitting on. Whats my next step ?? Has anybody else has this problem ?