The Stovebolt Site Forums The Shop Area Driveline 1951 3/4T Pinion Rebuild stiff

Hmm... If I understand what you've said, OP, it appears you've solved your problem. You forgot to put the preload spacer in.

I have done stuff like that and once lost a spacer that I couldn't find a replacement for. In that case the adjustments for preload was done by changing the shims under the bearing cups (races) and there was only one size spacer. I tried making one out of a piece of cast iron pipe but it was too soft. In the end, I had to adjust preload by torquing the yoke-retaining nut and estimating the torque required to turn that bearing along with the other bearings when in neutral. It wasn't ideal as the yoke worked slightly on the splines, gradually loosening the preload as the yoke wore into another piece-of-pipe spacer, even with a castle nut and cotter pin but it was a piece of logging equipment and was easy to adjust then needed.