Do you know what carrier you have 741 or 742 or 489.
741 and 742 uses a solid spacer and shims to set pinion bearing preload, not considering any damage done from being loose, you can just remove the nut/yolk install new seal with some sealer around the outside,reinstall yoke recommend a new pinion nut and torque to over 240ftlbs,
489 uses a crush sleeve that is single use only and you need to slowly tighten the pinion nut while measing the torque it takes to turn JUST the pinion, so you have to remove the carrier and remove the ring gear, intall new crush sleeve and seal, tighten gradually until you get the right turning torque for the pinion, then reinstall/set up the ringgear. Not easy but can be done with dial indicator,12" spanner wrench,gear marking compound,
The pinion bearings are probably trash having been run with little or no pre load so it most likely needs to be pulled apart no matter which carrier you have. The numbers are on the bottom of the of the carrier left side near the yoke They are cast into the carrier
